Why & How To Incorporate Strength In Your Training Year | Strength Training For Sprinters

If you want to be a powerful athlete, you need to be strong relative to your body weight. There may be outliers who achieve their best performances in the absence of any type of resistance training program, but the vast majority of athletes have untapped potential that can be realized in part through a well designed and properly progressed strength training program.

Today we will cover a few of the benefits of strength training as it relates to speed and power athletes, as well as discuss broadly how strength training should be progressed depending on your current levels of strength.

 

Heavy Resistance Training Enhances Motor Unit Recruitment and Downregulates Neuromuscular Inhibition

Motor Unit Recruitment

One reason heavy resistance training is useful for athletes is due to its effects on motor unit recruitment. A motor unit is a nerve which innervates a bundle of muscle fibers, and motor units are typically activated from smallest and slowest to largest and fastest, according to Henneman’s size principle.

Motor unit pools are activated based on the magnitude of force and rate of force development required during a given task (Stone 2018). Essentially, large motor units that innervate type 2 fast twitch muscle fibers are only activated when large forces and RFD are required, and heavy resistance training is a very reliable way to encourage the activation of the larger, more powerful motor units.

If submaximal work is performed where the body only needs to recruit smaller, slower motor units, the body will do just that. Only when given a strong enough stimulus will the body dedicate precious resources to activating energetically demanding fast twitch motor unit pools.

Because of the demands of heavy resistance training, we can use maximal strength oriented exercises to activate higher threshold motor units in training. Once we target these motor unit pools through strength training, it may become easier to activate them while sprinting, enhancing our rate of force development and force production levels when we sprint.

Neuromuscular Inhibition

In my first or second Summer of Strength video, I mentioned that I wanted to overcome inhibition through the use of strength training mixed with some high box jumps. Someone responded saying that this sounded like more of a psychological factor, but in reality neuromuscular inhibition is something that is intrinsic to the nervous system, and it can be lowered and improved through the use of heavy strength training.

Neuromuscular inhibition is the reduction in neural drive during movement that inhibits movement based on feedback from receptors in musculoskeletal tissue. Our bodies act like overprotective parents, preventing us from accessing the full potential of our force production capabilities. 

Research shows us that heavy resistance training can down-regulate these inhibitory feedback systems, allowing for athletes to express greater levels of force, power, and rate of force development (Stone, 2018). Without ever performing strength training, many athletes are limited in their athletic abilities due to the impacts of neuromuscular inhibition.

Anecdotally, I can attest to the fact that during times where I neglected strength training, my ability to produce explosive voluntary movements was inhibited, both in acceleration and jumping exercises. This was evidenced to me both in the feeling of not being able to be as explosive as I wanted to, not being able to jump as high as I am typically capable of, and in a lack of aggressive acceleration despite the intent to produce it. If you’ve ever had a nagging injury that was healed up but still in the back of your mind, you might have some idea of how this inhibition feels.

Obviously when we are injured, it is good to have some inhibition so we do not injure ourselves further, but once we are healthy, this inhibition is a limiting factor in our athleticism. To be the best athlete possible, we need to reduce inhibition so we can access our full levels of explosive ability.

Tissue Stiffness

Tissue stiffness is defined as the relationship between force and the amount of stretch the issue experiences. Because our tissues act like springs, enhancing the stiffness of our springs can allow for greater force production. Through the use of strength training, particularly slow strength training, we can enhance the amount of force tissue can endure without excessive stretching, allowing us to put more force through the tissue without collapsing or yielding excessively.

Phase Potentiation

Phase potentiation is the concept that a phase of training, such as a maximal strength block, raises the potential for improving other qualities in subsequent phases, such as speed-strength and power phase that follows a strength phase. By working on maximal strength earlier in the training year, later phases of training will be more effective due to the greater force output capabilities that the athlete has gained through the use of heavier strength training.

Strength In Sprinting

As we accelerate, sprinters must be able to produce large concentric forces to overcome inertia and build momentum. As we rise into upright sprinting, movements become more cyclical, more dependent on stretch shortening cycles, and the vertical ground reaction forces become very high, requiring high levels of joint stiffness.

A 2008 study by Miyaguchi and Demura found that for stretch shortening cycle movements, eccentric strength showed strong correlations with peak velocity. A meta analysis of Behm et. al. interpreted this by saying:

“An individual who lacks sufficient eccentric strength must accommodate the eccentric forces by absorbing those forces over a longer time period, which would nullify the advantages of SSC actions (Miyaguchi and Demura, 2008).”

