WHAT IS THE ROLE OF STRENGTH IN SPEED, POWER AND AGILITY DEVELOPMENT?

INTRODUCTION

I’m first and foremost a strength guy.

I trained and competed in weightlifting (snatch, clean & jerk) and that was my “entry point” into the strength & conditioning field. My first clients were figure skaters and hockey players who wanted to integrate the Olympic lift variations in to their training.

I then spent a lot of my own training “career” chasing big lifts.

In fact, my own experience could highlights how important strength is for speed development: when I played football, at 19, I posted a dismal 5.21 / 40 yards “sprint” and I was pretty much training like a bodybuilder at the time.

A few years later, after I had moved on to weightlifting and my training gravitated towards heavy squats, clean & jerk and snatch variations, my 40yd time dropped down to 4.54 (laser) with only 1 month of actual sprint training.

However, the information presented in this article is likely going to surprise you because I’m about to say that strength is not as important for speed development as many believe. Furthermore the impact strength has on speed is not really for the reasons we traditionally believe.

But before we go on, just a word about my own improvements. For a long time, I believed that just getting stronger was the main reason for me getting faster. It seemed logical because I didn’t do any actual sprinting work but a lot of strength work. It did play a role, as we will see in a moment, but that is not the whole story.

But looking back at how I trained at the time; every workout started with various jumps. I saw this as my activation work, but it still represented a good overall amount of plyometric work. I also included lots of loaded jumps and medicine ball throws in my training (I have some funny stories about med ball work).

Body composition-wise I also dropped fat and weight during this time. When I played football, I thought I needed to be big to be on the roster. So, I ballooned up to 225-230lbs with a 38” waist. Whereas when I timed at 4.54 I was 195lbs with a 32” waist.

Last but not least, at 19 in my last season’s testing camp, I hit a 500lbs (well, 495lbs) squat and a 550lbs deadlift. Not exactly weak. When I posted my 4.54 my squat was 545 and my deadlift 585lbs. Stronger, but not enough to explain the speed increase, at least not on it’s own.

So how is strength important, really, when it comes to speed development? After all, while we had sprinters like Ben Johnson and Lindford Christie who posted huge squat numbers we also have plenty, including Usain Bolt who display super-speed without being impressive in the weight room. Heck, many don’t even lift; Carl Lewis and Kim Collins for example, who, instead did plyometric work, jumps and throws. They only started lifting when past their prime.

We can also mention that, besides some extremely rare exceptions, powerlifters who squat and deadlift huge weights never have elite level speed (most are quite slow).

Let’s take an objective look at the impact of strength work on getting faster as well as how other “weight room” methods can help you get faster.

THE LIMITATION OF STRENGTH WORK

Strength work itself has a limited transferability to sprinting. In sprinting your ground contact time (the time you have available to apply force in to the floor to propel your body) is around 0.1 to 0.15 seconds (or 100 – 150 milliseconds). This is simply too short of a time period to apply a lot of your force into the floor (look up the force-velocity curve).

While increasing your strength also increases how much force you can apply into the floor (e.g. if you have time to apply 30% of your strength potential, increasing your strength potential will increase how much you can apply on the floor, i.e. increasing your 100% also increases your 30%). Which is certainly why strength work CAN (and does) have a positive impact on speed (which is why I firmly believe it has a role in increasing speed/power).

The problem occurs when your main training focus is solely on strength work. With heavy lifts, it takes a lot more time to reach peak force, 3-4 times longer than you have to apply force into the ground during sprints. The nervous system adapts to what you ask of it. If the bulk of your work is spent there, you will never improve the capacity to have a higher rate of force development (herein, RFD). Which is the real key.

The higher your RFD the faster you can produce force meaning the greater percentage of your max force you can use during an activity with limited time to apply force.

It is interesting to note that during the power variations of the Olympic lifts from the hang or blocks, RFD is about twice as high as during a squat or deadlift.

During clean pulls from the hang or blocks above the knees the RFD is even higher; reaching as much as 3 times higher than during squats and/or deadlifts (depending on the load used).

Interestingly, maximum intensity overcoming isometric pulls (pulling against safety pins above the knees like a deadlift) have an even higher RFD; up to 4-5 times that of a squat/deadlift. Which would indicate that isometrics actually have value when it comes to improving speed (more on that in a future section).

While regular strength work is important to increase your muscle force production potential. By itself, as the main training measure, it likely will not lead to maximal improvements. It could even lead to getting slower if the athlete uses loads and/or an RPE level that leads to grinded/slow reps, frequently.

