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Category Archives: Basics of VBT

Movement quality has been a hot topic in the strength and conditioning field for years. The quality of movement has an effect on athletic ability and injury prevention. The Functional Movement Screen (FMS) is the leading movement screen for athletes and the general population.

 

The FMS is able to quantify efficiency in different movement patterns to give the evaluator an idea of how well an individual moves and gives us insight to look at the body’s joints for dysfunction. It is another objective measure to help determine performance. Using another objective measurement device, we can determine if VBT and Movement Quality can work together to improve athlete performance. And if return to play protocols using VBT can help.

 

MOVEMENT QUALITY AND FORCE PRODUCTION

A major question around movement quality is if the body can provide maximal force when joints are not in alignment with their stable and mobile nature? If the knees and ankles are unstable in a squat, it’s like trying to shoot a cannon out of a canoe; The body is being asked to perform a stable task in an unstable environment.

This said, movement quality matters, especially when maximizing intent in the weight room. Coaches sometimes err away from VBT because when an athlete is challenged to move fast, form can slip. This is why we emphasize that VBT is a great tool to help provide objective guidance around loads, but coaches are still needed to coach. In this way, movement quality is retained. Therefore, VBT and movement quality can go hand in hand, the extent to which is up to the coach.

 

INJURY AND RETURN TO PLAY USING VBT

Returning to play after injury is an enormous field of research. Assessing movement quality subjectively and using VBT for objective data can alleviate guesswork in this process. A common injury across sports is anterior cruciate ligament (ACL) tears. Knee instability is commonly found post ACL surgery. Due to this, in return to play protocol it is common practice to evaluate individual limb differences with force output.

Researchers Ardern et al. found that after an ACL reconstruction surgery, only 63% of 5770 athletes were able to return to their pre-injury level of play. These individuals were evaluated using strength metrics but not power. In addition, Researchers Angelozzi et al. found that even when strength levels returned to normal post-ACL reconstruction, there were still significant deficits in rate of force development 6-months afterward. 

 

VBT AND MOVEMENT QUALITY

VBT devices can shed light on differentiation between lower body limbs. And Perch specifically is able to categorize unilateral movements and assign velocity and power metrics to right vs left limbs. Therefore, coaches can use these metrics to gain insight into individual leg differences in force development. 

For example: using a single leg jump protocol, Perch can measure the velocity of a single leg vertical jump. Additionally, we know the less force put into the ground, the lower the velocity of the bar. From this we can then get an idea as to unilateral differences in stability and rate of force development. This insight into athlete movement and rate of force development could prove invaluable when making programming decisions for our athletes. In turn, this can help them return to play safely and functionally.

 

CONCLUSION

Could movement screening paired with velocity screening provide us the looking glass we need to spot deficits in athlete rate of force development? Bridging the gap between movement quality and accurate analysis of force production could be the next best way to keep our athletes safer and stronger on and off the field.

 

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SOURCES:

  1. Ardern, C. L., Webster, K. E., Taylor, N. F., & Feller, J. A. (2011). Return to sport following anterior cruciate ligament reconstruction surgery: a systematic review and meta-analysis of the state of play. British journal of sports medicine, 45(7), 596–606. https://doi.org/10.1136/bjsm.2010.076364

  2. Angelozzi, M., Madama, M., Corsica, C., Calvisi, V., Properzi, G., McCaw, S. T., & Cacchio, A. (2012). Rate of force development as an adjunctive outcome measure for return-to-sport decisions after anterior cruciate ligament reconstruction. The Journal of orthopaedic and sports physical therapy, 42(9), 772–780. https://doi.org/10.2519/jospt.2012.3780

Determining an athlete’s 1RM is an important part of developing a training program. A 1RM can help coaches program appropriate loads through training cycles. They can then retest the athlete’s 1RM to determine if the athlete got stronger. With new technology, it is possible to accurately predict athlete 1RMs. This allows coaches to assess athletes within lifting sessions and saves time otherwise reserved for testing days. There are multiple ways to do this, but this is our favorite.

 

THE PROBLEM WITH 1RM TESTING

Traditionally, the maximum load an athlete can lift without failure has been determined just like that: the athlete performs an exercise with progressively heavier loads at maximal effort until they no longer can. This poses 3 primary concerns:

  1. Time: Coaches testing all athletes on the team takes time. Each athlete must keep lifting increasingly heavy weights until they no longer can. While there is something to be said for the energy in the weight room, this requires coaches to set aside valuable training days to test performance, instead of assessing while training.
  2. Injury Risk: As athletes try to go beyond their 1RM their risk of poor form and injury has been shown to increase, particularly in novice or untrained athletes [1].
  3. Fluctuations: A 1RM can change by up to ±18% day to day due to stressors, fatigue, lack of sleep, or a really good day. The percentage fluctuations are usually much less than that, the fluctuations can still be significant in the grand scheme. Additionally, an athlete should be getting stronger throughout the workout program so any prescribed weights based on the 1RM measured at the beginning of the program are no longer accurate. Prescribing a workout based on the initial 1RM will not account for daily fluctuations or strength gains, potentially leading to under or over training [1].

