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.
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.
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.
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
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.
Using a car analogy, imagine a big industrial dump truck. It may not move fast, but it can move big loads.
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.
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.
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.
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.
A drag racer coming off the line and getting up to speed as fast as possible is a good car analogy.
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.
Sprinting speed is very important, but soccer isn’t a track meet. It’s not a linear game, and elite soccer players have great agility in addition to blazing straight-ahead speed.
We divide agility into two key components—quickness and change of direction. Sprinting speed is great, but if you can’t change direction, you’re going to get burned.
Velocity Speed Formula
The Velocity Speed Formula doesn’t apply only to linear sprinting. It also applies to multi-directional movements. The motor control may be different, but Newton’s Laws of Motion still apply, no matter what direction you are traveling. The Velocity Speed Formula has 4 components;
There are differences in how we apply the Formula with agility compared to sprinting. When we compare BIG FORCE, the magnitude may be different, as might the type of muscle contractions.
For agility, SMALL TIME and PROPER DIRECTION usually become more important. When it comes to OPTIMAL RANGE OF MOTION, it’s usually smaller in agility than in sprinting.
Same scientifically based formula, different types and values going into it.
You know the feeling you get watching elite players with incredible quickness? Their movements are crisp, precise and lightning fast. They are able to keep their bodies in total control while making moves.
Lightning-fast movements made in 1 or 2 steps can make all the difference when reacting to an opponent, or leaving one on the ground.
When we consider Quickness, the emphasis moves away from BIG FORCE and changes to SMALL TIME, PROPER DIRECTION and OPTIMAL RANGE OF MOTION.
Body control and balance are big parts of true athletic quickness. Without them, you are like a fish out of water, flailing ineffectively. Athletic quickness requires that you have the balance to keep your body in control. That you can apply ground reactions forces effectively to move you in the PROPER DIRECTION.
This becomes even more evident in soccer, where many of your moves are made with a ball at your feet. You must have excellent single-leg balance, stability and quickness. This let you forces to your body for movement and still maintain good touch on the ball.
When it comes to quickness and your footwork, smaller, not bigger movements, are usually the OPTIMAL RANGE OF MOTION. That’s because you need your feet close to the ground to react and make movements quicker.
The ground reaction force is smaller, but quicker and more reactive. When most people think about strength, they imagine how much someone can lift on a barbell. However, that is only one type of strength.
The Velocity Sports Performance methodology uses six strength types to make athletes more effective in the game. To improve quickness we are more focused on developing Rate of Force Development and Reactive Strength.
This type of strength is all about how fast you can turn on your muscles and generate force. In biomechanics, it’s called Rate of Force Development (RFD).
If an athlete is already moving one way, he or she has to apply force to re-direct his or her momentum. This is Newton’s First Law of Motion. Paraphrased, an object will keep going in the same direction unless acted on by another force. Exercising agility and quickness, an athlete must apply this other force.
During quick agility movements, the foot’s contact with the ground first requires an eccentric muscle action. Eccentric actions occur when the muscle is exerting force one way to resist the athlete’s momentum.
This rapid eccentric force to change momentum is immediately followed by a high RFD to redirect the athlete. Rapid eccentric force coupled with a high RFD in a small time are what we biomechanically call Reactive Strength.
What You Need
Here are some examples of how you might improve your quickness.
Reactive Strength and RFD
Single-Leg Hop Back
Ladder Drills – Backward Single-Leg
Body Control and Dynamic Balance
Single-Leg Med Ball
Change of Direction
Soccer isn’t linear; it constantly changes from one part of the field to another. You have to mark a player who is going one direction, then another. As a soccer player, you need to be good at both.
If the angle of the change is less than 90 degrees, it’s an obtuse (quick) cut. If it’s more than 90 degrees, it’s an acute (sharp) cut. You want to think about this, because the SPEED formula is a little different for each. As a soccer player, you need to be good at both.
Both types of change of direction are common in soccer. They are among the most demanding actions for your muscles and for your energy systems. They also can make or break key moments. If you can’t shake a defender when attacking, or can’t stay glued to the attacker when defending, you lose.