Build a foundation of force potential with strength work but after that you need more focus on exercises to improve the RFD so that you are to be able to apply more of that force into the floor when running.

THE SUPER CORE

The phenomenon of “core strength” (I prefer the term “core rigidity”) has been increasingly popular over the past 15 years. We now understand how important having a core that can create a lot of tension and rigidity to fixate the trunk is when it comes to various elements of performance.

Let’s look at sprinting. Imagine having to run with a soft pillow for a mid-section. Impossible to be fast, isn’t it?

Firstly because your body will be all over the place, which is inefficient, as it leads to lots of wasted movement and energy. A soft core also lengthens the time you spend on the floor when absorbing your body’s impact force with each step. Obviously making you slower.

Furthermore, to compensate for the lack of central stability/rigidity you will instinctively create peripheral tension (in your limbs, shoulders and back) leading to a stiffer body; which is also a less elastic/reactive body. Essentially, running like a robot instead of a cheetah.

Finally, there will be strength and potential energy loss when you apply force to the floor. When sprinting you push into the floor, which returns the energy, propelling your body. But with a soft core, some of that energy dissipates and the result is less propulsive impulse for the same level of force application.

Thierry Blancon, a former national track and field (high jump) coach in France, has the theory that heavy strength work on squats, deadlifts and the Olympic lift variations acts as a “super core strengthener”.

These movements, especially when performed with heavy weights and done properly, greatly improve the capacity of all of your core muscles (obliques, transversus abdominis, rectus abdominis, spinal erectors and rotators, quadratum lumborum, etc.) to “lock in” your torso while still enabling dynamic actions.

If that is true, and I believe that it is (even though it is not the only element at play), then variations like the front squat, Zercher squat, safety bar squat and hanging band squat would potentially be great tools as they challenge the core more than traditional squats.

Also, exercises like farmer’s walks and split squats/lunges would be good options as they too, challenge the core more than a regular squat and deadlift.

THE CAPACITY TO CREATE RIGID MUSCLES DURING AN ECCENTRIC ACTION

Plyometric actions are actions in which you absorb force and then rapidly overcome that force using the energy accumulated during the force absorption phase. Essentially it is a rapid eccentric action that potentiates the following concentric action.

Three things are important during a plyometric action (including running):

 

1. The transition between eccentric and concentric (absorption to projection) needs to be fast, but not too fast. Plyometric actions have a coupling time (the time you stay in contact with the floor) of 100 to 200ms (0.1 to 0.2 seconds). Longer than that and you become more reliant on strength but will not properly use the reflexive and elastic properties of the muscles. Shorter than that and you simply cannot apply enough force in to the floor to produce maximal speed, even with fast movements.
2. When force absorption is involved, there is always one of the two elements that form the contact (e.g. between your body and the ground) that will act as the energy storage unit. Basically, potential energy is created via the force absorption. That energy is then stored in one of the two “bodies” and that energy can then be used to produce force and movement. The body/element that is the softest or most elastic will store most of the energy from the absorption. The greater the difference in rigidity between the two bodies, the more potential energy will be stored in the more elastic body.

When you run or jump on the ground, your body stores the energy and can use it to produce movement (as your body is the “more elastic” element). If you were to jump on a trampoline, the opposite would happen: the trampoline stores the energy and produces movement. During a jump the force production is a combination of the stretch reflex, stored energy and muscle contraction. When you jump on a trampoline it is a combination of the elastic component provided by the trampoline and muscle strength. That’s why the fastest sprinters run relaxed. It allows them to stay more elastic, to store more potential energy and run faster.

3. But there is a seemingly contradictory element: to have the best force absorption possible, reduced ground contact time (to stay in the optimal zone) and the most powerful stretch reflex, you actually need MORE tendon and muscle rigidity/stiffness. That’s why, one of the characteristics of fast and explosive humans is the ability to rapidly go from relaxed to stiff to relaxed in as little time as humanly possible. For illustration purposes, let’s say that for the first half of the plyometric phase (50-100ms) the muscles must be relaxed to store more potential energy but the second half of that phase (50-100ms) the muscles must become as stiff as possible to avoid dissipating that potential energy and use it to produce a powerful movement.

Strength work, especially the eccentric phase can increase the maximum muscle stiffness (that comes from having a high level of muscle tension/contraction/force production) you can reach.