 

A WAY TO PREDICT 1RM

VBT offers a solution to all of these concerns. An estimated 1RM can be calculated quickly and easily over the course of warm up sets. These MUST be done with maximal intent for this to be an accurate number. Research by Mladen Jovanovic and Dr. Eamonn P. Flanagan determined a simple linear model that can predict 1RM from lighter loads: 

  Load = m(Velocity) + b

In this equation, velocity is equal to the mean velocity for the set at the prescribed load, and m and b are the slope and y-intercept. Using this, an athlete can perform a few warm up sets at their maximum velocity and use the mean velocity output by Perch to solve [1]. This can be done easily with a little bit of algebra, or by using a graphing software. It is also forthcoming into Perch software. To determine the 1RM, plug in the expected velocity for the 1RM, and solve. Voila – an estimated 1RM!

 

SO WHAT IF I DON’T KNOW AN ATHLETES 1RM?

If an athlete’s 1RM velocity is unknown, there are two options:

  1. Perform a set below the 1RM to failure using Perch. One of the many cool things about VBT is that the minimal velocity threshold (MVT) for a given exercise is pretty standard regardless of load [1]. This means that the velocity of the last rep before failure at any load is a good predictor of the velocity of a rep at the 1RM. 
  2. Use the generally accepted MVT for an exercise. For a bench press, the average MVT is 0.15 m/s and for a back squat the accepted velocity is 0.3m/s [1]. Obviously, these are averages and fluctuations between athletes are expected.

CONCLUSION

Jovanovic and Flanagan’s formula is a good estimate of 1RM. It is also easy to employ in the weightroom each day to tailor an athlete’s program to their 1RM on that particular day. It can account for increases in strength or an athlete having an awesome day, or stressors that are causing an athlete to not be at their peak for a particular session. 

That said, it is never a bad idea to perform a true measure of 1RM from time to time. Do this by one of two ways:

  1. An athlete lifts a lighter load until failure, measuring velocity, and using a 1RM predictor. OR
  2. An athlete lifts heavier loads until they no longer can [1].

Doing both will help check the accuracy of the formula and make sure athletes are getting what they need out of the training program [1]. Lastly and still incredibly important, testing 1RM can be a fun and competitive training environment to enhance team camaraderie and maximal performances!

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SOURCES:

  1. Jovanovic M, Flanagan EP. Research Applications of Velocity Based Strength Training. Journal of Australian Strength and Conditioning. 2014;21(1):58-69. 
  2. Baechle, T., Earle, R., & National Strength & Conditioning Association (U.S.). (2008). Essentials of strength training and conditioning (3rd ed.). Champaign, IL: Human Kinetics.

Here at Perch, we talk a lot about lifting heavy things fast. That is because power relies equally on force generation and velocity. Power equals force x velocity: P=F*V. Developing power in athletes can be confusing, in this power we try to break it down into digestible bites.

 

Power is also arguably the best single measure of an athlete’s overall performance. Lifting heavy loads is only half the equation, just like lifting quickly is also only half the equation. To be a powerful athlete, both the force and velocity components must be developed.

 

DEVELOPING POWER WITH ATHLETES

 

Developing an athlete’s power output across a wide range of loads will help translate weight room sessions to sport specific performance. Research suggests that training at the load that maximizes power output is the most efficient way to develop power at a wide range of loads [1,2]. That said, you must also learn how to recruit muscle fibers with max strength and accelerative-strength/hypertrophy zones and traits. And recruit them quickly with starting strength and speed-strength zones and traits as well. 

 

5 CONSIDERATIONS TO DEVELOP POWER WITH VBT

 

Velocity based training devices like Perch can help guide training within your maximal power zone to optimize protocols for you specifically. Remember, the peak power zones span across speed-strength and strength-speed in VBT. This is approximately 0.75 to 1 m/s for strength-speed, and 1 to 1.3 m/s for speed-strength. Maximal power output lives in that zone!

  1. Monitoring: Perch can help determine load with max power output! You will know in watts what your maximal power output is by using Perch and monitoring data over time. This will guide the velocities and loads at which you are most powerful, and what is optimal for you to train at.
  2. Base Loads off of Adaptations: Loads do not have to be based on percent of RM. We know this, but still worth stating. If your loads are based on velocity ranges and specific adaptations you are better off. This will help inform your maximal power outputs instead of just load lifted.
  3. Sport Specific Traits: Understanding the needs analysis of the sport will help you develop power specific to those needs. If an athlete needs a ton of strength, err towards those zones and traits. If they need more speed, err towards those. This is the art of coaching!
  4. Live in Power Zones for Power Development: As stated above, speed-strength (0.75 to 1 m/s) and strength-speed (1 to 1.3 m/s) is where you want to live for maximal power output. To develop power, however, you will want to work across all loads and velocity thresholds. You have to be strong and be able to recruit muscle fibers, but you also have to be fast and recruit them quickly. Working on developing those specific adaptations within their zones will help elicit power.
  5. Maximize Intent: Above all – always lift with maximal intent! Max intent is necessary to be making those neural connections so power can continue to increase. If maximal intent is used, rate of force development across all loads will be optimized. In this way, progress begets progress.