That is to say that weaker athletes who cannot withstand and generate large eccentric forces are limited in their ability to produce force during sprinting within the time constraints needed to run fast.

Further supporting the case that maximal strength is important for athletic movements like sprinting and vertical jumping, Mike Stone’s 2018 paper stated:

“Several studies indicated that individuals who squatted >/= 2x their body mass produced greater vertical jump power, sprinted faster and jumped higher, and potentiated earlier and to a greater extent compared to weaker individuals.” (Stone 2018)

Athletes who are stronger are better able to overcome their body mass and express forces throughout a variety of velocities. In contrast, a weaker athlete will be worse at producing forces at all points along the force-velocity curve.

An athlete who is strong will be better able to overcome inertia, accelerate their body mass, and maintain high levels of vertical stiffness as sprinting velocities increase. In contrast, the weaker athlete would accelerate at a slower rate, reach lower top speeds, and struggle to maintain stiffness during upright sprinting.

Training Progressions - Develop Strength Before Power

One might assume that athletes should focus on producing power and using plyometrics rather than strength development, in an effort to be training in a way that seems to be more sport specific. 

While power training and plyometrics offer us a wide range of benefits, a better approach is to first emphasize increases in maximal strength before power and plyometrics become dominant themes in training, that way the athlete has a much stronger foundation upon which to build power production, rate of force development, movement velocity, and joint stiffness.

Once we enhance muscle cross sectional area, joint stiffness, motor unit recruitment, and neuromuscular inhibition through the use of strength training, power and rate of force development training will be more effective.

Here are two quotes from Mike Stone’s 2018 paper:

“Increased maximum strength is strongly associated with the ability to produce not only higher forces, but also increased RFD, velocity, and power.”

“Furthermore, considerable evidence indicates that increased maximum strength lays the foundation for future gains in RFD, velocity, and power.”

With this in mind, we know that we are in fact enhancing more than just strength when we perform strength training. We are developing force, as well as power and rate of force development. Beyond that, as we get stronger, we set ourselves up for even greater development of these time-force factors, as we progress into more power and RFD oriented training over time.

Power training should not be the sole emphasis of training until an athlete has sufficient maximal strength capabilities, roughly characterized by the ability to squat at least twice their bodyweight. Once an athlete is able to produce large forces relative to their body weight, they are then better able to make use of training that develops force-time qualities like power and rate of force development.

Well trained athletes with high relative strength levels (such as >/= 2xBW) are better suited to shift their emphasis toward power output, and can make the most of plyometrics, complexes, and ballistic training. The proportion of emphasis placed on maximal strength and power may shift over time, such that the athlete goes through periods where one quality is emphasized over the other and vice versa.

An athlete who wants to perform depth jumps before they are strong enough will likely spend more time on the ground, experience more amortization, and will not be able to exhibit high levels of stiffness. Their lack of strength makes them collapse under the forces of the depth jump, and might even expose them to higher injury risk. In contrast, someone who is stronger can bounce off of the ground with high levels of stiffness, shorter ground contact times, and without yielding or amortizing significantly. 

Plyometric activities can certainly play a big role in developing athletes, but they are limited in their ability to provide overload in the long term. Adding load to plyometrics is not the best idea, as this would increase joint yielding, ground contact times, and increase the risk of injury. Instead, I would rather use plyometrics with someone who is already strong as a tool to transfer their strength into more sport related movements, rather than as a way to make a weak athlete strong.

Once You’re Strong, Develop Explosive Power

Once your maximal strength qualities are at a sufficient level, power training, ballistic training, plyometrics, and training for enhanced rate of force development can be performed with a greater likelihood of having a positive result.

“...ballistic exercises may lead to neural adaptations including the lowering of recruitment threshold of MUs and may also allow the entire motoneuron pool to be activated within a few milliseconds. Recruiting a greater number of motor units will ultimately lead to greater force production, RFD, and eventually power development.” (Stone, 2018)

Once the athlete is strong enough, they can bring in power oriented and ballistic exercises to take the motor units they recruited through strength training, and make them activate sooner and more completely.

