What Is The Difference Between Strength, Endurance And Power?

As you may have noticed from my style of writing on this blog, I try to be careful with definitions of words and use them in technically accurate ways. I appreciate when someone sends me a kind note pointing out where I may have misused or misunderstood a term in its more precise meaning. I also pay careful attention to how others use technical terms and notice when they are used carefully or when used carelessly, or even misleading. Clear, accurate communication is an art and an ethic. 

 

Slightly Different Words, Very Different Meanings

For example, in my previous series of articles on Moving From Novice To Expert there are these terms I have used – Automatic, Automated, Autonomous, and Automaticity – in describing various aspects of what researchers have disclosed about motor (skills) learning. Though they are all similar with that prefix ‘auto’ in them, they each have slight, but important differences in meaning. Some are used as direct technical descriptions and some are used to make connections to analogies ‘like a machine’ or ‘like a computer’ which help us understand some limited part of how the body or brain work, but not actually what the body or brain is.

One of those terms I have previously taken pains to define more accurately is efficiency (as I did in Judging An Efficient Stroke) because it is thrown around so carelessly in athletic conversation. The observation of a swimmer ‘moving fast’, by itself, is not an indicator that she is efficient. First, a swimmer can be efficient at any speed, fast or slow. Efficiency has to do with how well energy is being used. Usually, it is concerned with using the least amount of energy to get necessary work done, or in other words, using resources as economically as possible. If we are going to label a fast swimmer as efficient there has to be some measurement or comparison of how well energy is being used. We have to show some evidence for this, otherwise there is no argument for efficiency, only speed.

 

Very Different Words, Interrelated Meanings

Here are some terms that are thrown around in athletics in general, that I would like to define more accurately for our purposes. 

• Strength
• Endurance
• Power

I will also give examples in three scenarios we may be familiar with: weight lifting, running and swimming. 

 

What Work Is Being Done?

In weight lifting you have your body weight, you likely have the weight of an object you are moving, and you are working under the pull of gravity. To create more resistance, you add more weight, or move that object farther against gravity.

In running you have your body weight, moving forward, under gravity. To create more resistance, you try to run faster, or run uphill, or run against a head wind.

In swimming you have your body mass, moving forward, against the resistance of water (water density and drag). There is some effect from gravity, but the better your technique, the less this affects negatively. To create more resistance, you increase drag by increasing velocity, or changing your position, shape or movement patterns.

Note: I use the term ‘weight’ when referring to the body on land, and ‘mass’ when referring to the body in water. Those are important technical differences too. Weight is what you get when mass is pulled down by gravity. You have the same mass in your body whether you are floating in outer space, standing on the beach or standing on Mt Everest, or floating in the water. But you have different weight in each scenario because of gravity has more or less pull upon you at different positions. In water, that body mass is pulled down by gravity and pushed up by water pressure, so the effect of gravity is mostly neutralized when positioned right below the surface, and you just have the feel the water pressure as the consequence.

 

Strength Is Central

We might think of strength as the center, with endurance and power being different expressions of strength. Endurance uses strength in one way, and power uses strength in another way.

Endurance is a moderate amount of strength being put to work consistently for a long period of time. Power is an extremely high amount of strength being put to work quickly, for a brief period of time.

The stereotype for endurance in running or swimming is ‘ultra’ distance – running 30 miles or more, and swimming 15 km or more. The pace per mile could be quite slow, like 12-minute miles in running, or 40-minute miles in swimming, but then going for days. This requires a moderate amount of strength applied consistently, lasting a long time.

The stereotype for power in running or swimming are sprints. Usain Bolt ran 100 meters in under 10 seconds. Florent Manaudou swam 50 (short course) meters freestyle in under 21 seconds. This requires an enormous amount of strength applied extremely quickly, lasting just a moment.

All the events between those two extremes require a different ratio of each. Either way, you need strength. It’s a matter of how it will be applied. 

Photo by Victor Freitas on Unsplash

 

Defining Strength, Endurance and Power

Strength

Strength is your ability to overcome resistance. The more resistance you can overcome, the stronger you are. When speaking of strength alone, speed of the movement or overall velocity does not matter so much. Obviously, if you move too slowly, strength will fail early when cells deplete their energy stores. Though speed does not matter so much, it matters to some degree. 

In weight lifting this may be like lifting the maximum amount you can bench press, even just once, even if you execute the full movement slowly. Can you lift your whole body weight? When fully rested, can you lift as much as 1.5x or 2x that amount? What’s your absolute max?

