What We Test and Why

A parent's guide to your athlete's progress report

Every quarter we hand you a report full of numbers. This page explains what each number is, why we test it, and how we improve it.

Fair warning: this is more detail than anyone asked for. Skim it, keep it as a reference, or ignore it entirely. It exists because we wanted one place that lays out what we test and why, for our coaches, our athletes, and any parent who wants to know what their kid is actually doing in here and how much thought went into it. Getting this right matters to us. We want a program built on research rather than on tradition or whatever is popular this year, and we want it to be the best one we are capable of building.

If you have a question about your athlete's report, the answer is probably somewhere on this page. If it is not, reach out. I love talking training and I would much rather have the conversation than have you wondering.

One thing to keep in mind as you read. No single number tells the story. We test a spread of qualities on purpose, because the pattern across the tests is what tells us where your athlete is strongest and where the biggest opportunity is.

These are the KPIs

Every business tracks a handful of numbers that tell it whether the work is actually working. This is our version of that.

We strength train for three reasons. It dramatically reduces injury risk. It builds usable mobility. And it is supposed to make the athlete better at the things their sport actually asks for: accelerating, running fast, jumping, and changing direction.

That third one is the whole point, and it is the one nobody checks. So we check it. If an athlete is getting stronger in here and their acceleration, top speed, and vertical jump are not moving, something is wrong with what we are doing and we need to know about it. These numbers are how we hold ourselves accountable.

The battery at a glance

If you read nothing else on this page, read this.

Test What it measures

5-10 Fly Acceleration. The burst off the line.

10-10 and 20-10 Fly Transition speed, from acceleration into top speed.

Max Velocity Top speed.

505 Change of direction. Plant, redirect, go.

Broad Jump Horizontal power.

Standing Vertical Lower body power.

Approach Jump Power expressed at speed.

RSI Springiness. Time spent on the ground.

Single Leg RSI Springiness one leg at a time, plus symmetry.

Back Squat Lower body strength.

Front Squat Leg strength, posture, mobility.

Deadlift Posterior chain strength.

Clean Rate of force development, and frankly too many other things to list.

Snatch Everything the clean measures, plus overhead. Also too many to list.

Press and Push Press Overhead strength, power, and mobility.

Chin Up Relative strength Upper Body.

Speed

Speed is not one quality. Getting off the line fast and running fast at top speed are two different skills, and plenty of athletes are good at one and poor at the other. That is why we break the sprint into pieces instead of just timing a 40.

A logistics note: the 5-10 Fly is the one we run in the gym at the Wilmington location. The 10-10, the 20-10, and max velocity happen at speed training during the week, where we have the room to do them properly.

1. The 5-10 Fly

What it is. A 15 yard sprint where we only time the back 10. The athlete builds through the first 5 yards, then runs through a timed 10 yard zone.

What it measures. Acceleration. The burst off the line.

How we improve it. Acceleration is a horizontal force problem. It is not just how much force an athlete puts into the ground, it is how much of that force they direct forward, and how fast. We attack it four ways: relative strength, resisted sprints on our sprint machine, horizontal jumping, and a lot of reps simply accelerating.

The resisted sprints and horizontal jumps do double duty. They build horizontal power, and they are our best teaching tools. We can talk to a kid until we are blue in the face about shin angle and where the foot should land, and it will not do a fraction of what one rep on the resisted sprint does. Against resistance, the foot has to land under the hip, the athlete has to be on the ball of the foot, and the forward lean and shin angle have to be right, or the rep simply does not work. The drill teaches the position for us.

This is also why we do not spend much time on short cone drills, ladder drills, and quick choppy feet work. They are not correlated with improving acceleration.

The research: When researchers measured ground reaction forces during sprinting, what predicted performance was not the total amount of force athletes produced. It was how much of that force they directed forward. Athletes who put plenty of force into the ground without pointing it in the right direction did not accelerate well. Fast feet that do not move you down the field are just fast feet. Technical Ability of Force Application as a Determinant Factor of Sprint Performance

The research: A systematic review and meta analysis of resisted sled training found it to be an effective method for improving sprint performance, with the largest effects in the early acceleration phase. The Effectiveness of Resisted Sled Training for Sprint Performance

Why it matters. We all know this one instinctively. The kid who gets from point A to point B faster than the kid across from them is setting themselves up to succeed, in every sport there is. And in field and court sports, the overwhelming majority of sprints are short. Most plays are decided inside the first 10 yards.