Again, this doesn’t train the body’s capacity to go from relaxed to rigid in a very short period of time and for a super brief time frame. But it does increase your tension production potential.

In that sense, see resistance training as a way to build your foundation of tension production capacity. It prepares your body for the more specific/advanced methods like shock training (depth jumps and altitude drops) and overspeed eccentrics (more on that later) that you will use later to improve your performance.

Basically, use strength training to increase your tension potential and then specific methods to learn to use as much of that potential in a lightning fast manner.

WORK TOWARD GOING FROM RELAXED TO STIFF AS FAST AS POSSIBLE

By its nature, regular strength training cannot improve your capacity to go from relaxed to maximally stiff in the blink of an eye and back to relaxed immediately after.

That’s why those who naturally have the capacity to turn their muscles on and off extremely fast, as well as have a powerful and highly reactive stretch reflex, will benefit a lot more from traditional strength training.

Those who don’t have that natural capacity highly developed (e.g. those who run “heavy”, make more noise because they slam their heels when sprinting, instinctively take a huge dip and have a slow turnaround when doing a vertical jump) will have a limited capacity to transfer strength gains to speed improvements. They need more emphasis on reactive exercises.

If you have a force plate you can actually measure the dynamic characteristics of a jump and know if the coupling time is long or short. But if you don’t have access to this tool, here are three simple tests that you can use to get a pretty darn good idea of whether the athlete has good reactive capacities.

Test 1 – Elastic to strength ratio jumps

After a proper warm-up and a few preparatory vertical jumps, test your maximum vertical jump under two conditions:

1. Do a regular vertical jump, dipping down and jumping up as high as possible (countermovement jump), measure the height (or watts produced if you have a velocity measurement device).
2. Do a vertical jump from a static start. Go down to the same depth as you do during the dip of your vertical jump but pause there for 2 seconds (to get rid of the stretch reflex) and then jump up as high as possible. Measure the height or watts production. It is very important to avoid “re-dipping” after the pause: you must jump directly from that position.

The greater the difference between both jumps, the more reactive an athlete is.

Countermovement jump = more than 20% higher than static start = very good reactivity

Countermovement jump = 15-19.99% higher than static start = good reactivity

Countermovement jump = 10-14.99% higher than static start = average reactivity

Countermovement jump = 5-9.99% higher than static start = below average reactivity

Countermovement jump = less than 5% higher that static start = poor reactivity

Test 2 – Altitude drop

Have the athlete stand on a box that is the same height as their maximum vertical jump. They must be as relaxed as possible when they are on the box. They step off (not jump off) and remain relaxed until they hit the ground.

They must be able to land directly at a 90-degree knee angle, with the heels as close to the floor as possible, without touching.

They must be able to do that, while staying in balance for 5 reps.

If they “sink in” or lose position, or have the heels strike the floor. Then they don’t have a high reactive capacity.

If they land on their toes (so heels high) that is cheating and they must redo the exercise.

Test 3 – Qualitative vertical jump assessment

The height of the jump doesn’t matter that much here as someone can jump high without having good reactivity (if they can produce lots of force rapidly through voluntary muscle contraction). What we want to look at is the jumping strategy:

1. The depth of the dip. Do NOT give them any technical guidelines, just ask them to jump as high as possible. If they instinctively dip down low (lower than a 90 degrees knee angle) they likely have less reactivity (their brain instinctively increases the range of motion to have more time to apply force). A shorter dip while going for maximum height is the first clue of good reactivity.
2. The coupling time/speed of turnaround. If there is a small delay between the dip (eccentric) and projection (concentric), it is an indication that reactivity is poor. A super-fast turnaround indicates good reactivity

By the way, in that test a rapid dip with a lightning-fast turnaround but with low jumping height would indicate insufficient strength.

None of these tests are perfect. But by doing all three you will get a pretty darn accurate idea of how reactive an athlete is.

Very poor reactivity means that the athlete needs to focus on bringing that up BUT also that the athlete is not yet ready for higher demand reactive methods.

The most powerful exercises to work on reactive capacity are:

Plyometrics

Shock Training

Loaded Jumps (especially when done as a series of consecutive jumps)

Drop & Catch method

Loaded High Knee Running

Olympic Lift power variations from the hang or blocks

Before we get to them, we must first introduce low-intensity plyometric actions, which teach us to use that reactiveness. If you use the most powerful methods right off the bat, chances are that the non-reactive athlete will turn them into strength/muscle contraction movements rather than reactive ones (i.e. the coupling time will be too long) and it will not lead to the improvements we seek.

