Power Unveiled
The Science, Art, and Impact on Performance and Rehabilitation
If you’ve been reading this substack, this post might seem a little different. This platform is intended to be for anyone who is interested in human performance – physical therapists, strength coaches, athletic trainers, chiropractors, sport coaches, sports medicine physicians, students, and fitness enthusiasts. This post is a bit more dense than previous posts, but something all the above-mentioned disciplines will find intriguing. It is inspired by something that has been a topic of internal discussion with my team at Train Recover Move and some strength coaches at the University of Arkansas athletics. I hope to get your brain thinking about a word that is thrown around a lot in athletics; a word that is a little more complicated than you might think… power.
In the world of Olympic sports, the mantra 'Citius, Altius, Fortius,' meaning 'Faster, Higher, Stronger,' encapsulates the ultimate goals of competition. This philosophy is deeply ingrained in the pursuit of power and performance excellence. In this post, we'll delve into the intricacies of power training, exploring key components and principles that contribute to achieving optimal athletic prowess, and how these fit in the world of rehabilitation.
The Foundation of Power
The journey toward optimal power begins with a well-rounded foundation. Before athletes can develop maximal power through specific training, they must develop a foundation of strength, cross-sectional area, tendon stiffness, and more. This foundation sets the stage for the subsequent principles of power training. Power is defined as force X velocity, with force being the weight of the object being moved, and velocity being the speed at which the object is moved. Force and velocity have an inverse relationship as shown in the force-velocity curve. As force (external load) goes up, velocity goes down and vise versa. The highest power is that where both force and velocity are optimized.
It is well known in rehabilitation that regaining strength is of utmost importance. There are multiple tests used throughout the rehabilitation process to gauge strength. This is typically expressed as a Limb Symmetry Index, which gives a percent of how the affected extremity compares to the unaffected extremity. Tests such as force gauge dynamometry and biodex isokinetic testing are commonly used by rehabilitation professionals. However, strength is just one small component of the physical attributes needed to successfully return to sport. The ability of a muscle to generate maximal force and the ability of a muscle to generate force quickly are very different. Rehabilitation professionals are becoming more aware of the dire need for athletes to regain full strength. Could power be a missing component? Could an emphasis on regaining power ensure a more successful return to sport? Let’s explore power training and the impact it could have on rehabilitation.
5 Key Components for Power Training
1. Maximal Intent
Maximal intent, the first key component of power training, emphasizes the athlete's effort during exercises. Adaptations are determined by the athlete's exertion, and it's crucial to complete movements with the highest velocity possible. The athlete must be moving with 100% effort every single repetition. Velocity monitoring systems such as a Tendo unit provide immediate feedback. This technology can further increase an athletes’ motivation and understanding of what a “maximal effort” feels like. Only when athletes are executing all exercises with maximal intent will the remaining 4 principles be capable of improving power production.
2. Achieving the Highest Readiness
Preparing the body for power training involves more than a standard warm-up. Post-Activation Potentiation (PAP) emerges as a powerful method, enhancing an athlete's ability to generate force with heavier loads and a low number of repetitions. PAP influences the nervous system and local muscles. It lays the groundwork for optimized power output by recruiting more motor units to perform the work. By priming or activating more motor units, the power-based movement that follows can be performed faster with more force since more motor units have been accessed. These parameters can be met with short range of motion (ROM) movements or isometric exercises, with focus placed on maximal intent and effort. For example:
2-3 sets x 1-3 repetitions at 85-100% of the 1 RM with 1-2 minutes rest for short ROM movements
2-3 sets x 5-7 seconds at max effort with 1-2 minutes rest for isometrics
Here is an example of where PAP fits in a warm-up based on the RAMP principle. Check out Enhancing Athletic Potential for a full explanation of the RAMP principle.
Raise body temperature: jog with arm circles, skipping for height
Activate: see the article Is Stretching a Waste of Time? for an explanation of stability drills
Mobilize: see the article Is Stretching a Waste of Time? for an explanation of mobility drills
Potentiate:
o High pin split squats for 2-3 sets x 1-3 repetitions at 85-100% of the 1RM
o Trap bar deadlift isometric pin press for 2-3 sets x 5-7 seconds at max effort
3. Optimal Load Dosage
Selecting the right training loads is a critical aspect of power development. Training loads must be selected that are appropriate for the specific desired adaptation. Strength-speed, speed-strength, and speed training each play distinct roles in optimizing power across the force-velocity curve. However, it is difficult for any “skill” specific movement to be trained in the weight room. Instead, the weight room is typically geared toward making the athletes physiology more specific or compatible with the sport.