2. The 10-10 and 20-10 Flys

What they are. Same idea as the 5-10, with longer build ups. On the 10-10, the athlete accelerates through 10 yards and we time the next 10. On the 20-10, they build through 20 yards and we time the next 10.

What they measure. Transition speed. How well an athlete transitions out of acceleration and into max velocity. Some kids have a genuinely hard time with this, and it does not show up on any other test.

How we improve it. The same horizontal force qualities that drive acceleration, plus sprint mechanics as the athlete comes upright, plus real exposure to running at high speed.

Why it matters. This is where a lot of athletes stall out. Great first step, then they stop gaining ground. It is also the range most sport testing lives in. A baseball player gets tested in a 60. A football player gets tested in a 40. And an athlete like a soccer player, who may never get formally tested at all, spends most of a game doing exactly this: already moving, then turning on the burst.

3. Max Velocity

What it is. The athlete's top speed, measured over a longer run once they are fully upright and rolling.

What it measures. How fast the athlete can actually run.

How we improve it. Mechanics through our wicket runs and dribble series, and reps at true top speed with full recovery. Top speed only improves by running at top speed. There is no drill that replicates it and no way to sneak it in at the end of a session when everyone is tired. It needs distance, it needs fresh legs, and it needs space. That is what Saturdays at the track are for.

Why it matters. Speed kills, and max velocity is one of the better general markers of athleticism we have.

It is also the most neglected quality in youth sports. At the college level this is settled. There are almost no major Division I programs that do not run fly sprints now, across every sport, because they know what it does for overall athleticism. Club and high school programs largely have not caught up. Most teams either practice the sport or they condition, and true speed work never happens, even though every coach in the country says they want faster athletes.

Here is the part that surprises people. Even if your athlete is a volleyball or basketball player who never reaches top speed in their sport, sprinting at max velocity is still one of the most valuable things they can do. Nothing else we have access to comes close to the demand. At top speed the foot is on the ground for less than a tenth of a second, which means the muscles have to contract and produce force faster than in any lift, any jump, or any drill we could program. The limbs move faster. The forces are higher. It is the most extreme plyometric activity the human body can perform.

That is why it bleeds down into everything else. Rate of force development, elasticity, limb speed, and the nervous system's ability to tell the body to go all improve from it, and those show up as a higher jump, a faster first step, and a sharper cut.

The research: Reviews of reactive strength report that elite sprinters spend under 100 milliseconds on the ground per step at top speed, which is a rate of force development no gym exercise reproduces. Reactive Strength Index as a Key Performance Indicator

And on hamstrings. If pulled hamstrings are what worry you, the single most protective thing an athlete can do is keep sprinting at or near top speed. Stretching does not do this. Strength work matters and is part of the answer, but it does not replace the exposure.

The research: A 2025 review of sprint training found that programmed exposure to running at 80 to 90 percent of max speed or higher, combined with strength work and mechanics coaching, was associated with hamstring injury reductions ranging from 56 to 94 percent. The same review criticized generic exercises for failing to replicate the demands of high speed running. Sprint Training for Hamstring Injury Prevention

Change of Direction

4. The 505

What it is. The athlete sprints 10 yards, plants a foot on the line, and sprints back the other direction. We time the turn.

What it measures. Agility in the way it actually shows up in sport. Getting up to speed, stopping on a dime, and going the other way. This is the number behind reacting to a ball, beating a defender, and changing direction under control.

How we improve it. When people picture agility training, they usually picture cone drills and ladders. Those may have a place. They are just not where the return is.

Think about what the body has to do to plant and redirect. It has to absorb a large amount of force in a fraction of a second, and then put that force back into the ground going the other way. That is a strength and elasticity problem, not a footwork problem. So we train it with relative strength, with eccentric and deceleration work for the absorbing side, and with plyometrics for the redirecting side, especially the lateral bounds, lateral hops, and leaps we run in nearly every warm up. An athlete who cannot absorb a hard plant has nothing to redirect out of.

The research: In a study of 196 athletes, eccentric strength measures explained 25 percent of the variance in a 90 degree change of direction and 37 percent in a 180 degree turn, which is close to the demand of the 505. A separate meta analysis of eccentric overload training found substantially faster change of direction times in the trained groups. Eccentric muscle capability and change of direction speed

The research: A 2024 systematic review of the biomechanical determinants of change of direction recommends exactly this combination: plyometrics that shorten ground contact time, eccentric resistance training, horizontally oriented plyometrics for sharper cuts, and a mix of plyometric, resistance, and sprint training for overall change of direction performance. Biomechanical determinants of change of direction performance

Why it matters. For most field and court athletes this quality is closer to the game than a straight line sprint is.