Low-intensity plyometrics include exercises like hops and small bounds, traditional footing drills (high knees A-skip, for example) and ankle jumps.  All done with the intent to make as little noise as possible and look reflexive/elastic. Stay relaxed, land soft but bouncy.

LOW INTENSITY PLYOMETRICS

The purpose of these simple exercises is to learn the feeling of being “bouncy”. To use the rebound to produce movement, rather than voluntary muscle contractions (they still happen, but should not be your focus).

The low force absorption makes these exercises doable by pretty much anybody who is not injured and makes it a lot easier to maximize the rebounding effect.

Here are a few examples (you can easily come up with many different ones).

Ankle rebounds, Jump rope, High knees running with or without forward movement, Small lateral hops.

HIGH INTENSITY PLYOMETRICS

These include exercises with a higher drop (high propulsion leading to a longer drop and more force to absorb upon landing). Even though you need to produce more height (or distance) it is still important to focus on staying relaxed, bouncy and avoid making noise upon landing.

Here are a few examples:

Hurdle jumps, Knee tuck jumps, Vertical jump series (jumping as soon as you land), Bulgarian split squat jump series.

SHOCK TRAINING

These refer to a method developed by Yuri Verkhoshansky and include depth jumps and altitude drops.

Shock training uses a height slightly higher than your maximum vertical jump, which further increases the amount of force you need to absorb upon landing.

In both exercises you stand on a box, relaxed. Then step-off of the box (do not jump down). You stay relaxed until you hit the ground.

Land anywhere between a full squat position (e.g. for weightlifters to improve their rebound when catching a clean), a 90 degree knee angle (jumping power) or as high as 120 degrees (for some phases of a sprint). The goal is to land softly (land like a cat, don’t make noises) but solidly (do not sink when landing). The weight should be on the front and middle of your feet, the heel should not touch the floor but be as close to it as possible.

This is part is the same for both exercises. In the altitude drop, this is the whole exercise. Whereas in the depth jump, upon landing, jump up either as high as possible (to increase power) or as quickly as possible (to improve reactivity).

OLYMPIC LIFT VARIATIONS

The benefits of the Olympic lift variations are often misunderstood. Yes, they are interesting in the sense that they force you to apply more force into the ground than jumping exercises but do it in a much faster way than squats and other strength lifts.

But one of their main benefits is the absorption that occurs in the catch. Of course, provided you do it properly (catch the bar with a 90-100 degrees knee angle, hips back, chest up).

Right after the pull you transition into moving down under the bar. The quads and glutes relax to allow you to move down fast under the bar. But as soon as you receive the bar, those muscles must fire super-fast. It becomes an overloaded absorption drill and really trains the capacity to go from relaxed to stiff as quickly as possible. Which, as we saw, is super important for speed and power performance.

I’m willing to say that the catch of the power clean or power snatch (when done in the proper position) is actually more important for sprinting performance than the pull (the pull phase being more important for the vertical jump).

In retrospect all the work I did on the power variations of the Olympic lifts (I did mostly the power variations in training, only going down to a squat version when I couldn’t pull the bar high enough, likely not the best strategy to excel at weightlifting), along with all the jumping I did as a “warm-up/activation” was the reason for my speed improvement, not the heavy lifting per se.

By the way, this means that it is not so important to focus on maxing out or focusing on getting your performance on the Olympic lifts (how much weight you can use) up as high as possible.

Yes, more weight means more force to absorb. But even a moderately heavy power clean (let’s say 90-100kg) will provide a significant overload when it comes to going from relaxed to stiff. In fact, going too heavy could decrease the rate of force development in the catch (there would be some sinking action upon catching the weight), which would reduce the effectiveness of the movement.

This also clearly indicates that it is key to receive the bar in the proper position for it to really be beneficial.

Sadly, a lot of athletes do not have the mobility to catch the bar in the correct position. If this is the case it’s best to go with another method.

LOADED JUMPS

Loaded jumps (jump squats, jump split squats, Bulgarian split squat jumps, trap bar jumps, etc.) are very similar to the Olympic lifts in that they both include a high power output and RFD during the concentric phase. They also involve going from relaxed to stiff rapidly in the absorption phase.

Loaded jumps have two main benefits over the Olympic lift variations:

1. They are a lot easier to learn and do not require as much mobility.
2. You can more easily “link” several jumps in a row (jumping as soon as you land). Loaded jumps give you the option of doing each jump individually to focus more on power development or performing a jump series (linking jumps) to develop more reactive capacity.