Most of sport is centered around power, as is most athleticism. If you do not know when you are training power, it is hard to optimize training protocols for it. VBT devices can take the guesswork out of your training. With more precise protocols, training is never wasted, and never guessed. We can maximize sessions with exact knowledge via VBT devices like Perch. Train for power, and know when you are doing so!

developing power

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SOURCES:

  1. Kawamori, N., & Haff, G. G. (2004). The Optimal Training Load for the Development of Muscular Power. The Journal of Strength and Conditioning Research, 18(3), 675. https://doi.org/10.1519/1533-4287(2004)18<675:totlft>2.0.co;2
  2. Moss, B. M., Refsnes, P. E., Abildgaard, A., Nicolaysen, K., & Jensen, J. (1997). Effects of maximal effort strength training with different loads on dynamic strength, cross-sectional area, load-power and load-velocity relationships. European Journal of Applied Physiology, 75(3), 193–199. https://doi.org/10.1007/s004210050147
  3. Suchomel, T. J., Comfort, P., & Lake, J. P. (2017). Enhancing the Force-Velocity Profile of Athletes Using Weightlifting Derivatives. Strength & Conditioning Journal, 39(1), 10–20. https://doi.org/10.1519/ssc.0000000000000275 

What goes up, must come down! This is true in gravity and in weightlifting. However, it is not always controlled outside of the weight room. Because of this, eccentric training is critical for athlete and force development. Eccentric training is the lengthening muscle action. It is arguably the most important part of a muscular contraction to indicate resilience to injury and overall max strength.

 

Eccentric training protocols are focused at the count in seconds that are spent loading the muscle. For instance, in the squat, continuously descending for 5 seconds before standing up. 

 

A BRIEF HISTORY OF ECCENTRIC TRAINING

 

Eccentric overload in training increases muscle hypertrophy, strength, and power. A researcher named Erling Asmussen first introduced eccentric training in 1953 as “excentric” training. This has been popularized in recent years. Training protocols such as Triphasic Training and Cal Dietz, and even French Contrast training, for instance. The eccentric portion of a lift slows down the lengthening of the muscle for a greater challence. Therefore, this helps lead to faster muscle repair, injury prevention, and greater muscle growth.

 

WHAT THE RESEARCH SAYS ABOUT ECCENTRIC TRAINING

A strong foundation of strength is important for force development. Above all, eccentric training can help increase overall strength. Researchers Higbie et al., studied concentric and eccentric training of the quadriceps muscle on strength, cross-sectional area and neural activation. They found that eccentric training increased strength in the eccentric muscle action to a larger degree than the concentric training. In other words, there was more efficiency in gaining strength while training eccentric than concentric. 

They also saw greater increases in hypertrophy from the eccentric training group than the concentric training group. Similarly, this means overall strength increases when focusing on the eccentric phase. However, it is hard to manage what you cannot measure, so Perch made it easy to measure eccentric metrics.

 

VBT AND ECCENTRIC TRAINING

 

With velocity based training, we want to see increases in power output. Researchers Douglas et al., did a systematic review of 40 studies. These studies researched the chronic effects of eccentric training. They found that eccentric training improves concentric muscle power. Eccentric training also improves the stretch shortening cycle performance. This was true with eccentric more than other training modalities. In addition, more effects of eccentric training in this review were muscle hypertrophy and strength.

 

However, the problem with eccentric training is if athletes hit their eccentric goals every rep. It is difficult to monitor every athlete in a weight room as they train eccentrically. With Perch, every rep eccentric load count and velocity will be recorded and stored. This ensures athletes get the desired adaptation from training. Ultimately, with better strategies to monitor training loads, athletes will continue to get bigger, stronger, and more powerful. This is true as both their seasons and training career progresses. In conclusion, train eccentrically, measure it, manage it!

 

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SOURCES:

  1. Douglas, J., Pearson, S., Ross, A., & McGuigan, M. (2017). Chronic adaptations to eccentric training: a systematic review. Sports Medicine, 47(5), 917.
  2. Higbie, E. J., Cureton, K. J., Warren, G. L. 3rd, & Prior, B. M. (1996). Effects of concentric and eccentric training on muscle strength, cross-sectional area, and neural activation. Journal of Applied Physiology (Bethesda, Md. : 1985), 81(5), 2173–81.

Weight room technology and all the data that is derived from it can be daunting to set up and to sift through. This can cause paralysis by analysis. Coaching time is valuable and limited so it is best to limit the amount of energy and time spent on setting up and evaluating velocity based training (VBT).

 

We have a few ways that can help you not get bogged down by velocity based training. In this post, we will go step by step to shed some light on simplifying the data collection process. Check out some ideas for avoiding paralysis by analysis with weight room technology here:

 

EQUIPMENT SET UP

Keeping setup and tear down of equipment minimal will only help streamline your program when it comes to velocity based training. Some traditional methods of applying VBT are a little bit more involved than they ought to be.

There are three main methods to measure bar speed: linear position transducers (LPTs), wearables or accelerometers, and camera based systems. The problem with most linear position transducers (LPT) is that they have to be placed in just the right place in order to get an accurate reading. That position then changes depending on the exercise performed. Changing the position of LPTs in a weight room setting can be a laborious task even with a large staff.

Using devices that only need to be installed once, or are on the user themselves makes it a lot easier to get moving. But accelerometers can also be cumbersome if every user needs one, or every barbell needs one. There is much greater room for error or missing reps if athletes aren’t compliant. And often athletes don’t want to wear yet another device.

Camera based systems, like Perch, stay mounted on your weight rack. There is no need to change the position of the unit, ever. With Perch, the camera is on a motor and can adjust positions as you adjust exercises. This means more time for coaches to focus on coaching and less on equipment set up and no take down at all (unless you want to).

setup, data analysis, paralysis by analysis

 

EXPORTING TRAINING DATA

Collecting data is great, but unless you are managing it, it is hard to make great use of it. There are still many VBT devices that have no way of exporting training session data out of the unit and storing them for coaches. Coaches have to monitor the velocities during the session and try to record the ones they see. Otherwise coaches can rely on athletes to record it, but compliance is not always 100%. This eats up precious time that could be spent coaching athletes.

