Is Youth Strength Training Safe?

is Youth strength training safe

Youth Strength Training Safety

Is resistance training safe for youth athletes?  It’s an important question for every coach and parent.

The bad news…

You still hear it the myths. Weight training will stunt your growth.  It will make athletes muscle bound.  It is dangerous for youth athletes.

The good news…

It’s safe and effective. We’ve seen it for 20 years.  Today it’s backed by research and medical leaders.

Health Benefits of Resistance Training for Youth and Adolescents

Resistance training has been show to be safe and also have a number of health benefits. It helps;

  • Body composition
  • Cardiovascular risk profile
  • Reduce body fat
  • Facilitate weight control
  • Improve insulin sensitivity
  • Strengthen bone
  • Enhancing psychosocial wellbeing

RELATED: Strength Training Is Injury Prevention

Is weight training safe for youth?  Here’s some experts answering.

The scientific and medical communities have come to a conclusion. It is that strength training is safe and beneficial for youth athletes.

  • American Academy of Pediatrics
  • American College of Sports Medicine
  • National Strength and Conditioning Association

Velocity Speed Formula: Big Force

Strength training for speed
Velocity Big 4 Speed Formula
The Speed Formula is the science of speed biomechanics simplified.

Understanding strength training for speed is important for coaches and athletes.  Previously I’ve covered why the Big 4 is such an effective “formula” for speed (read it here). It’s how we analyze movement, teach and come up with drills and programs. No advanced degree in physics or neuroscience necessary. The formula is:

  • Big Force
  • Small Time
  • Proper Direction
  • Optimal Range of Motion
Let’s delve deeper and take a look at the first element; Big Force. It has driven why and how we incorporate certain drills and resistance exercises. It is basic Newtonian physics; you push the ground one way and it pushes you the opposite direction.

How Much Strength Do You Need?

It’s a good question. How much strength do you really need?
Observing the difference in muscular development between a sprinter and a marathoner should give you a clue. Sprinter’s have way more muscle mass. This doesn’t mean you need to just be bigger or become a powerlifter. But biomechanics research does tell us very large forces have to be applied by the athlete to move fast.
You need to produce a Big Force. The strength you need is developed by:
  • sprinting fast,
  • using specific sprint and plyometric drills,
  • and getting in the weight room.

What Is Strength?

For an athlete, strength means a lot more than just how much weight you can lift. There are 6 different strength qualities we train. Focusing on specific strength qualities is how we improve speed.
Strength is how much you can lift, right?
How much you can lift is a great expression of some strength or power qualities. As an Olympic weightlifting coach, I’ve helped athletes go from starting the sport to be on the US National team. I love the strength and power (Strength x Speed) expressed through weightlifting.
Then there’s powerlifting. Squat, deadlift, bench. Many of the coaches on our staff have been competitive powerlifters as well as my friends. These feats of strength are really impressive and it’s a great expression of Max Strength.
Neither is the definition of strength though. They are just great examples of 2 of our 6 specific qualities. Going in-depth is beyond the scope of this writing but here are our 6 types of strength:
  1. Maximum Strength: think powerlifting and even sub max weights. It’s about force and speed is not important.
  2. Eccentric Strength: Think shock absorbers and brakes. When you land, stop, cut, etc… your muscles contract while lengthening. This is an eccentric strength action.
  3. Power (Strength-Speed): Moving fast against a larger load. Think weightlifting or football lineman pushing each other.
  4. Power (Speed- Strength): Moving fast against a light load. Throwing a baseball, jumping, throwing a punch. Moving it fast matters.
  5. Rate of Force Development: How fast you can turn on the muscles. Think of a drag racer analogy. It’s how fast they can go from 0 to speed that matters.
  6. Reactive Strength: Combine a fast & short eccentric stretch, immediately followed by RFD and you have reactive. This is the springy quick step you see in fast footwork.

What Type of Strength Do You Need?

If there are different types of strength, which help you apply a BIG FORCE into the ground? Which will help you get faster?
The answer lies in part on what you are trying to improve. The answer may be different if we are talking about acceleration compared to maximum velocity sprinting. And those may be different than a change of direction.