The main mistake seen with loaded jumps is going too heavy. This is something I see all the time; people using the same type of progression (progressive overload) on explosive exercises as they do with strength movements. Or they use the most weight they can “leave the ground with”. Completely misunderstanding the purpose of the exercise.

Heck, I once saw a hockey player with a max squat of 275lbs use 225lbs on his jump squats!

Here is the thing:

1. If you go too heavy, power production and RFD become too low and they essentially become the same as regular squats. Power production declines past 30% of your max squat. Research indicates that the highest power output is at 20% of your max squat. In reality, it is likely closer to 10% of your max squat, but they didn’t use that load in the research.
2. With heavy loads force absorption will be too slow if you perform single jumps. Likewise the time spent on the floor between reps in a jump series will be too long to train reactive capacities.

I recommend using 10-30% of your maximum squat (depending on the type of loaded jumps and your reactive capacities) on loaded jumps. I favor trap bar jumps over the barbell jump squat (still use back squat as the measure of reference to select the load though).

If someone is strong but has poor reactive capacities, go with 10% of their max squat. If their strength is high but their reactive strength is average or slightly above average you can use 15%. If their strength is high and their reactive strength is also high, they can use 20% and if their strength is low but their reactivity is high, they can use 25%.

OVERSPEED ECCENTRICS AND DROP & CATCH METHODS

When it comes to eccentrics, the goal is to move toward a fast eccentric on your lifting movements.

Louie Simmons (the famed strength Guru from Westside Barbell) conducted an informal study during the dynamic effort work sessions with his lifters (moving 40-60% of their max, plus some bands, for a total average resistance of 70-80%, as fast as possible).

He found that with his lifters, the faster the eccentric was on the dynamic effort squats and benches, the faster the subsequent concentric phase was. This is actually not surprising as this is how the body works during other explosive actions like jumping and sprinting.

Does that mean that slow eccentrics and eccentric overloads are pointless?

No! It just means that you need to understand the purpose of the tool.

I’ve always said that for strength and performance, the purpose of slow eccentrics is to prepare the body to be able to do faster, and eventually super-fast, eccentrics. You can’t perform a fast eccentric if you cannot control the bar and your movement during a normal speed movement.

Slow eccentrics also are better at building up the tendons and more effective at programing a movement pattern in the motor cortex (motor learning).

But don’t forget, the goal is eventually to move toward faster eccentrics.

During a faster eccentric you need to relax the prime movers so that they resist less during the downward movement. Then you need to rapidly create tension (stiffness) when you change direction.

Sound familiar?

The eccentric progression would be:

Slow eccentrics

Paused eccentrics (stato-dynamic)

Eccentric overload

Fast eccentric

Overspeed eccentrics

During overspeed eccentrics you do not attempt to slow down the bar/body on the way down. In fact you actually try to speed up by creating downward acceleration.

Here are two examples:

The goal is to go as fast as you can during the eccentric (which requires staying relaxed), then abruptly stopping the downward movement when you reach the proper position and come back up explosively.

You can immediately go back up explosively to train reactive strength and magnify the stretch reflex. But this is a lot more stressful and should be used with lighter weights (15-25% of your max on the corresponding lift)

The other option is to have a brief pause when you “catch” the eccentric, which will instead work on your capacity to absorb force rapidly. This application can use a bit more weight than the preceding method (30-40% of your max on the corresponding lift).

Note that advanced variations of overspeed eccentrics include using added bands on the bar (bands throw you/the bar down and create more downward acceleration) or the overshoot method in which you use a bar weight that you can accelerate rapidly BUT add weight on the eccentric in the form of weight releasers to be able to go down faster (due to the heavier load).

I much prefer the band option. It is safer and a lot more effective for what we want to develop.

CONCLUSION

How strong is strong enough?

Is strength important for getting faster?

Is traditional strength work optional to get faster?

The answer is, like always, an underwhelming “it depends”.

How beneficial getting stronger is when it comes to speed and power depends on the person you are working with.

Strength training, plyometrics, shock training, Olympic lifting, loaded jumps, overspeed eccentrics and so on are all extremely demanding methods. Spending a lot of resources on things you don’t need to do to get better can rapidly halt progress. It’s your job as a coach to recognize that there will never be a one size-fits all answer and that you need to effectively assess what an athlete needs to reach his full potential.