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Category Archives: Basics of VBT

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 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. 




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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  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.<675:totlft>;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.
  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. 

What goes up, must come down! This is true in not only gravity, but in most lifts as well. Eccentric training is critical for athlete and force development. The eccentric – or the lengthening – muscle action is arguably the most important part of a muscular contraction to indicate resilience to injury and overall max strength.


When we look at eccentric training protocols, we are generally looking at the count, or how many seconds are spent eccentric loading the muscle. An example of this would be in the squat, continuously descending for 5 seconds before standing up. 




Eccentric overload in training has been shown to increase 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 with training protocols such as Triphasic Training and Cal Dietz, and even French Contrast training. The eccentric portion of a lift slows down the lengthening of the muscle to challenge the muscles more. This helps lead to faster muscle repair, injury prevention, and greater muscle growth.



A strong foundation of strength is important for force development. Eccentric training has been shown to 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 essence: 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.

This means that overall strength increases when focusing on the eccentric phase. And as you know, it is hard to manage what you cannot measure, so Perch made it easy to measure eccentric metrics.




When we look at velocity based training, we want to see increases in power output. Researchers Douglas et al., did a systematic review of 40 studies researching the chronic effects of eccentric training. They found that eccentric training improves concentric muscle power and the stretch shortening cycle performance more than other training modalities. Muscle hypertrophy and strength were also primary effects of eccentric training in this review.


The only problem with this training, especially in training teams or groups of athletes is if they are hitting their eccentric goals with every rep in the workout. It is difficult to monitor every athlete in a weight room as they go through eccentric training. With Perch, every rep eccentric load count and velocity will be recorded and stored to make sure your athletes get the adaptation you desire from your training. With better strategies to monitor training loads, athletes will continue to get bigger, stronger, and more powerful as their season and training career progresses.



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  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:



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



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.



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



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.


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.


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.


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].



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.


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!


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 .


  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 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. 


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.


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.


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.


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 .


  1. Andrews MAW. How does exercise make your muscles stronger? Scientific American.,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. 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:



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



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

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


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 .

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.


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].


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.


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.


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!


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 .


  1. CDC – Injury – ICRCs – CE001495. (2010, July 13). Retrieved January 20, 2020, from
  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.


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.


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?


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.


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.


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 .


  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.

This week we wanted to define some key phrases, buzzwords, and practices used with Velocity Based Training. Often and without even realizing it, coaches and athletes alike can misuse VBT terminology associated with strength training, so we wanted to provide a quick at-a-glance look at some key definitions. We’ll also provide some equations to hopefully shed more light on some VBT terminology. All citations can be found at the bottom. Without further ado:


Measure of how quickly an object moves. The change in the position of an object divided by the time it takes. Velocity is a vector quantity and therefore has direction. Velocity is measured in m/s.

Velocity = (final position) – (initial position) / time

Velocity = displacement / time


The rate at which work is done. Measured in Watts (W).

Power = work / time

Power = force x displacement / time

Power = force x velocity


The mass of an object multiplied by its acceleration, it has both magnitude and direction. Measured in Newtons (N)

F = mass x acceleration


Distance traveled per unit of time; how fast an object moves regardless of direction

Speed = distance / time


The training methodology of utilizing a piece of technology to track the movement speed in a given direction of an exercise


The training methodology of utilizing various percentages of an individual’s one repetition maximum (1RM) in order to determine the weight used in each training session.


One repetition maximum; the maximum amount of weight a person can lift for a single repetition of a given exercise.


A form of periodization that adjusts to the individual athlete’s adaptations on a day-to-day or week-to-week basis


The average of all numbers; a calculated central value defined by adding up all numbers and divided by how many numbers there are

m = sum of terms / number of terms


The maximum or highest value in a wave (upward motion)


In weightlifting, movement that lengthens a muscle while concurrent contraction occurs. Typically the lowering portion of a movement.


In weightlifting, movement that shortens a muscle while concurrent contraction occurs. Typically the raising portion of a movement.


In weightlifting, a static muscular contraction without any visible movement or change in the joint angle.


The amount of weight on the bar


In weightlifting, failure to maintain the required or expected force due to muscular exhaustion. The inability of a muscle to continue to contract.


Specifically for VBT, the “intent” to perform a lift with maximum concentric acceleration. Alternatively, a vigorous or determined attempt.


In weightlifting, the difficulty of an exercise. In some circles, “how heavy” defines intensity. In physics, power transferred per unit area (W/m2)


In weightlifting, the number of repetitions of a given exercise or training session


The effort put forth of an individual on a given rep or set


How often an individual performs something (a rep, a set, a workout etc)


Usually the velocity associated with the last successful rep in a maximal effort set, this will then serve as the cutoff velocity for maximal efforts in the future.


The average velocity from the start of the concentric phase until the end of the movement where the acceleration is greater than the acceleration due to gravity (all data points in the concentric movement above where acceleration of barbell is greater than -9.81m/s and averaged)


Want to see VBT terminology in action? Check out our VBT research review series!