This is the phase where you are starting and gaining speed. During this phase, the mechanics lead to slightly longer ground contact times. This added time in contact with the ground lets you build up force to push harder. You still have only between 200 – 400 milliseconds, so Max Strength will help, but Speed-Strength is key.
This phase is also characterized by large horizontal and vertical forces. This means that when training strength, you need strength exercises for both pushing backward and down. A good dose of weight room basics like lunges, power cleans help. Combined with vertical and horizontal plyometrics, along with sled work, the results get better.

Maximum Velocity Mechanics

During this phase, you are upright and moving fast. Your foot needs to hit the ground with high forces but it’s not there for long. Elite sprinters are in contact less than 100 milliseconds. You need Max Strength enough to handle the high loads 1.5 – 2.5 times body weight on each leg. You also need to be able to absorb the impact and reapply force quickly. That’s Reactive Strength.
Since you’ve already accelerated, in this phase the forces are mostly vertical. They keep you from falling into the ground. Therefore, weight and plyometric exercises like squats, reactive hurdle jumps, and even jump rope double-unders all contribute.

Change of Direction

When changing direction, the type of strength can depend on how sharp of a cut you make. One situation is a major change of direction where you slow down and re-accelerate. This requires a lot of Eccentric Strength and Strength-Speed. On the other hand, if it’s a quick cut without slowing down or a big range of motion, then it’s more about Reactive Strength and Speed-Strength.
Both these are going to benefit from a mix of weight room and plyometrics. The weight room will include strength exercises and Olympic lifts for power. The plyometrics are going to need to focus on developing horizontal and lateral forces.

Technical Sprint Drills for Strength Development

There is a big misunderstanding of technical speed drills. Most people see a technical drill and naturally believe it’s to develop technique. It makes sense after all, but there is so much more.
Many “technique” drills in speed training are just as important to developing Big Force as the weight room. By refining an athlete’s technique, they become more efficient with the strength they have. They learn to apply it better.
Often many speed drills are really a plyometric exercise themselves. They require putting a lot of force into the ground, in the proper direction. They are in fact the most speed specific form of strength training there is.

Strength Training for Speed

Having good technique and good power output is key to being fast. It’s not an either/or situation, it’s an AND sitution. You need technique AND strength. In every athlete’s development, they go through stages. Sometimes their technique gets ahead of their strength, and vice versa. Make sure you stay on track by developing both and working with a knowledgeable coach who can determine if you need one or the other more.

How To Jump Higher and Hit the Volleyball Harder

How to jump higher

Just about every volleyball player wants to know how to jump higher and hit the ball harder. The best volleyball players have a huge jump and a whip of an arm swing to hit balls through the floor so its understandable.

Technique is always going to be the foundation to success and that comes from hours of on the court.  Still, there is more you can do to get that explosive vertical jump.

This video demonstrates two exercises every volleyball player should include into their workouts to help them dominate on the court or beach.  Coach Rett Larsen should know what he talking about.  He was the performance coach for the Gold Medal team in Womens Volleyball at the 2016 Rio Olympics!


Strength Training Is Injury Prevention

strength training helps prevent injury

Stay In The Game

In elite sports there is a lot of emphasis put on injury prevention.  It doesn’t matter how good you are if you are sitting on the bench, hurt.

Teams and athletes look to us to reduce their risk of injury.  We know there are many parts to injury prevention, but the foundation is often strength.

For the last 20 years, Velocity Sports Performance has known that good strength training is injury prevention.

  • Our experience with athletes in 11 Olympic Games backs it up.
  • Our experience with thousands of professional athletes backs it up.
  • A growing body of scientific research is starting to catch up.

is Youth strength training safe

RELATED:  Is Youth Strength Training Safe?


You need to know: strength is more than just weight on a barbell

Types of Strength
When you speak about strength or being strong, what do you imagine? An athlete hoisting a barbell loaded with heavy weight in a Squat or Bench Press? How about an Olympic weightlifter explosively moving 400 pounds from the floor to over his head in a single movement?
These types of things are often considered “strong,” but what about other sporting actions? How about sprinting at full speed, jumping high, or throwing and kicking?  Most people become unsure whether or how strength is part of these movements.