Ballistic exercises are exercises where the load is accelerated through the entire movement, such as a jump squat, certain olympic lift variations, and explosive medicine ball throws. These exercises are more effective than fast exercises which exhibit deceleration in the movement, such as a low load back squat where the second half of the movement is essentially all deceleration.

Once an athlete has developed the requisite strength through an emphasis on maximal strength, ballistic exercises can be included in the program either as standalone exercises or as contrasts and complexes as discussed in my previous video on contrast training.

Rate of force development can be trained through moderate and low load exercises where the load is moved with maximal intent from the beginning of the movement. Even when using lighter loads, the ability to rapidly accelerate the load requires high levels of strength, activation of high threshold motor units, and minimal neuromuscular inhibition. With this in mind, it makes sense that an athlete would need to be strong before they place a large emphasis on power and rate of force development.

Similarly, plyometric exercises can be used once an athlete has sufficient strength levels as a way to transfer force production into movements that require higher velocities of movement, fast stretch shortening cycles, high levels of vertical stiffness, as well as other coordination and balance demands that are relevant to speed and power athletes.

Strength Emphasis May Change, But Strength Is Always A Factor

We do not want to neglect strength once it has been developed to a sufficient level. Rather, we shift workloads when we want to develop power and rate of force development, but we should still include strength oriented lifts. 

At different times of the year, the loading schemes used can emphasize or de-emphasize maximal strength, and these periods can be brought in and out of the program over time. This way we are always maintaining or developing the foundation of our abilities, i.e. strength, while still allowing for enough energy to be available to work on force-time qualities like power and rate of force development.

This is where the use of complexes and contrasts are particularly useful, as they allow for strength to be at least maintained or even developed further, while still leaving a lot of room to work on power and rate of force development.

If at a certain point maximal strength begins to regress, the athlete can go back to emphasizing maximal strength for a period of time, especially if they are not yet in a competitive phase. Once high levels of strength are developed, longer strength phases will not be needed to maintain strength, and even a couple sessions of focusing on heavier loads can make certain that your maximal strength qualities are present ready to be used.

Example Periodization of Strength Qualities

Before we wrap things up, here is the progression suggested by the 2018 Stone paper. Obviously you can do whatever you want, but here is one way to go about it.

Phase 1 - GPP, focusing on strength endurance, muscle cross sectional area, and absolute strength preparation work.

Phase 2 - SPP, focusing on increasing maximal strength.

Phase 3 - Pre-comp/early competitive periods, focusing on speed-strength, power, and maintaining maximal strength.

Phase 4 - Late competitive & peaking periods, focusing on peak rate of force development and power outputs. 

Adapted from Stone 2018.

I do believe we can train multiple qualities at the same time, but each period should have some emphasis based on your hierarchy of needs. For example I am performing 5x100m intermediate tempo sessions and some acceleration sessions within the same weeks that I am working on maximal strength. In addition to my maximal strength lifts I am also performing some ballistic activities, but the proportion of work dedicated to each quality is based on the priority of the current period, meaning that the bulk of my energy is currently directed at enhancing strength. At this time I am willing to take on some extra fatigue due to increasing maximal strength, knowing that I have a lot of time until competition.

As time goes on however, the maximal strength loading will take a back seat and exist in the program at maintenance doses, and the workloads associated with ballistic exercises, power production, RFD, and fast sprinting will increase.


References

    1. Effectiveness of Traditional Strength vs. Power Training on Muscle Strength, Power and Speed with Youth: A Systematic Review and Meta-Analysis, David G. Behm, James D. Young, Joseph H. D. Whitten, Jonathan C. Reid, Patrick J. Quigley, Jonathan Low, Yimeng Li, Camila D. Lima, Daniel D. Hodgson, Anis Chaouachi, Olaf Prieske and Urs Granacher, Front. Physiol., 30 June 2017, https://doi.org/10.3389/fphys.2017.00423
    2. The Importance of Muscular Strength: Training Considerations, Timothy J. Suchomel, Sophia Nimphius, Christopher R. Bellon, Michael H. Stone, Sports Med 2018, https://doi.org/10.1007/s40279-018-0862-z
    3. Relationships between muscle power output using the stretch-shortening cycle and eccentric maximum strength, Kazuyoshi Miyaguchi, Shinichi Demura, J Strength Cond Res. 2008 Nov;22(6):1735-41. doi: 10.1519/JSC.0b013e318182220a.