Cloud based systems are ideal for managing data. With Perch, you can send all training session data to the cloud for storage. The cloud will store unlimited data for unlimited users. Coaches can then view or export the data to monitor trends longitudinally. This not only is great to have for current training sessions, but also for looking back to previous sessions to see improvement.

 

EVALUATING TRAINING DATA

Coaches know that making sense of many athletes training data after a session can take a long time. In order to streamline this, the process must be integrated. Choosing a VBT device that has the capability to take the training data from sessions, store it, and make it easy to understand and manipulate is pivotal. This makes evaluating and presenting the relevant data much easier than ever before. Perch can provides some in app visualizations of workload metrics for your athletes, but it also can export every data point associated with a training session. Picking a VBT device that can do this will make data collection and analysis incredible easy. And will help you avoid paralysis by analysis.

Often, the shear quantity of data can seem daunting as well. VBT is still somewhat new, so understanding velocity zones and some basic principles of programming with VBT can be helpful to start. But then simply collecting data, combining it with subjective data points (“how are you feeling today”) will help illustrate how helpful VBT can be. Just getting started can clarify a ton of mystery around data.

data analysis, paralysis by analysis

 

EXTRA HELP

Ultimately, weight room technology should work for coaches, not the other way around. Technology needs to be seamlessly integrated to be utilized most effectively. It needs to provide relevant data, not excess noise. And it needs to make that data easy to manipulate and visualize.

We always recommend evaluating different technology to find the best solution for you. With all this said, Perch is always here to help! We have specialists on staff to help you if you have a question, or are completely lost in the process. Check out our contact page for more information, and never hesitate to reach out!

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For as long as resistance training has been around, intuition has said that athletes need to lift until failure to see strength improvements. But what if that didn’t have to be the case? Enter: Velocity Drop Programming.

 

Research shows that velocity loss, or velocity drop, programming can result in equal or greater strength gains than performing a set to failure [4, 1, 2]. This holds true despite the decrease in reps and reported fatigue.

 

In this post we’ll explain what velocity loss programming is, the science behind it, and how devices like Perch can be used to implement.

WHAT IS VELOCITY DROP PROGRAMMING?

Velocity drop programming is simple. Programming a set based on a velocity loss threshold instead of a specific number of reps (or reps until failure). The athlete will record the mean velocity of their first rep, which is generally the fastest, and then perform reps until the velocity drops a specific percentage [1, 3]. 

If Perch shows an athlete’s mean velocity on rep 1 was 1 m/s, and a 20% velocity drop is prescribed, the athlete will perform maximal effort reps until the mean velocity drops below 0.8 m/s.

FATIGUE & THE SCIENCE BEHIND VELOCITY DROP PROGRAMMING

Velocity drop is an objective, non-invasive measure of fatigue levels. This makes it a great way to monitor an athlete throughout a session and account for daily fluctuations [3]. A study completed in 2011 found a nearly perfect correlation between mean propulsive velocity loss and increase in lactate levels, a known chemical measure of fatigue [3]. This correlation was present for both bench press and squat [3].

The difference in these two fatigue indicators is huge: Measuring lactate levels requires analyzing a small amount of blood drawn from a fingertip in a lactate analyzer before and after a set [3]. Measuring velocity loss simply requires looking at the data displayed instantly on Perch’s tablet.

As an athlete fatigues, their muscle fibers’ ability to generate force declines [3]. This leads to unintentional decreases in all of force, velocity, and power. If fatigue reaches a certain point, measured metabolically through lactate and ammonia levels, recovery time can become unnecessarily long [3, 1]. With velocity drop programming, fatigue levels and recovery time can be reduced. This is done through programming sets with low or moderate velocity loss. This will not reduce strength gains. Therefore, continuing to safely and efficiently progress an athlete without negatively impacting performance.

THRESHOLDS & THE SCIENCE BEHIND VELOCITY DROP PROGRAMMING

The proper velocity loss threshold for each exercise is still being determined, but two things that seem certain are that it depends on the desired training outcome and the exercise [4, 1, 3]. 

Larger velocity loss thresholds (about 30%-40%) will be closer to performing a set to failure and will result in greater muscle hypertrophy. This also may result in reduced velocity [4, 2]. Smaller velocity loss thresholds (about 10%-25%) results in greater strength and power, and less perceived fatigue [4, 1]. Velocity loss thresholds around 10% are most beneficial when competitions are close. This is when developing muscular power is the goal, or in sports that require greater kinematic outputs, such as throwing events [4].

These thresholds can also change based on the exercise. For example, a bench press has a lower minimum velocity than a squat, so the velocity loss threshold should be set to a greater percentage for a bench press [4].

 

RESEARCH & THE SCIENCE BEHIND VELOCITY DROP PROGRAMMING

A 2016 study found that a 20% velocity loss threshold training program resulted in similar squat strength gains and greater countermovement jump height improvements as an identical program that was performed with a 40% velocity loss threshold [1]. Overall, the 20% velocity loss threshold group performed nearly 40% less repetitions and 36% less “work” than the 40% velocity loss group, but saw similar or better results [1]. Basically, the group that did less improved more.