Defining Strength

What is strength in general and specifically for athletes?  Strength is all about physics, and we are talking about Newton’s 2nd Law of Motion: in a nutshell, Force is equal to Mass multiplied by Acceleration.
Strength is a way of talking about the application of force. An athlete can apply force to the ground, to an opponent, to a ball or other piece of sports equipment, or even internally to his or her own body.

Mass & Magnitude

The mass in this equation is what’s being moved. As an athlete that could be things like:
  • a ball or stick in your hands, to
  • your own body weight (jumping, sprinting and cutting)
  • a 300-pound linemen
  • 500 pounds on a barbell

Acceleration and Time

One thing most people recognize is that in sports, doing things quicker is usually an advantage. Athletes don’t have unlimited time to apply force.
Acceleration is how fast something increases its speed. The faster the acceleration, and thus the speed, the shorter the time.
In sprinting or agility, your foot is in contact with the ground for a limited time. In jumping, there is limited time, and doing it faster than your opponent can be key.  When throwing or kicking a ball or swinging a racket, bat or stick, you want it moving as fast as possible.
Speed of movement matters.

Muscle Action

In physics, force is what we call a “vector.” This means it has a magnitude (how much?) and a direction (which way?). Direction matters because forces can be applied in different directions for different effects.
One thing to consider about direction is whether the muscle is lengthening or shortening during the contraction. When it’s contracting and getting shorter (e.g., bringing the bar up in a Bicep Curl), it’s called a “concentric” action.
If you’re applying force while the muscle lengthens (e.g., while slowly lowering the bar in the 2nd half of the Bicep Curl), it’s called an “eccentric” action.
Types of muscle contractions:
  • CONCENTRIC = Shortening
  • ECCENTRIC = Lengthening
Eccentric and concentric strength are not the same. The same muscles may be used, the same structures and contractile proteins, and the same lints moved. Yet, the brain uses different motor control strategies. For the same action concentrically or eccentrically the motor control is different.

Physiology & Motor Control

Another important thing to understand about strength for athletes is where it comes from.  Often people equate strength with bigger muscles. This is for good reason, because they are related, although not perfectly and not for all types.
Generating force with your body is a combination of the structure of your muscles (size and biological content) and your neuromuscular control. The muscle is your engine to develop horsepower, but your brain is the driver that decides how hard you push the pedal.

Sport-Specific Strength

When we analyze an athlete in his or her sport, we observe various forms of movement. Speed, agility, jumping, throwing, kicking, hitting, twisting, landing and so on are movement caused by how an athlete generates force.
It follows that all types of athletic movement are based on how you generate and apply strength.
Still, how can everything be about strength? Is what your muscles do squatting a full barbell different from what they do when you throw a baseball that only weighs ounces?
The answer to understanding strength is actually composed of different combinations of Newton’s 2nd Law. Force = Mass multiplied by Acceleration

Playing with the Equation

In different movements we manipulate the 3 parts of the equation—Force, Mass and Acceleration (Speed & Time). The we consider the direction of contraction (eccentric or concentric). Now we have a way to analyze sports movements and strength types.
We use this movement-based approach to simplify complex biomechanics into 6 specific types of strength.

6 Types of Strength

Max Strength

This is the basic capability of the muscle to produce a forceful contraction. In application it also involves coordinating multiple muscle groups across multiple joints. The amount of force that can be generated regardless of the time it takes to develop and apply it is called max strength. This is what we call this type of strength even when he or she is under sub-maximal loads.
Maximum strength
Using a car analogy, imagine a big industrial dump truck. It may not move fast, but it can move big loads.

Eccentric Strength

As mentioned before, motor control is different if the action is concentric or eccentric. The capacity to develop high levels of eccentric force is key in sports. Actions such as landing from a jump, stopping, changing direction, winding up to throw a ball and swinging a bat are all eccentric in nature.
When we come to cars, think brakes.  Eccentric strength is like having great brakes on a car to handle those high speeds. An F1 racer has to have great brakes so he or she can go into turns as fast as possible before braking.