The quick cut usually happens at speed. You’re dribbling down the field and want to make a small change to throw the defender off balance or get to an open space. Or, you may be defending a tracking a player as he or she moves across the field. He or she is trying to lose you, and you need to make small cuts to stay with them.
Sharp cuts also happen. You’re defending a player with the ball racing in one direction. He or she makes a quick stop, pulls the ball back and goes the other way. You’d better make a fast sharp cut to stay with him or her.
The Formula for Change of Direction
The Speed Formula is different for BIG FORCE and SMALL TIME in cutting movements. The quick cut is just that—quick, meaning the time on the ground is smaller and the angle change (and therefore the amount of force applied) is smaller.
This requires Reactive Strength. In the sharp cut, you have to absorb a lot more momentum to stop going one way, then reapply large force to re-accelerate in a new direction. This requires a combination of Eccentric Strength and Speed-Strength.
The Formula is also different in the OPTIMAL RANGE OF MOTION. The sharp cut has to absorb more momentum eccentrically. This means the knees and hips will bend more and/or you will take more steps, whereas the quick cut should only see a little bend at the knees and hips.
Improving Change of Direction
Change of Direction is about the physics of momentum. For best results, you need to understand how to apply the Speed Formula properly. Here are some examples of exercises you can use;
Single-Leg Hurdle Hops and Stick
Activate Base Drills
Inside Box Drill
Wall Crossover Drills
Soccer Agility Makes You A Better Player
True soccer game speed means linear speed and agility. Whether it’s the quickness exhibited with fast footwork and dynamic moves, or rapid changes of direction, you can’t be lacking. These are skills that can be trained through better movement mechanics and by improving the right physical qualities. Take control of your game speed and improve to succeed.
Almost every sport is about more than just running fast or a huge vertical. Pick one, and we’ll bet that most of the action happens around changing direction. For the majority of the athletes with whom we work at Velocity around the country, this means they have to be just as good at stopping as they are at starting. Without good brakes, they simply can’t control their speed.
Three of our coaches have chosen their favorite drill to help their athletes have strong, fast brakes so that they can stop on a dime.
Level Lowering Ladder
One of the most basic skills an athlete needs to change direction is the ability to maintain proper position during deceleration. One of the tools we like to use at Velocity is the agility ladder because it helps focus the athlete on foot position and accuracy in addition to whatever skills we choose to address that day.
To do these drills, athletes first need to have the coordination to perform basic ladder drills well, such as swizzle, scissor switches, and the icky shuffle. Once the athlete can perform each of these without difficulty, they can modify the drill and pause as they drop their center of mass, stopping themselves in the proper position. The most basic, and therefore most important, positions in sports are the square, staggered, and single leg stance. A mini-band can be placed around the athlete’s knees to create awareness of proper knee position. If the athlete adds a medicine ball into the drill, they can work on more ballistic/dynamic eccentric movement with a different stimulus.
The athlete needs to lower his/her center of mass to create “triple flexion” in lower extremity joints: hip, knee, and ankle. The center of mass, knee, and ground contact must be in a good alignment to keep the movement safe and efficient.
Most importantly, the athlete must achieve proper hip hinge and dorsiflexion of the ankle. The vast majority of non-contact injuries occur during deceleration, often at knees or ankles. Learning how to absorb (load) force with proper body position (hip hinge, stable knee, and dorsiflexed ankle) will help prevent these injuries.
Springs and ShocksLadder
The agility ladder is a great tool to help our athletes develop their shocks and springs.
When it comes to speed, athletes need to be springy and quick off the ground. When we talk about “springs,” we mean our athletes’ ability to be faster by using the elastic properties of their muscles.
“Shocks” means having the ability to absorb impact and force so our athletes can stop safely and quickly. This drill emphasizes both abilities and applies to any sport.