The research was further supported by a 2017 study. Researchers found that professional soccer players that trained with a 15% velocity loss program saw similar improvement in squat strength and endurance performance, along with greater improvements in countermovement jump height, than a group of players that trained with a 30% velocity loss program [2]. 

The two studies suggest that at worst, velocity loss programming with lower velocity loss thresholds results in similar strength gains with less work. At best, improvements are greater despite significantly less repetitions and fatigue.

IMPLEMENTING VELOCITY LOSS PROGRAMMING WITH PERCH

Perch is a great tool for implementing velocity loss programming! With a few simple steps and a Perch unit, it can be added to any program: 

  1. Using the information above, pick a velocity loss threshold
    • You can set velocity thresholds in the tablet app settings for each lift
    • If you choose to display these and use different colors for fast vs slow reps, you will get visual feedback rep after rep
  2. Perform one rep and look at the average velocity instantly output on the Perch tablet
  3. Perform reps until the velocity falls below the threshold

Have questions? Feel free to reach out!

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Keep checking back for more velocity based training content, tips, tricks, and tools. And don’t forget to follow us on Twitter , Instagram and Linkedin and like us on Facebook .

SOURCES

  1. Pareja-Blanco F, Rodríguez-Rosell D, Sánchez-Medina L, et al. Effects of velocity loss during resistance training on athletic performance, strength gains and muscle adaptations. Scandinavian Journal of Medicine & Science in Sports. 2016;27(7):724-735. doi:10.1111/sms.12678
  2. Pareja-Blanco F, Sánchez-Medina L, Suárez-Arrones L, González-Badillo JJ. Effects of Velocity Loss During Resistance Training on Performance in Professional Soccer Players. International Journal of Sports Physiology and Performance. 2017;12(4):512-519. doi:10.1123/ijspp.2016-0170
  3. SÁNCHEZ-MEDINA LUIS, GONZÁLEZ-BADILLO JUANJOSÉ. Velocity Loss as an Indicator of Neuromuscular Fatigue during Resistance Training. Medicine & Science in Sports & Exercise. 2011;43(9):1725-1734. doi:10.1249/mss.0b013e318213f880
  4. Weakley J, McLaren S, Ramirez-Lopez C, et al. Application of velocity loss thresholds during free-weight resistance training: Responses and reproducibility of perceptual, metabolic, and neuromuscular outcomes. Journal of Sports Sciences. 2019;38(5):477-485. doi:10.1080/02640414.2019.1706831

We’ve previously written about muscular anatomy and how muscles work to contract to perform a lift, but that still leaves a question unanswered. How do muscles actually grow and how do they adapt to make you stronger? And how does muscle growth and VBT interact?

 

To begin to explain this, there are 2 basic ways to get stronger: neural adaptations and muscular hypertrophy. 

NEURAL ADAPTATIONS AND MUSCLE GROWTH

Neural adaptations are responsible for the majority of strength gains at the beginning of a training program. It is also responsible for many of the changes seen with fast velocity training [5]. Neural adaptations are also responsible for some increases in force at slow and fast velocities [4]. 

The functional unit responsible for sending signals from a motor neuron to the muscle is called a motor unit. Each muscle has several motor units that can send a signal to all the muscle fibers it’s attached to. This signal instructs the muscle to contract. The more motor units recruited, the stronger the muscle contraction will be [4].

An untrained muscle won’t be able to activate all of a muscle’s motor units [2-3]. This is where training comes in, teaching your brain how to purposefully activate more motor neurons. This results in the recruitment of more motor units, and a stronger muscle contraction [1-3]. Training also teaches motor neurons to fire together and at a faster rate [1, 3]. When each motor neuron and subsequent motor unit fires in sync, the muscle is able to produce a stronger contraction.

Different muscle groups rely on firing rate and recruitment to different extents. Research has shown that smaller muscle groups like the muscles of the hand rely almost entirely on increasing firing rate to develop more force. Bigger muscles like the biceps and quadriceps use recruitment to increase force, while firing rate stays consistent until very high loads [2].

In a traditional percentage based program, these neural adaptations are the initial adaptations occurring with lighter loads of about 15-40% 1RM. Muscle growth and VBT corresponds to velocities greater than 1.3 m/s. 

THE SIZE PRINCIPLE AND MUSCLES 

Studies have begun to show fast velocity movements can cause motor units to defy the size principle [2]. The size principle states that smaller motor units are recruited before bigger ones. However, typically smaller motor units produce slower and weaker twitches. Defying the size principle allows muscles to go straight to the fast and strong big motor units, where powerful movements occur quicker.

 

 

 

The size principle tells us that neural adaptations also occur at slower velocities with high loads, the most sure way to teach the brain how to activate all motor units [4]. As loads increase to the 40-60% 1RM range and velocity decreases to about 0.75-1.3m/s, neural adaptations continue to teach motor units to fire more effectively. At this more effective stage, muscle hypertrophy occurs.

In a typical PBT, this range is where power develops – in VBT this range is broken down into the “Speed-Strength” and “Strength-Speed.” The combination of neural adaptations and hypertrophy helps move the entire force-velocity profile to the right, the resulting in a balanced, increased power production.

MUSCLE GROWTH AND HYPERTROPHY

Hypertrophy is the physical growth of muscle cells by developing thicker and more numerous myosin filaments. The increase in filament size and number leads to greater force and power [3]. Hypertrophy typically occurs at slower velocities with high loads closer to an athlete’s 1RM [2, 4, 5]. This is why the trait commonly known as “hypertrophy” in traditional percentage based training is trained at “Accelerative Strength” or at speeds between .5 and .75 m/s. VBT programs like Perch make it easy to find these velocity ranges.