Power and Elasticity

Strength is how much force an athlete can produce. Power is how fast they can produce it. Elasticity is how well they recycle it. These tests separate those out.

5. Broad Jump

What it is. A standing two foot jump for distance.

What it measures. Horizontal power.

How we improve it. Relative strength first, then a lot of horizontal jumping. If we want an athlete to produce force in a direction, we train them producing force in that direction.

Why it matters. The broad jump is highly correlated with acceleration, which makes it one of the most useful tests we have for field sport athletes. If this number is going up, the athlete is almost always getting faster off the line.

6. Standing Vertical Jump

What it is. A standing jump with a countermovement, measured on our jump mat.

What it measures. Lower body power.

How we improve it. Three levers, and we pull all three. Get stronger, so there is more force available. Olympic lift, so that force can be expressed quickly. Jump, so the elastic and reactive qualities develop. Strength alone gets an athlete part of the way. The combination is what actually moves this number.

The research: A review in Sports Medicine found greater muscular strength is associated with better jumping, sprinting, and change of direction. A meta analysis of 34 weightlifting studies found improvements in countermovement jump, sprint times, and squat max, particularly when weightlifting was combined with traditional strength training. And a meta analysis of plyometric training in female athletes found a moderate effect on countermovement jump height overall, rising to a large effect for programs running longer than 10 weeks. Muscular Strength in Athletic Performance, Weightlifting training on jumping and sprinting, Plyometric Training on Vertical Jump Performance in Female Athletes

The research: In elite long jumpers, eight weeks of strength training plus plyometrics improved countermovement jump height and lower limb stiffness, while strength training alone did not. Both groups got stronger. Only the combined group jumped higher. Combined strength and plyometric training on jump performance

Why it matters. Obvious for basketball and volleyball. Beyond those, it is a clean general measure of lower body power that we can retest reliably.

7. Approach Jump

What it is. A running jump, measured on a Vertec. We measure the athlete's standing reach first, so the number you see is true jump height above their reach.

What it measures. Power expressed at speed, which is what a jumping athlete actually does in their sport.

How we improve it. For a volleyball player, part of it is practicing the approach, which is a skill. The bigger lever is raising the ceiling. Jumping in a nutshell is how much force the body can put into the ground and how quickly it can put it there. So the same three levers apply: get stronger, Olympic lift to produce that force faster, and jump to build the elastic side.

Why it matters. For a volleyball or basketball athlete, this is the number that shows up on the court.

One thing to know. Sometimes the standing vertical reads higher than the approach jump, which looks backwards. That is a measurement artifact. The jump mat is very consistent for tracking change over time, but it inflates the raw number slightly. The Vertec approach number is the more literal one. Compare each test to itself over time rather than across the two.

8. RSI, Reactive Strength Index

What it is. A five jump test. The athlete performs five repeated pogo hops, and we combine how high they jump with how long their foot is on the ground.

What it measures. Springiness. How quickly an athlete can absorb force and put it back into the ground.

How we improve it. The quick ground contact plyometrics we run in nearly every warm up are aimed directly at this. We test it to put a number on something we are already training every session.

Why it matters. Ground contact time is one of the sharpest dividing lines in sprinting. The slower an athlete is, the longer the foot stays down. Springiness is what lets an athlete keep building speed once they are up and moving, which is exactly the zone our fly sprints live in.

The research: In field sport athletes, RSI correlated strongly with the 5 to 10, 10 to 20, and 20 to 30 meter splits. Athletes with higher RSI had shorter ground contact times and better late acceleration without giving up step length. The only zone where RSI showed no relationship was the first few steps out of a dead stop, which is not what our fly sprints measure. Reactive Strength and Late Phase Sprint Acceleration

9. Single Leg RSI, Left and Right

What it is. The same test, one leg at a time. Five hops on the left, five on the right.

What it measures. Elastic quality on a single leg, which is closer to sprinting than any two footed test, since sprinting is really a series of single leg contacts. And symmetry.

How we read it. We compare left to right. If one side is meaningfully behind, that is something we address in the program directly rather than hoping it evens out.

How we improve it. The plyometric warm ups we do every single day. If you have ever wondered why our warm ups look the way they do, this is a large part of the answer. They are not filler before the real session. They are the session for this quality.

Why it matters. Asymmetry is worth catching before it becomes a problem, and single leg elasticity carries over to running better than the bilateral version.

