We all know the terms ‘strength,’ ‘power’ and ‘speed and we have a grasp of their value to everything from elite athletic performance to functional fitness. But do you really understand the difference between strength, speed and power?

It’s incredibly common to misunderstand these concepts and this can result in fundamental defects in training and programme design. I will explain what the differences are here so that you are better able to train better or even train others more effectively.


Time to develop force

For an athlete to develop their maximum force (i.e. an expression of maximum strength) takes around 0.3-0.4secs.

That doesn’t sound much but many sporting motions actually take far less time than that. A sprinter’s foot, for example, will only connect with the ground for about 0.089sec when running flat out.

So it’s clear that the opportunity to develop and utilise huge force is in fact quite limited.

Here are two scenarios for you:

a) You are standing in front of a wall and pushing as hard as you possibly can against it.

b) Somebody sprints past you, as he  does so you attempt to push him in the back as hard as you can.

In which scenario are you able to develop the most force?

The wall isn’t going to budge so you have infinite time to develop and exert force. In the second scenario the sprinter is moving at such a speed away from you that there’s practically no time to develop any force.

So this illustrates that our ability to develop force is dependent upon the resistance to movement of the object we are attempting to move.

In the sprinter example:

Clearly his resistance to being moved is very low as he’s already moving himself as quickly as possible in the same direction that you are trying to push him and therefore add force to. As a result there’s minimal time to generate force and that force is of a very low level.

The administration of force

In many sports the participants have to move an inanimate object in some way, whether it’s a discuss, a golf ball, a barbell or a javelin.

performance fitness_2And when looking at the administration of force to such objects it’s evident that the direction of force application has a massive implication to that object’s resistance to being moved.

Attempt to move the object horizontally its resistance to movement is provided by something called ‘inertia.’ When we try and move it vertically, we are adding gravitational force to the equation, plus its inertia. The mass of the object in kilograms determins the resistance to being moved.

Imagine throwing a punch versus putting a shot

The two movements are similar in many ways but of course they feel very different.

A 7.26kg shot putt (which is the size used by adult males) has a significantly greater mass than the gloved fist.

Therefore we can apply far more pure force to the shot. Despite that we will only ever be able to move the shot more slowly than we can throw the gloved fist.

Isometric muscular contraction

Russian strength expert Vladimir Zatsiorski states that when throwing a javelin or putting a shot you have roughly 0.15- 0.18secs to develop maximum force. And it’s probably fair to assume an even faster time for throwing a punch.

Until sufficient force is developed to move the object, the muscular contraction is isometric (static).

With a heavier object such as a very heavy barbell in a deadlift, it stands to reason that more force must be generated before any movement occurs and this will inevitably take more time, perhaps 0.3-0.4secs.

Hopefully this has given you a good grounding in strength, speed and power.  In Part 2 we will look at the Force-Velocity Curve.

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