When lifting a load greater than what the body is used to, the sarcolemma and the myofibrils in the muscle fibers are damaged [5]. In the next 24-48 hours, the damaged muscle fibers are repaired and hypertrophy can occur. To repair the damaged muscle fibers, protein synthesis must be greater than the rate of protein depletion [1, 5]. If this is not the case, the muscles can be destroyed rather than grow. This is why rest and diet are so important after a workout in addition to ensuring each training session accounts for stress and fatigue for each athlete [5].

The increased number and thickness of myofibrils leads to hypertrophy, but this doesn’t necessarily mean that the size of the muscle or limb is larger. Research shows that the density of myosin filament can increase as much as 50% before any increase in limb girth occurs. In a recent study, after training there was no increase in limb girth, but there was a 40% increase in strength due to the increased density, force per area, and potentially neural adaptations as mentioned above [3].

Hypertrophy takes much longer to occur than neural adaptations. This is why most strength gains at the beginning of a training program can be attributed to increased motor unit recruitment or firing rate, regardless of velocity and load [1]. Once hypertrophy occurs, it is responsible for the majority of force generation improvements. It will also be trained through a combination of increased load and velocities, to maximize force production.

CONCLUSION

Much is still unknown about how muscles adapt physically to different loads and velocities. Existing research suggests that pairing fast velocity movements with slower, heavier load movements can lead to the greatest strength and power improvements [6].

Incorporating both slow and fast maximal effort resistance training into a program can help muscle fibers convert from slower type I oxidative fibers to the stronger and faster type II muscle fibers [3, 6]. This combination helps athletes achieve increased velocity for muscle shortening and increased muscle fiber strength, ultimately improving power and moves the force-velocity curve to the right [3, 6].

Measuring this throughout training will help to achieve these strength and power goals. At faster velocities, and consequently lighter loads, most strength gains will be due to neural adaptations. Closer to a 1RM, most improvements will be due to hypertrophy, or muscle growth. In the middle velocities, there will be a combination of neural adaptations and muscle hypertrophy. Muscle growth and VBT are inseparable as VBT allows for the tracking of neural adaptations leading to hypertrophy, and Perch can help coaches and athletes program workouts at proper velocities to see strength development occur at the neurological and hypertrophic levels.

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SOURCES

  1. Andrews MAW. How does exercise make your muscles stronger? Scientific American. https://www.scientificamerican.com/article/how-does-exercise-make-yo/#:~:text=Muscle%20cells%20subjected%20to%20regular,to%20the%20stress%20of%20training.&text=Because%20there%20are%20more%20potential,muscle%20can%20exhibit%20greater%20strength. Published October 27, 2003. Accessed May 19, 2021.
  2. Behm DG, Sale DG. Velocity Specificity of Resistance Training. Sports Medicine. 1993;15(6):374-388. doi:10.2165/00007256-199315060-00003
  3. Jones DA, Rutherford OM, Parker DF. PHYSIOLOGICAL CHANGES IN SKELETAL MUSCLE AS A RESULT OF STRENGTH TRAINING. Quarterly Journal of Experimental Physiology. 1989;74(3):233-256. doi:10.1113/expphysiol.1989.sp003268
  4. Kawamori N, Haff GG. The Optimal Training Load for the Development of Muscular Power. Journal of Strength and Conditioning Research. 2004;18(3):675-684. doi:10.1519/00124278-200408000-00051
  5. Leyva J. How Do Muscles Grow? The Science of Muscle Growth. BuiltLean. https://www.builtlean.com/muscles-grow/. Published December 31, 2020. Accessed May 19, 2021.
  6. Wilson JM, Loenneke JP, Jo E, Wilson GJ, Zourdos MC, Kim J-S. The Effects of Endurance, Strength, and Power Training on Muscle Fiber Type Shifting. Journal of Strength and Conditioning Research. 2012;26(6):1724-1729. doi:10.1519/jsc.0b013e318234eb6f 
  7. Baechle, T., Earle, R., & National Strength & Conditioning Association (U.S.). (2008). Essentials of strength training and conditioning (3rd ed.). Champaign, IL: Human Kinetics.

If you are a new reader to this blog space, every few months we like to break down some of the best and/or most recent velocity based training research. Sometimes it is directly related to VBT, sometimes it is broadly related to strength & conditioning. Either way, we provide the citation, a brief synopsis of methods and results, and leave the rest up to you. This week we wanted to bring you two recently released research articles closely related to velocity based training. Without further ado, here is our 5th research review:

STUDY 1

COMPARISON OF INDIVIDUAL AND GROUP-BASED LOAD-VELOCITY PROFILING AS A MEANS TO DICTATE TRAINING LOAD OVER A 6-WEEK STRENGTH AND POWER INTERVENTION

Researchers Dorrell, Moore, and Gee recruited 19 trained male subjects (23.6 ± 3.7 years) and randomly assigned them to either the Individual Load Velocity Profile (ILVP) group or Group Load Velocity Profile (GLVP) group. The purpose of the study was to determine whether improvements in performance were greater in the individual load velocity profiles or group load velocity profiles. Subjects were all tested in the back squat one repetition maximum (1RM), load-velocity profiling (LVP), countermovement (CMJ), static-squat (SSJ) and standing broad (SBJ) jump tests before and after 6 weeks of resistance training. Upon retesting of all subjects, results indicated that jump performance significantly increased for the ILVP group (p < 0.01; CMJ: 6.6%; SSJ: 4.6%; SBJ: 6.7%), with only CMJ and SSJ improving for the GLVP group (p < 0.05; 4.3%). The back squat 1RM increased significantly for both the ILVP (p < 0.01; 9.7%) and GLVP groups (p < 0.01; 7.2%). While both interventions yielded positive results, researchers suggested the findings proved that the individualized approach may lead to greater improvements.