Strength-Speed Power

Most sports applications of force involves doing it quickly. Faster is usually better. This is where power comes in. Power is equal to the velocity times the force. Increasing either force or the speed its applied will lead to more power.
strength speed
When an athlete applies force rapidly to a larger load (e.g., blocking another lineman or pushing a bobsled), it’s what we term Strength-Speed Power. “Strength” is first in the name because it’s the bigger component in generating the power. This is like a NASCAR racer who can apply a lot of torque (force), moving the car even at high speeds.

Speed-Strength Power

Here it’s the “speed” of movement (or short time of force application) that is the larger factor in generating the power. Think of an athlete swinging a bat, throwing a ball, or applying force to the ground during high velocity sprinting.
The racing analogy is more akin to motorcycle racing—still applying force at high speeds (like NASCAR), but against much lighter loads.

Rate of Force Development

This is the drag racer. In a drag race, the goal is to go from 0 mph to full speed in as little time as possible. This is the same quality that creates quickness in an athlete. Rapid movement of the limbs, a quick release of the ball throwing or a shot in hockey, fast feet for soccer. Being able to rapidly generate force, regardless of whether the force level is high is known as Rate of Force Development.
Rate of Force Development
A drag racer coming off the line and getting up to speed as fast as possible is a good car analogy.

Reactive Strength

This one’s a combo. It’s a fast eccentric action coupled with a high RFD force. Think of rapid footwork, or a quick step to change direction and juke an opponent. Or the second quick jump when a basketball player comes down and goes back up quickly to get a rebound.
We use a motocross bike as the analogy. Because it has high Rate of Force Development with eccentric-type landings of bumps that gives it that “springy” quality.

Developing Strength that’s Functional

At the end of the day, athletes want the type of strength that will help them perform at the highest level and gives them the resilience to stay healthy.
Every athlete needs a base across all six types of strength. While it seems to make sense to go straight to the specific type of strength for your sport, it’s not the best strategy.
Doing that actually limits development and long term potential. During early stages of strength training, a broad base of strength is important. Even at the elite levels of sport, athletes mix strength types during different parts of the year.
As you progress in your development and level of competition, you begin to focus on the specific qualities. The strength types more important to your sport, your position and even your individual genetics and style of play.
Strength is much more than how much you can lift on the barbell.

4 Rules for designing effective workouts for the female athlete

female athlete

Demands for strength, power, speed and intensity at all levels of women’s sports are greater than ever, so it should come as no surprise that strength and conditioning work should prove a vital component of a developing high school athlete’s specific, year-round physical preparation.

Although sports participation among females has grown exponentially in the past 30 years, since Title IX took effect, the issue of strength and conditioning participation and training adherence for female high school athletes remains a topic that has only recently come to the research forefront.

Given the fact that girls represent approximately 50 percent of the estimated 7 million-plus high school athletes in the U.S., it is imperative that focus be turned to high school females especially. High school girls face the same on-field and on-court demands as their male counterparts, yet differences between the genders do in fact significantly influence the effectiveness of strength training, as well as the overall participation of high school girls in organized strength and conditioning programs.

The purpose of this article is to shed light on unique challenges and considerations that need to be made when working with high school females, before practically discussing (in Part 2) ways in which girls can make strength training more accessible to themselves.

The Basics

In a 2012 research study by Reynolds & Colleagues looking at high school strength and conditioning participation among varsity high school athletes in the state of Idaho, the authors concluded that although 84 percent of high school coaches provided some form of strength and conditioning support to their athletes, only 37 percent actually required it for their teams. Additional findings from this study reinforced anecdotal evidence from large numbers of high school strength coaches nationwide that more boys teams are required to participate in strength training programs than girls teams, and that on average, high school male athletes participate more and train more frequently and consistently than female athletes.

In my recent article on strength training for middle school football players, I described strength as being the “One Thing” any young athlete (irrespective of gender) could develop in the off-season to enhance performance while simultaneously reducing the likelihood of injury.