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

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


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 .


  1. Baechle, T., Earle, R., & National Strength & Conditioning Association (U.S.). (2008). Essentials of strength training and conditioning (3rd ed.). Champaign, IL: Human Kinetics.
  3. Science, R. S. of. (2017, March 28). Velocity Based Training for Maximal Strength. Retrieved from
  4. Thomas, D. (2015). The dictionary of physical geography (4th ed.) [4th]. Wiley-Blackwell. (2015). Retrieved December 17, 2019, Velocity Based Training. (2019, December 16). Retrieved from

One of the biggest criticisms of Velocity Based Training is that you will never move a barbell faster than you will move your body when at a full sprint. This is absolutely true. VBT is not about trying to sprint faster, it is about optimizing bar speed while training for specific traits and adaptations. Enhancing those specific traits could ultimately lead an individual to improve upon their sprinting speed, but improving sprint speed is not the sole purpose of using VBT in the weight room.

Weight room training can inform speed on the field, all the while bulletproofing tendons, ligaments, and muscles through progressive overload and periodization. In no way is VBT a replacement for true speed and sprint work as part of training or conditioning. It is simply about optimizing bar speed with objective outputs to train with specificity for a desired trait and subsequent adaptation.


Legendary speed coach, Charlie Francis (along with plenty of other sprint coaches) has repeatedly said to get faster, you must train faster [1]. Faster for Francis means training at speed that are 90-95% of max-speed, this same principle is true for JB Morin [2-5]. In the weight room, we can replace the word “max-speed” with “max-effort.” Regardless of the trait an individual is training for, provided their effort or intentionality lies within that 90-100% range, chances of adaptation are greater.

In 2009, Usain Bolt set the World Record in the 100m with a top speed of about 12.40 m/s, in that same race, he averaged about 11 m/s over the duration of the 100m [6]. Now, the layman or perhaps just accomplished high school athlete is going to be closer to 8 m/s. In the weight room, explosive movements (with the exception of a jump squat) are hard pressed to exceed 3 m/s.

Usain Bolt, 100m World Record holder courtesy of Richard Giles [8]
Usain Bolt, 100m World Record holder courtesy of Richard Giles [8]

Will you ever be able to move a barbell faster than you sprint? No. Does that mean you shouldn’t try to optimize bar speed? Heck no! VBT gives us valuable information regarding fatigue status and readiness, it also provides immediate and objective feedback, much like timed sprints, that will inform and enhance performance in live time. The principles behind desiring to time sprints to improve foot speed are the same as providing a speed metric to a barbell. Ensuring 90-100% effort and providing a metric that backs it up allows athletes to train with precision and to the best of their ability, time and again.


Moreover, those same principles behind timing sprints and VBT help enhance performance by the simple gamification of the activity.

Gamify = To apply typical elements of game playing to an activity (e.g. point scoring, competition etc).

VBT, similar to timing sprints, helps create a competitive environment, the live outputs being the points. All of this has been shown to enhance skill acquisition [7] and ultimately yield improvements to the individual.


Velocity Based Training in a weight room will never yield numbers that rival velocities in a sprint. This is true. That, however, is not the goal of VBT. Optimizing bar speed, enhancing overall effort to acquire the trait, monitoring load, and creating strong and capable athletes in a weight room setting is the goal of VBT. True sprint speed should be acquired in a sprint training setting. Bar speed in a weight training setting.


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

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


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


  1. Francis, C. (1997). Training for speed. Canberra, A.C.T., Australia: Faccioni Speed & Conditioning Consultants.
  2. Morin, J. B., & Samozino, P. (2016). Interpreting power-force-velocity profiles for individualized and specific training. International Journal of Sports Physiology and Performance.
  3. Samozino, P., Rejc, E., Di Prampero, P. E., Belli, A., & Morin, J. B. (2012). Optimal force-velocity profile in ballistic movements-Altius: Citius or Fortius? Medicine and Science in Sports and Exercise.
  4. Samozino, P., Rabita, G., Dorel, S., Slawinski, J., Peyrot, N., Saez de Villarreal, E., & Morin, J. B. (2016). A simple method for measuring power, force, velocity properties, and mechanical effectiveness in sprint running. Scandinavian Journal of Medicine and Science in Sports, 26(6), 648–658.
  5. Jiménez-Reyes, P., Samozino, P., Brughelli, M., & Morin, J. B. (2017). Effectiveness of an individualized training based on force-velocity profiling during jumping. Frontiers in Physiology.
  6. World Athletics |. (n.d.). Retrieved December 10, 2019, from
  7. Wulf, G., Shea, C., & Lewthwaite, R. (2010). Motor skill learning and performance: A review of influential factors. Medical Education, 44(1), 75–84.
  8. Usain Bolt Photo By Richard Giles, CC BY-SA 2.0,