Dorrell, H. F., Moore, J. M., & Gee, T. I. (2020). Comparison of individual and group-based load-velocity profiling as a means to dictate training load over a 6-week strength and power intervention. Journal of Sports Sciences.

velocity based training research review 5 blog post

STUDY 2

GUIDELINES AND RESOURCES FOR PRESCRIBING LOAD USING VELOCITY BASED TRAINING. IUSCA JOURNAL

Researchers Moore & Dorrell utilized multitudes of existing research to develop guidelines for prescribing load through the use of velocity based training. When prescribing load, coaches often have no means of taking velocity into account, and adapting training loads for the varying fluctuations in physiological conditions athletes can be in day to day. The researchers developed an app that can assist in prescription (linked below). While this was primarily a review of existing research, the investigators highlighted the importance of load/velocity profiles: “LVPs have been shown to remain unchanged despite significant increases in absolute strength and have therefore been theorised as a potential auto-regulatory approach for prescribing training load.” This research largely cited the first study we reviewed in this article.

Load/Velocity Calculator Here

Moore, J., & Dorrell, H. (2020). Guidelines and Resources for Prescribing Load using Velocity Based Training. IUSCA Journal, 1(1). Retrieved from http://journal.iusca.org/index.php/Journal/article/view/4

Also check out our Perch post on Understanding Force/Velocity Profiles

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Returning from injury can be a scary time for any athlete. Often, sports injuries are single-sided. For today’s post, we wanted to talk about using the data VBT provides as an additional piece of information in a return-to-play protocol. For coaches and ATs and even PT professionals working in rehab settings, VBT can provide helpful data as it pertains to overall athlete health and wellness. To help shed some light, we will use the all-too-common ACL tear as an example.

SOME ACL STATISTICS

According to the Centers for Disease Control and Prevention (CDC) there are approximately 250,000 ACL ruptures each year in the United States alone, accounting for upwards of $2 Billion in health care costs [1]. Despite return to play likelihood sitting at 81%, the risk of reinjury for the ipsilateral side sits around 5.8%, while the contralateral side sits at 11.8% [2]. According to Brophy et al., after 7 years only 36% of the athletes participating in their study were still playing compared to the 72% that had returned to play following their ACL injuries [4]. This decline was due in part to reinjury and additional surgeries [4].

RETURN TO PLAY AND VBT

While the autoregulatory component of VBT and adjusting training contingent on an athletes’ readiness and fatigue statuses can help prevent overtraining and potential associated injuries, VBT can also play a critical role in the return-to-play (RTP) protocol.

Typically the RTP protocol is a series of progressive exercises that slowly bring an athlete back to full playing level. The problem is that athletes and athlete bodies are intelligent and can often find a way to compensate that may be imperceptible to the coach’s eye. This is when something like a force plate can play a critical role in identifying when a compensatory pattern is emerging. While force plates can identify it, they may not be able to fix the issue unless the athlete is actively coached up, which may or may not be feasible depending on the setting.

Identifying differences between right and left sides can help shed light on any compensatory patterns post ACL reconstruction on the return-to-play road.
Identifying differences between right and left sides can help shed light on any compensatory patterns post ACL reconstruction on the return-to-play road.

What VBT allows for is to see the data from a power production and velocity perspective, from one side compared to the other. With devices like Perch, a right and left side split squat can be differentiated on the output screen. Additionally, because of these immediate and objective outputs, the athlete can not only see when one side is lagging behind, but can feel when it is producing the proper velocity and power and have that feeling confirmed with live data.

The live output and set summary screen on the Perch tablet app can shed light on whether one side is weaker than another and what needs improving.
The live output and set summary screen on the Perch tablet app can shed light on whether one side is weaker than another and what needs improving.

CONCLUSION

With ACL injury rates as high as they are, and as long as reinjury rates still exist, we know practitioners and athletes alike can still find and use more tools to help get back on the field and stay there. VBT may not solve all ACL return to play or reinjury issues, but it is another tool in the tool belt. Additionally, VBT and the data it provides can allow practitioners to make further assumptions about various injuries and help athletes develop the armour they need to play longer.

OTHER RELEVANT POSTS!

Check out our Return To Play from Covid-19 series!

Curious about how different populations can utilize VBT? Check out our VBT for specific populations series!

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Keep checking back for more velocity based training content, tips, tricks, and tools. And don’t forget to follow us on Twitter , Instagram and Linkedin and like us on Facebook .