Applying this same concept to girls, certain general considerations do in fact need to be made when trying to develop strength. Specifically, the following not only affect training outcomes, but also rates of participation among high school girls, leading to the alarming paradox of female athletes needing strength training even more than males, yet on average being less willing to participate in it.

1. Females have physiological differences that need to be taken into account, including lesser rates of absolute strength and power and greater degrees of congenital joint laxity.

Female competitors are built differently than male athletes. Although boys and girls share the same physical structures like muscles, joints, ligaments and tendons, the nature of these structures differs between the genders. To illustrate, girls (on average) possess both fewer and smaller muscle fibers than boys. In addition, through differences in hormonal make-up and physiology, girls also possess greater degrees of congenital joint laxity or global hyper-mobility.

These facts provide the proverbial “double-whammy” for females. They have less natural strength to generate power and more unstable joint surfaces to help control their bodies during sporting actions. A classic example can be witnessed on the basketball court, where upon landing, a typical untrained high school female athlete experiences knee valgus—i.e., their knees caves in. The resultant sheering forces on the knee experienced during landing, combined with a general lack of eccentric muscle strength, leads to females being 2-8 times more likely than their male counterparts to experience an ACL tear during their sporting career. Thus, physical differences between high school males and females clearly have drastic implications from both a sports medicine and sports performance standpoint.

RELATED: STUDY: Female Athletes Are at Higher Risk of Overuse Injuries

2. The fear of “bulking up” is unfounded; however, females do have differences in natural hormone concentrations, impacting muscle mass and training gains.

Anyone who has taken high school biology knows that among other things, hormonal make-up plays a large role in the key physiological differences between the genders. Those who have watched ESPN and Major League Baseball in the last 20 years are familiar with the male hormone testosterone, and what high levels of it (especially when artificially synthesized through anabolic steroids) can do in terms of supporting muscle growth and enhancing strength levels. The fact remains, however, that women too naturally possess testosterone, albeit in much lesser concentration levels than males.

Testosterone is one of the body’s most effective anabolic or “muscle growing” hormones, which can lead to greater strength gains. However, possessing much lower concentrations of these hormones means girls are at a much greater natural disadvantage than boys for attaining muscle mass and subsequent strength gains. This is why the fear of “bulking up” or getting heavy through strength training is so unfounded for girls. The simple truth is that weight training alone will not add tons of pounds to a typical female frame. On the contrary, girls simply do not possess the biochemistry to make sizable gains in lean muscle mass naturally possible. It requires very specific training protocols, nutrition and human biochemistry for girls to attain significant muscle mass (or hypertrophy) gains. Nevertheless, high school coaches point to such unfounded fears as being one of the many reasons high school girls traditionally stay away from the weight room in the first place.

RELATED: Female Athlete’s Guide to Building Muscle And Losing Fat

3. Both upper-body and total-body strength and power must be developed specifically to optimize sporting potential in female athletes.

In addition to having less muscle mass in general, females on average possess less upper-body muscle mass than males. Given the fact that upper-body strength and power are often cited as having one of the most profound impacts upon sports performance skills like spiking a volleyball or shooting a basketball from long range, upper-body strength can be seen as a major limiting factor in performance ability for many females involved in such sports.

In addition, total-body strength deficits have profound performance implications for females involved in all sports. For instance, being able to coordinate the upper and lower extremities when planting or cutting on the field, or transferring power from the ground to overhead (like when serving a tennis ball for example), require total-body power and muscle coordination. Therefore, a lack of upper-body and total-body strength can limit performance dramatically.

4. Females need to train identically to males in the weight room.

Another classic misconception is that girls require entirely different training methodologies to enhance strength and power than boys, such as a greater reliance upon machines or more core work. Nothing could be further from the truth. Although some clear considerations must be taken into account between the genders, like male athletes, female athletes benefit most from strength and conditioning programs built around ground-based compound movements, like the activities I discuss in one of my earlier “Director’s Cut” Podcasts from this year. The simple fact is that males and females need to train equally hard in the weight room to make performance gains and prevent injury.