How to do the drill:
through the ladder try to be a quick as you can off of the ground. This is where we focus on our springs. When we land we want to land and be under control. The more control we have when decelerating the safer our body will be when changing direction. Most important part of the landing is keeping the body in proper position and not allowing a valgus knee.
Important details to watch are: position and control. We want an athlete to be able to develop the strength and control through the proper range of motion. This is especially important as we begin to add not speed or distance. Do not let athletes progress unless they can properly and effectively let control their landing for at least 2 seconds.
Resisted Deceleration March Series
Slowing down is often the most challenging aspect of changing direction and requires the athlete to absorb more force than at any other phase of the movement. This series of drills teaches athletes to keep good posture and body-alignment during deceleration. When we add a concentric movement (explosiveness) immediately followed by a deceleration phase the drill also develops reactive strength and power in the athlete.
How to do the drills:
Position the athlete in a good athletic base with a resistance band or bungee cord around their waist. The partner holding the band increases resistance by pulling toward the direction where deceleration needs to occur.
The athlete controls their posture while moving toward “the direction of pull”. Their shin is a very important detail and must point away from the direction of pull. This helps their foot dig into the ground and resist the momentum that is trying to keep them moving in their original direction.
The ground contact, knee, and athlete’s center of mass should be in alignment and proper posture maintained.
If you want to incorporate an explosive moment, have the athlete perform any form of change-of-direction movement, such as a lateral push, crossover step, or jump.
Important details to watch are:
Make sure the athlete understand the basic athletic base position. Hip-hinge and dorsiflexion of the ankles are very important.
The level resistance needs to be appropriate to their strength and ability. You may adjust this by using a different size resistance band or the distance between the athlete and partner.
Ground contact, shin angle, knee position, and the athlete’s center of mass stay aligned (away from the direction of pull).
Make sure the athlete is not leaning on the band.
Eccentric control first, then concentric! Make sure your athletes understand how to use the brakes before they hit the gas pedal.
Everyone knows sprinting is an important part of performance in soccer, but it doesn’t take an English Premier League coach to see that other things like quickness, agility, and change of direction are important parts of game speed.
Today, with combinations of GPS and video tracking we have more information than ever about the movement demands of soccer players. At Velocity, we look at data from around the world, in different leagues and levels of competition. We know everything from how many runs players make at different speeds to how often they change direction.
What does it tell us? The game keeps getting faster every decade. It also gets faster as you move up each level, so if you want to compete you’d better be fast.
During a match, a professional player makes between 30 – 40 sprints. We’re not talking about a 100m dash; these sprints range from 1 – 4 seconds over distances of 3 – 39 yards.
Sprinting has two main components: acceleration and maximum (or max) velocity. Acceleration is speeding up rapidly, and maximum velocity is sprinting over ~75% of full speed. Since the sprints can reach 39 yards, and this is far beyond the distance even the best payers can accelerate, we know that soccer players need both.
We know the technique needed for acceleration and for max velocity are very different. The two most apparent differences between acceleration sprint mechanics and max velocity sprint mechanics are body angle and leg action. Soccer players need to develop both movement skills to be exceptional.
While sprinting speed is very important, soccer isn’t a track meet. It’s not a linear game and elite players display incredible agility. To develop soccer specific speed, you need agility. We’ve talked about soccer agility in other articles you can read. Agility can be broken down into two key components: quickness and change of direction.
Sprinting speed is great, but if you can’t change direction, you’re going to get burned.
Lightning fast movements in 1-2 steps can make all the difference in reacting to an opponent or leaving one on the ground.
Change of Direction
The game isn’t linear; it constantly changes direction. A player who can change direction in fewer steps and faster than the opposition has an advantage.
Fast on the Field
So to play your best game, you need several kinds of speed. Players will usually be better at one part or another, but you can’t afford any glaring holes. As an elite player you need:
Change of Direction
You don’t have to leave your soccer specific speed to chance, nor should you. While you may need the right genetics to be the fastest in the world at any of these, through training you can improve – at anything. Improve both your physical attributes and your motor control and you’ll be faster. Speed is a skill, and like any skill, it can be taught.
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