How all of these numbers actually move

Before we get to the strength tests, here is the honest answer to what makes any of this improve.

Consistency. Athletes who are in here at least two days a week, week after week, improve. Athletes who come in waves do not. There is no drill that substitutes for showing up.

Relative strength. Strength in proportion to body weight. It is the single biggest driver across acceleration, jumping, change of direction, and top speed. A stronger athlete at the same body weight is a faster, more explosive athlete, nearly every time.

Coach selected loads. Athletes here do not put weight on the bar based on how they feel that day. A coach makes that call, every time, on every lift. Our two biggest jobs on the floor are cueing good form and choosing the right weight. Some of our older athletes get very good at self selecting eventually, but that is earned, not assumed.

This is why we test one rep maxes. The max is not the point. The point is that it lets us prescribe correctly. If an athlete is doing a set of five on the front squat, we know they should be somewhere around 65 to 75 percent of their max, and now we can put a real number on their program instead of guessing. Every athlete's percentages and working weights are written on their program and tracked.

Technique above load, especially on the Olympic lifts. With the clean and the snatch, we are training technical precision and a fast bar far more than how much is on the bar. A heavy ugly clean is worth less than nothing to a developing athlete.

Strength

The most important paragraph on this page

We get asked about stretching and injury prevention constantly, and honestly it is the thing we care about most. We want athletes healthy and mobile so they can keep playing their sport, keep training, and keep getting better. Everything else on this page sits downstream of that.

I have spent countless hours researching how to actually keep athletes healthy, and years watching what works and what does not with the kids in this building. On this particular question the research is about as clear as sports science ever gets, and it points somewhere most people do not expect.

On injury prevention. The answer is not stretching. It is getting strong.

The research: A meta analysis in the British Journal of Sports Medicine pooled 25 randomized controlled trials covering more than 26,000 people and roughly 3,500 injuries. Strength training reduced sports injuries to less than one third, and overuse injuries were close to halved. Every prevention approach studied showed a favorable estimate except stretching. A follow up review by the same group found the protective effect to be dose dependent, meaning more strength meant more protection. The effectiveness of exercise interventions to prevent sports injuries

On mobility. We believe in it. We just build it through full range of motion lifting rather than static stretching, because that is what holds up. The deep positions in a front squat, a clean, and especially a snatch are not incidental. They are how we build usable range at the ankle, knee, hip, shoulder, and upper back.

The research: A meta analysis of 55 studies in Sports Medicine found that resistance training improves joint range of motion, with no significant difference compared to stretching. Notably, bodyweight only training did not produce the effect. It took training with external load through full ranges. Resistance Training Induces Improvements in Range of Motion

How we test the strength lifts

Every strength test below is a tested one rep max to our form standard. That last part matters. If the bar speed dies or the position starts to break down, we cut the athlete off, even if they think they have more in them. Does every rep in the building look pristine? No. This is a learning environment and these kids are learning. But we do not let bad reps fly, and we will not put a number on the board that was earned with poor posture or poor technique. We cut them off before it ever gets to that point.

10. Back Squat

What it measures. Lower body strength.

Why it matters. If we can get a developing athlete's squat to one times body weight, then one and a half, and eventually approaching two times body weight with genuinely good form, it lifts almost every other number on this page. Acceleration, vertical jump, and change of direction all improve. It is the closest thing to a cheat code in youth athletic development.

11. Front Squat

What it measures. Lower body and leg strength, relative strength, and a large amount of mobility. To front squat well an athlete needs real range at the ankle, knee, and hip, plus the upper back and shoulder position to hold the rack.

Why it matters. The front squat tends to track more closely with jumping than the back squat does, and the position carries directly over to catching cleans. It is also one of the best tools we have for teaching a kid how to squat in the first place, because a front loaded bar demands a very upright torso, strong legs, and good posture. The lift will not go up without them.

12. Deadlift

What it measures. Posterior chain strength. Glutes, hamstrings, and back working together.

Why it matters. The posterior chain is the engine behind acceleration, and this test tracks closely with sprinting. Just as important, the deadlift done correctly reinforces good posture. We do not let athletes pull with a rounded back and we do not chase a number at the expense of position. This lift is about using the legs and hips, not just the back. Every athlete is going to be asked to pick a bar up off the ground eventually, in a high school weight room or a college one, and plenty of things off the ground long after they are done playing. They should already know how to do it the right way.

13. Clean

What it measures. Rate of force development, which is how quickly an athlete can express the strength they have. Also strength, power, total body coordination, and technical precision, which is badly undervalued as an athletic quality.