For example:
increase cross-sectional area of a muscle → increase force producing capabilities → increase performance
See Squats and Sprints Part II: Rethinking Specificity from the Art of Training for a more in-depth explanation of the physiological adaptations acquired in the weight room.
Specificity in the weight room is more than just increasing a muscles size. Specificity is also related to the speed at which the movement is done. It has been shown that adaptations are velocity specific. Meaning that strength gains are specific to the velocity at which training was done. Therefore, hitting consistently heavy squats at .4m/s won’t do much to improve power at 1.7m/s. This is hard to apply because sport movements are completed at such high velocities. However, power can be easily targeted in the weight room and may bring about more “sport specific” physiological adaptations that are associated with an increase in sport performance.
With power depending on force and velocity, each must be trained in an individual manner, with each receiving stress at certain times throughout training. Increasing strength can raise the ceiling for a while, but when trying to focus or peak a certain sub-max strength quality, such as power, it needs to be specifically targeted. By attacking each of these aspects, power can be improved throughout the entirety of the force-velocity curve. Let’s break down 3 big categories of power training over the force-velocity curve.
Strength-speed
Strength is the priority, so higher loads are implemented (NOT max strength work) while still applying maximal intent (moving the bar as fast as possible). Adaptations are more aimed at the force aspect of power = force x velocity.
Example: squatting at 65-70% 1RM, moving the bar at moderate velocity
Speed-strength
Speed is the priority, so moderate / low loads are implemented. Adaptations are more aimed at the velocity aspect of power = force x velocity.
Example: squatting at 45-55% 1RM, moving the bar at higher velocity
Speed
Speed is the only priority, so low loads are implemented. Adaptations are entirely aimed at the velocity aspect of power = force x velocity. It is most transferrable to sport, but you still must train all other aspects to see maximal transfer.
Example: squat jump at 0-15% 1RM
The “sweet spot” for optimal power development is 60% load at 0.9m/s. The graph below shows the force-velocity curve with corresponding external loads (percentages of 1RM) and velocities (meters / second).
4. Maintain Velocity
Maintaining velocity is paramount for power training. The external load (force) remains constant, and power is determined by the velocity at which it is moved. Quality repetitions with high velocity are essential. Power training requires low repetitions with high velocity. It is important to note that improving work capacity is completely different than improving power output. Work capacity refers to the ability to continue to push to the brink of exhaustion. As volume increases and rest time decreases, the ability to produce the same maximal velocity is reduced.
Having bar speed measures available helps ensure that velocity is sustained throughout the training session. Once the specific goal is determined (strength-speed, speed-strength, speed), velocity-based training (VBT) can be used by setting a target velocity on a device such as a Tendo unit. The Tendo unit provides immediate feedback on if the athlete hit the target velocity. The Tendo unit provides measures of peak velocity and average velocity, with average velocity being most appropriately utilized for non-ballistic movements, and peak velocity being a better predictor of ballistic movements. Non-ballistic movements are defined as when the bar, or athlete, does not become a projectile. There is both an acceleration and deceleration phase, and complete stoppage i.e., barbell squat and bench press. Ballistic movements are defined as when the athlete or bar does become a projectile and there is no deceleration phase i.e., a jump or throw. Olympic movements (clean and jerk, snatch) are categorized as ballistic exercises since the bar itself does become a projectile and is accelerated throughout its entire range of motion. Therefore, peak velocity is the appropriate measure for Olympic movements.
5. Minimize Fatigue
To maximize power adaptations, minimizing fatigue is crucial. Power training is most effective when performed at higher power outputs. If an athlete starts a training session in a fatigued state, either metabolic or neurologic fatigue, the desired power training stimulus might not be achieved. Monitoring fatigue through various methods, including vertical jump height, bar velocity, and wearable technology, allows coaches, rehabilitation professionals, and athletes to tailor training sessions, providing optimal stress for individual athletes.
“A performance coach is ultimately a stress manager and must realize that balance is crucial in order for optimal performance to be achieved.” The performance coach isn’t the only person responsible for managing an athlete’s stress – stress comes from sport practice, weightlifting, rehabilitation, and daily life stressors. Everyone on the sports medicine team must consider the stress being placed on an athlete. A simple way to view the stress being applied in training is to consider training on a continuum. If stress is applied at an extreme amount with limited recovery, the athlete will be unable to cope with excessive levels of stress and begin to respond poorly. At the opposite end, if not enough stress is applied during training, the desired adaptations will not occur, and optimal performance will never be achieved. Too much or too little stress will hinder the improvement of power production. This is why managing and balancing stress is a crucial aspect in working with athletes. The ability to minimize and monitor fatigue during training is vital to maximizing power adaptations. If fatigue accumulates and the athlete cannot achieve the highest velocities, power is reduced.