SOURCES:

  1. CDC – Injury – ICRCs – CE001495. (2010, July 13). Retrieved January 20, 2020, from https://www.cdc.gov/injury/erpo/icrc/2009/1-R49-CE001495-01.html
  2. Sepúlveda, F., Sánchez, L., Amy, E., & Micheo, W. (2017). Anterior cruciate ligament injury: Return to play, function and long-term considerations. Current Sports Medicine Reports.
  3. Joseph, A. M., Collins, C. L., Henke, N. M., Yard, E. E., Fields, S. K., & Comstock, R. D. (2013). A multisport epidemiologic comparison of anterior cruciate ligament injuries in high school athletics. Journal of Athletic Training.
  4. Brophy, R. H., Schmitz, L., Wright, R. W., Dunn, W. R., Parker, R. D., Andrish, J. T., … Spindler, K. P. (2012). Return to play and future ACL injury risk after ACL reconstruction in soccer athletes from the multicenter orthopaedic outcomes network (MOON) group. American Journal of Sports Medicine.

Most Velocity Based Training devices have the ability to output power as an additional metric alongside velocity. If you refer back to our VBT Dictionary Post you’ll see the difference between force, power and velocity. While these are all very different concepts, they can all uniquely help describe various aspects of athleticism. Depending on the time of year, needs analysis of the sport, and the athlete in question, measuring and tracking power instead of velocity or vice versa is an important consideration.

In this post, we wanted to discuss power and velocity, and what instances a coach may want to consider tracking one over the other. Luckily, with Perch, power and velocity are recorded for every single rep of every single set and stored in the cloud for post-workout analysis, so you don’t necessarily need to choose. The live output is the only time you will only see one metric, and for that tracking power vs velocity is a consideration.

SOME GROUNDWORK

If you refer back to one of our earliest blog posts about the VBT crash course VBT crash course. you will see the force/velocity curve, we have also included this below

In this picture, you can see that the typical percentage zone of Peak Power lies within 30-80% of an individual’s 1RM [1]. We know this 1RM fluctuates and in order to accurately stay within that percentage, objective feedback is necessary [2]. It is also fairly easy to see that the peak power range covers three unique VBT zones or traits, Speed-Strength (30-60% 1RM) and Strength-Speed (30-60% 1RM) and Accelerative Strength (60-80% 1RM). We also know that power is described on a bell curve, as seen below:

When we talk about improving power, we are talking about the ability to improve the amount of work performed over a shorter period of time. Or as it pertains to VBT, the force produced at specific velocity. If your primary focus is to improve power, and you are less concerned with monitoring fatigue or the autoregulatory component of VBT, making power your primary feedback would be ideal.

WHEN TO TRACK VELOCITY

We have talked extensively about when and why to track velocity. As a quick refresher, monitoring velocity to adhere to specific traits associated with velocity zones, to monitor fatigue, to assess readiness, and to promote and teach intent are all great uses of velocity outputs. Additionally, velocity is excellent to use at maximum and minimum values in order to closely monitor speeds, it is also very helpful to use in season to continually adapt to athletes’ individual needs on the fly.

But what if you don’t necessarily need to track all of these things in live time? What if you want to simplify and teach your athletes to compete, to work hard, and prove it?

WHEN TO TRACK POWER

Power is a great primary metric to track when you just want maximal output from your athletes. When you’re focusing on training within the “Peak-Power” zone (or from speed-strength to strength-speed) of 30-80% 1RM and aren’t primarily concerned with fatigue status etc. An athletes’ off-season or preseason may be the optimal time to be chiefly focused on Power outputs over velocities. This is the time when they aren’t performing on the field, they have more time to be focused on the weight room and have a less variable schedule as it relates to a competition schedule and travel time. If you are focused on them producing power, proving it to themselves and their teammates with live outputs and on the leaderboard, and less with regulating loads, prioritizing power outputs for a training cycle periodically is a great idea.

CONCLUSION

This post was meant to serve as a guideline with some additional insight as to when a coach could use power instead of velocity, and how power and velocity monitoring can be utilized. There is no right or wrong answer, as it will depend on your preferences, your athletes, and your program. Power outputs can complete a picture and help describe an athlete’s ability with greater clarity. Regardless, when using Perch you will only have to decide what is immediately output, as every metric will be recorded and stored for your analysis and convenience.

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Keep checking back for more velocity based training content, tips, tricks, and tools. And don’t forget to follow us on Twitter , Instagram and Linkedin and like us on Facebook .

SOURCES:

  1. Bompa, T., & Buzzichelli, C. (2015). Periodization training for sports (Third ed.). Champaign: Human Kinetics.
  2. Jovanovic M, and Flanagan EP. (2014). Researched applications of velocity based strength training. J. Aust. Strength Cond. 22(2)58-69.
  3. Cronin, J.B., McNair, P.J., & Marshall, R.N. (2003). Force-velocity analysis of strength training techniques and load: Implications for training strategy and research, Journal of Strength and Conditioning Research, 17(1), pp.148-155.
  4. Cronin, J, McNair, PJ, and Marshall, RN. (2001). Developing explosive power: A comparison of technique and training. J Sci Med Sport 4: 59–70.
  5. Maffiuletti, N. A., Aagaard, P., Blazevich, A. J., Folland, J., Tillin, N., & Duchateau, J. (2016). Rate of force development: physiological and methodological considerations. European Journal of Applied Physiology.
  6. Mann, B., Kazadi, K., Pirrung, E., & Jensen, J. (2016). Developing explosive athletes: Use of velocity based training in athletes. Muskegon Heights, MI: Ultimate Athlete Concepts.
  7. Randell, AD, Cronin, JB, Keogh, JWL,Gill, ND, and Pedersen, MC. Effect of instantaneous performance feedback during 6 weeks of velocity-based resistance training on sport-specific performance tests. J Strength Cond Res 25(1): 87–93, 2011.