Why it matters. Acceleration and jumping both come down to how much force an athlete puts into the ground and how fast they put it there, and the clean trains exactly that. There is a reason almost every track and field program in the country uses Olympic lifting variations.

There is a second reason we teach these lifts, and it is the one we feel strongest about. The Olympic lifts are the status quo of the strength and conditioning industry. Most high school and college programs use them, and many do not take the time to teach them properly. Athletes end up guessing. A clean turns into an arm and back exercise instead of an explosive leg and hip exercise, and they get almost nothing out of it. Someone is going to prescribe these lifts to your athlete eventually. We would rather they arrive already knowing how to move, what heavy should feel like, what too heavy feels like, and how to stay safe under a bar.

14. Snatch

What it measures. Everything the clean measures, plus the most demanding ranges of motion we ask for anywhere in the program. The snatch requires real mobility at the ankle, knee, hip, shoulder, and upper back all at once, under load and at speed.

Why it matters. Overhead athletes spend an enormous amount of time with their arms above their head, and they should be strong there. We do not know of an exercise that returns more in that position than catching snatches and overhead squatting. Thoracic mobility, shoulder stabilizing musculature, upward scapular rotation: these are the qualities everyone agrees matter for throwing and overhead athletes, and the snatch trains all of them at once, under load.

It is hard to teach, and a lot of coaches skip it for that reason. But once an athlete can genuinely snatch, every other lift in the weight room becomes easy for them. We see it over and over.

15. Press, Push Press, and Jerk

What it measures. Overhead strength, power, and mobility.

How the progression works. This one is a ladder, and where an athlete sits on it depends on what they have earned.

We start everyone with the strict press. The goal there is simple: teach an athlete to press overhead with good technique, and build the mobility and stability to hold a solid overhead position while they do it. Nothing moves forward until that looks right.

Once it does, we move them to the push press. Same overhead position, now with the legs involved. This is where an athlete learns to transfer power from the hips through the arms, which is the exact sequence behind throwing, hitting, and serving. It also lets them handle noticeably more weight, which is its own kind of confidence.

From there, some athletes learn the power jerk, which allows more load still, and demands more coordination and more power. And a small number of athletes end up Olympic lifting with us, in which case we teach the split jerk. That is rare for most team sport athletes, and that is fine. Very few of them need it.

Why it matters. Overhead strength gets ignored in a lot of youth programs, usually because the mobility is not there and it is easier to skip. Skipping it does not build the mobility. Pressing correctly, and progressing only when the position is earned, does.

16. Chin Up

What it measures. Relative strength. Upper body pulling strength in proportion to body weight.

Why it matters. Relative strength is what actually moves an athlete. We do not typically test body composition here, and I am careful about it. I have no interest in putting a number in front of a young athlete that can turn into a problem. The chin up quietly captures a lot of the same information in a much healthier frame. When an athlete is building lean muscle, getting stronger, and sitting at a healthy body weight, their chin ups and their vertical jump tend to improve together.

What about core training?

We get this question constantly, so here is our honest answer.

Yes, a strong midsection matters. No, crunches and planks are not the best way to build one.

The lifts on this list are the most demanding core work in the building. Catching a clean, holding position in a front squat, and driving a push press overhead all require the trunk to absorb heavy load and transfer force from the hips to the arms. That transfer is the exact thing that hitting, throwing, and serving depend on.

The research: Researchers compared trunk muscle activation during heavy squats and deadlifts against dedicated isometric core exercises like the superman and the side bridge. Activation during the loaded squat exceeded the superman by 65 percent and the side bridge by 53 percent, and the authors concluded that athletes doing heavy, upright, dynamic lifting may not need added core stability work. Trunk muscle activation during dynamic weight training exercises

The research: Imaging work comparing lateral abdominal muscle thickness in competitive weightlifters against matched controls found that Olympic weightlifting appears to preferentially develop the internal oblique. Lateral abdominal muscle thickness in weightlifters

So do we do isolated core work? Yes, some. But if you made us pick between an athlete doing crunches and an athlete learning to clean, we would take the clean every single time.

How to use this report

Compare your athlete to their own previous numbers first. That is the number that matters most, because it is the one we control.

Then look at the shape of the results, not just the individual scores. Where the athlete is furthest behind relative to their peers is usually where we are pointed next, and it is the reason two athletes in the same class can be running very different programs.

If anything in your report is unclear, ask us. We would much rather explain a number than have it sit there meaning nothing to you.