Other Power Considerations
Rate of Force Absorption (RFA)
The ability to rapidly absorb force, or the eccentric RFD, is both critical for optimal power production and injury reduction. Rate of force absorption (RFA) is the amount of force and speed an athlete can safely and rapidly decelerate. Explosive changes of direction require rapid deceleration prior to accelerating in the new direction. Ultimately, the athlete that can “throw on their brakes” the fastest (eccentric), complete the short isometric phase, and then re accelerate (concentric) the quickest will demonstrate the most explosive ability. RFA is not just important for being quick and explosive, it is important for safety and reduction of injury. Athletics require high velocity and high force movements over short periods of time. If the athletes’ body can’t handle these forces, they increase the risk for injury with incorrect execution.
Rate of Force Development (RFD)
Power production and rate of force development (RFD) go hand in hand. It is the rate at which force is developed, rather than the absolute amount of force, which leads to the greatest change in performance. The reason for placing importance on RFD is due to the limited time available for athletes to deliver force in their competition movements. The time available for force development in athletic movements is much smaller than the time needed for the body to produce maximal force. For example, the ground contact time in max velocity sprinting is typically between 0.08 and 0.12 seconds, and the time it takes to produce maximal force is between 0.3-0.4 seconds. The ability to produce force rapidly becomes more important than maximal force production. RFD can be measured on a Tendo unit by looking at “Partial Average Power.”
One way to improve RFD is through accelerated methods. If velocity is the goal, training must happen as close to maximum velocity as possible. Maximal velocity occurs when force is near zero. Without assistance, it is nearly impossible to achieve an external force of zero because of body weight. With assistance, an athlete can achieve movement velocities against loads that are less than their body weight, allowing the athlete to train with closer to maximal velocities. If the load is reduced by 20%, this can lead to significant changes in velocity when maximal intent is applied. Remember, adaptations happen at the specific speeds that they are trained. Some examples of accelerated methods are band assisted vertical jumps and assisted speed training.
Another way to improve RFD is by varying the range of motion. Greater knee flexion and a longer ground contact time may result in greater emphasis on the contractile force of the knee extensors. While a shorter ground contact time and smaller range of motion may rely more on the stretch shortening cycle and elastic qualities. These subtle differences will change the training stimulus.
Performance Team
In conclusion, the pursuit of 'Citius, Altius, Fortius' is intricately tied to the principles of power training. Power, the most desired positive physiological adaptation in athletic movements, is developed through maximal intent, readiness, optimal load dosage, velocity maintenance, and fatigue minimization. Clearly, coaches play a pivotal role in implementing exercises that elicit the desired responses, optimizing mental and physical states. If power is lost after an injury, should rehabilitation not consider this vital adaptation when to returning an athlete to sport? By embracing these principles and considerations, athletes, coaches, and rehabilitation professionals alike can unlock the true potential of 'Citius, Altius, Fortius' in the pursuit of athletic excellence.
Here is an example of how to utilize and progress Velocity Based Training using a Tendo unit velocity monitoring system with a trap bar deadlift exercise. Let’s see the 5 key components I discussed above in action!
Educate your athlete that they must give 100% effort and try to move as fast as possible on every repetition
Achieve readiness through PAP as shown in the video below
Here is a progression of optimal load dosage
Strength-speed
Week 1
5x5
70% load at 0.75m/s
RFA = rapid eccentrics
Week 2
5x4
65% load at 0.82m/s
RFA = rapid eccentrics
Week 3
3x3
60% load at 0.9m/s = OPTIMAL POWER
RFA = rapid eccentrics
Speed-strength
Week 1
4x4
55% load at 0.98m/s
RFD = partial average power
Week 2
4x3
50% load at 1.05m/s
RFD = partial average power
Week 3
4x2
45% load at 1.13m/s
RFD = partial average power
Speed
5x3
0-15% load at 1.58m/s - 1.8m/s
Maintain velocity using a velocity monitoring system as shown in the video below
Fatigue can be monitored before the session begins by looking at your athletes wearable technology or utilizing a consistent testing method (i.e. vertical jump height). Fatigue can be minimized during the session by allowing enough rest to hit the target velocity every repetition, and by making changes to the load or stopping the session once the athlete cannot hit the target velocity.
Other considerations
RFA can be trained through rapid eccentrics as shown in the video below
RFD can be monitored by scrolling to “Partial Average Power” on the Tendo unit
 | A guest post by
|