In summary, strength training is widely regarded as one of the most effective practices for enhancing sports performance and reducing the likelihood of injury in high school athletics. Although afforded generally equal opportunities in the weight room, girls on average participate significantly less than boys in high school strength and conditioning programs, implying that the estimated 3 million-plus high school girls participating in varsity sports annually represent potentially one of the most underserved training populations within the entire field of strength and conditioning. Many myths, including significant muscle gain from strength training, continue to mislead high school girls, leading in part to sub-optimal participation in organized strength training programs. Given that females require the same strength characteristics as males to prevent injury and succeed on the field, it is imperative that high school coaches fully understand the unique difference and challenges of working with high school female populations.

In the next installment, I will discuss how to avoid intimidation in the weight room, so coaches and athletes alike can do their part in ensuring that high school female competitors benefit equally from organized strength and conditioning programs.


  • Fischer, Donald V. “Strategies for Improving Resistance Training Adherence in Female Athletes.” Strength and Conditioning Journal 27.2 (2005): 62-67. Web.
  • “Managing Laxity in Lifters and Athletes.” Tony Gentilcore Managing Laxity in Lifters and Athletes Part 1 Comments. N.p., 13 Aug. 2013. Web. 06 July 2016.
  • “An Athlete’s Nightmare: Tearing the ACL.” An Athlete’s Nightmare: Tearing the ACL. National Institute of Health & The Friends of the National Library of Medicine, 2008. Web. 14 July 2016.
  • Fischer, Donald V. “Strategies for Improving Resistance Training Adherence in Female Athletes.” Strength and Conditioning Journal 27.2 (2005): 62-67. Web.
  • “Managing Laxity in Lifters and Athletes.” Tony Gentilcore Managing Laxity in Lifters and Athletes Part 1 Comments. N.p., 13 Aug. 2013. Web. 06 July 2016.
  • “An Athlete’s Nightmare: Tearing the ACL.” An Athlete’s Nightmare: Tearing the ACL. National Institute of Health.
  • Reynolds, Monica L., Lynda B. Ransdell, Shelley M. Lucas, Linda M. Petlichkoff, and Yong Gao. “An Examination of Current Practices and Gender Differences in Strength and Conditioning in a Sample of Varsity High School Athletic Programs.” Journal of Strength and Conditioning Research 26.1 (2012): 174-83. Web.
  • Stone, Michael H., Meg Stone, and Bill Sands. Principles and Practice of Resistance Training. Champaign, IL: Human Kinetics, 2007. Print.
  • Zatsiorsky, Vladimir M. Science and Practice of Strength Training. 2nd ed. Champaign, IL: Human Kinetics, 2006. Print.

Do athletes need a bigger engine or better brakes?

When it comes to training for performance, many, if not most, people immediately begin thinking about being faster and more powerful. After all, victory often depends on getting to the ball, finish line, goal line, end zone, or basket before your opponent.

RELATED: Learn Velocity’s Proven BIG 4 Speed Formula

This is the same as buying a new car with only one concern: How big is the engine? How fast can it go? How quickly does it get to 60mph? This is, of course, very important to athletic performance.

So, if we stick with our car metaphor, what’s going to happen if you buy a brand new Ferrari but the breaks don’t work? It won’t matter how fast you can go, because, without breaks, you can’t control all that speed.

In fact, the majority of non-contact injuries happen in just this way: athletes can’t manage stopping because they don’t have strong enough brakes and something, well, breaks.

So which one should you pick? The answer is that it depends. If you’re an explosive athlete who can’t change direction quickly, then you probably need better breaks. If your top speed blows away your competition but it takes you too long to get there, then maybe you need a more powerful engine. The first step is to assess where you are now and where you need to be.

RELATED: Why Athletic Strength Is More Than How Much Weight You Can Lift On A Barbell?

At Velocity, we use a battery of tests to see where our athletes are strong and where they need to improve. Based on this and other information, like injury history and goals, our coaches can make smart decisions about what our athletes need in order to improve their performance.

If you want to see how your brakes and engine are working, contact us and schedule testing!