In running or swimming, its a bit different because you can’t change the weight (or mass) you are working with to increase the maximum. To change resistance, you change velocity. Therefore, the fastest velocity you can reach is one way to measure how much strength you have. You can get your body weight (in running) or body mass (in swimming) moving forward at the highest velocity you are capable of. It doesn’t matter how long it took you to reach that speed or how long you could sustain it, only the maximum you reached.

Endurance

Endurance is your ability to overcome a lower amount of resistance, or work, and do it for a longer period of time. The longer you can keep working against some resistance, the more endurance you have. The speed of the movements, or the velocity you travel is not a variable in this definition, although each sport has some standards for what the ‘work’ actually is and sometimes that means moving at some minimum speed.

For endurance, the muscles need to be capable of working continually without breakdown. The metabolic system needs to be able to keep up with supplying energy and removing waste. These two systems have to be ‘strong’ in a way that can keep working for a long time, though not necessarily at high intensity.

In weight lifting it may be like doing bench press, of 20 repetitions with a moderate weight, and doing several cycles of this. The more repetitions and the more cycles you can do, the more endurance you have. You are repeatedly lifting a weight against gravity that is much less than your maximum. You need little or no rest to keep going.

In running, the longer you can keep going the more endurance you have. It doesn’t necessarily have to be fast, just steady. You are moving just your own body weight forward, against gravity, for a long period of time.

Likewise, in swimming, the longer you can keep going, the more distance you cover, the more endurance you have. Speed does not matter, strictly speaking. You are moving just your body mass forward continuously, against the resistance of water.

 

Photo by Nicolas Hoizey on Unsplash

Power

Power is your ability to overcome maximum resistance, and do it in the shortest amount of time. This obviously involves strength, and it matters how quickly you do the work.

In weight lifting, this may be demonstrated by taking your maximum bench press amount and then timing how quickly you can move that weight through the full range.

In running and swimming, power is most easily recognized in sprint races. It is demonstrated by how quickly that runner accelerates to peak speed, faster than his opponents, or the same speed as opponents but holds it a bit longer than they can (I am picturing Usain Bolt in a race that so clearly exemplifies these features of power).

When we get into races of power, we can see that the concepts of endurance and strength blend together to make a powerful athlete win – they have to have great strength to even be capable of the highest velocity, and there has to be some level of endurance to sustain that velocity a bit longer than others can. Then they need power to accelerate faster than others and power in each and every quick stride or stroke. The body not only channels more strength through each movement, in delivers that strength more faster.

And, this is why the terms for strength and power can be confusing in the context of running and swimming because power is measured by speed of the movement, while strength of a runner or swimmer must also be measured by speed. The difference in these contexts is acceleration – how quickly and with what precision can the neural system get those muscles going at maximum? 

Being powerful involves a tremendous amount of neural fitness. Not only do you need to send ‘powerful’ signals through the circuits, those signals need to remain precise and travel faster from brain to muscles.

Endurance would also be greatly aided by having neural fitness. Not only do you need to keep muscles working for hours and hours, they need to remain precise in their movement patterns, as close to the economic ideal as you can get. This will save enormous energy.

So, it would help if we add one more definition to our list because it is important distinction in our context of learning complex motor skills…

 

Add Neural Fitness

Neural fitness is your ability to…

• make a precise movement, close to the ideal pattern,
• to repeat that movement pattern consistently every time,
• to execute that movement pattern more quickly,
• to do it all without having to pay conscious attention to making it happen.

This means the movement pattern has been shifted to the part of the brain that handles autonomous control of movements, as described in Moving From Novice To Expert – Part 3. 

In weight lifting, you would be able to position and move your body in a technically correct bench press, every time, without having to concentrate on having to do it correctly (though concentration would still be a good idea).

In running and in swimming, your body would slip into position, shape, and movements follow the superior pattern precisely, while your conscious attention is free to focus on information coming from your environment.

In our viewpoint of athletics, in weight lifting, running or swimming, we don’t merely train the energy systems. Every action has skill tied to it, every thing has neural connections behind it. You have achieved strength only when you can maintain precise movement patterns under loading, under stress. You have achieved endurance only when you can maintain precise movements for the entire duration. You have achieved power only when you can maintain that precise movement pattern under high load, moving quickly. You have achieved neural strength when you can do all this without having to consciously make your body do it.

***

You may enjoy the entire series on strength:

• What Is The Difference Between Strength, Endurance And Power?
• Your Diet of Strength, Endurance and Power
• Your Lifestyle Of Strength

© 2019 – 2022, Mediterra International, LLC. All rights reserved. Unauthorized use and/or duplication of this material without express and written permission from this site’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Mediterra International, LLC and Mediterraswim.com with appropriate and specific direction to the original content.