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"""Power isn't everything, its the only thing."

- Mario Puzo"

    - Michael Scott"

        - Baylee Munro

 

"Energy Systems in Swimming" by Ferran Rodríguez and Alois Mader is a good review of exactly what the title suggests.

 

And if you love reading only the first line of the Abstract of a paper as much as I do, you will surely see the following:

"Swimming performance can be described as the result of the transformation of the swimmer’s metabolic power into mechanical power with a given energetic efficiency."

 

Link: https://www.researchgate.net/publication/256696190_Energy_systems_in_swimming

 

Earlier we talked about how performance is produced and developed. And here these guys are laying it out in pretty simple terms.

 

Your body provides you with energy (metabolic power) that you use to produce fast swimming (mechanical power) with good technique (energetic efficiency). Or do you use your mind to tell your body to swim fast, and then your body gives you energy if it's in the budget, and that's converted to speed if your technique stays good enough while you're pumping energy through it? Everything is linked.

 

Swimming is quite an uphill battle, with most of the energy produced being sucked away by drag (water resistance), and the worst part is, it gets cubically harder as you go faster. But with a given economy of technique, you have a relationship between power, and speed.

 

But what is Power? Sort of annoying, but first we have to understand Force, Work, and Energy.

 

First, Force is the ability to accelerate a mass. To take a mass (like your body) from a low speed to a higher speed, to accelerate.

If your 70kg body is at a standstill, and you accelerate to 2 meters per second over the period of a second (thus representing an acceleration of 2 meters per second, in that second), you've generated 70kg x 2 m/s²) = 140 Newtons (N) of Force.

 

Second, Work is Force times displacement. Displacement is basically just distance traveled. So if you're sitting on the couch, generate those 140 N of force to change speeds to 2 meters per second over the course of a second, and actually get 1 meter off the couch in the process, you have done 140 N x 1 m = 140 Newton-meters (N·m), or Joules (J).

 

Energy is measured in Joules, and represents the capacity to do work. If you have 140J of energy, you can surely get off the couch.

 

Now I remember why I dropped physics in Grade 12, because I figured out I could do Computer Science rather than Software Engineering, and Comp Sci didn't require Physics 12 (or the Engineering grind). Clearly I would have stayed on the couch.

 

Stay with me now!

 

Power is the rate at which Work is done, or Energy is transfered. It's measured in Joules per Second, which is Watts (W).

 

In cycling, power is the force a cyclist can exert on the pedals, multiplied by the cadence at which their legs move.

That's not unlike swimming, where you have the force that you can exert on the water multiplied by your stroke rate.

 

 

Is that not similar to the Swimming Equation we have talked about previously?

 

Swimming Speed = Distance per Stroke x Stroke Rate

 

Meters per Second = Meters / Stroke x Strokes / Second

 

It is similar, but not the same...

 

Power = Work x Rate

 

Now, here's the distinction between Power and Speed.

 

Power is the force you exert on the water through your stroke, multiplied by your stroke rate. Again, it's a measure of work done, or energy transfer. Speed is the distance you get out of each stroke, multiplied by your stroke rate. It's a measure of accomplishment.

 

Does more Power mean more Speed? Only if the Force you exert on that water is transferred into Distance per Stroke.

Because there's that entire other side of the equation, Drag, which gets cubically more important as you get faster.

 

These factors are connected through that other piece we talked about, Energetic Efficiency, or Economy.

The ability to turn Power into Speed can turn even less-powerful swimmers into extremely fast swimmers.

 

Think of the Power that someone like Ben Proud can generate. The guy is 1.91m / 6'3" and 92kg / 202lbs. 

David Popovici is 1.90m (similar height), and only 80kg / 176lbs. Those are different animals with a 26lb difference.

 

We can clearly see that Ben Proud is more powerful, but also that they are roughly equivalent in their speed.

That is because David Popovici has an extremely high Economy of movement - he's highly efficient.

His bang-for-his-buck is very high, and as a result he can swim a fast 50, an unreal 100/200, and a great 400.

 

If their Speeds are equivalent, but their Power is not, then the Economy must be different, and the resulting Drag must be different.

 

So what we take from this is Power is only as good as the Economy you can express it through. That's Specificity in action (no, this sentence wasn't ChatGPT, but it sure felt like it).

 

But how do you even measure power in swimming? 

EO-Lab is doing their best to make that a reality with the eo SwimBETTER wearables, for the low price of $999+ per set, lol.

 

Link 1: https://www.triathlete.com/training/swimming-with-power/

Link 2: https://www.eolab.com/swimbetter

 

They're a cool piece of tech, just like TritonWear, so if either would like to sponsor me, that would be great.

 

But my point is that directly tracking mechancial power isn't really feasible for more coaches, and yet there's so much to learn from it.

 

Mechanical Power is the expression of Metabolic Power through Energetic Efficiency. So if you can look at Mechanical Power (rather than looking at Speed and trying to infer through a cloud of Drag), and you can look at Metabolic Power (through things like VO2 analyzers such as a gold-standard met cart in a flume or with a snorkel pipe, or something like a VO2Master or Calibre, along with a lactate analyzer like the Lactate Plus), then you can start to untangle things like Efficiency.

 

Why does Metabolic Power matter? Because it's the demand that we put on the athletes implicitly by asking them to swim a certain pace. When you consider in in the context of how much Energy you have left and your proximity to failure, it's a great proxy for Intensity. But more often that not, we're just looking at the Speed, or the Mechanical Power / output, rather than the Metabolic Power.

 

In cycling, it's a super common thing to know your Best Efforts Power Curve, which says how much mechanical power you can hold for any given duration. This graph is even fitted with percentiles, showing that only 2% of people can average 1600 Watts or more for 1 second. On the flip side, pretty much everyone can push about 550W for at least a second. I just got into cycling - even I can do it!

 

 

The swimming speed equivalent of this would be that only 1% of male competitive swimmers can do a 50m Freestyle in 23 seconds or faster. The swimming power equivalent would be something like only 1% of male competitive swimmers have a 23-second mechanical power of 1600W (number completely made up). We intuitively do this for swim times, and the shape or slope of you curve tells you if you've had more success in sprint or distance, but again, swim times are speed-based, rather than power-based. Why is this important?

 

Because you can have someone that's very good at 20 second power that has horrible drag so they can't swim fast, or you might have someone who's very good at 5-minute power but they can't hold their stroke that long to produce mechanical power.

 

You could swim your 200m race pace (a speed metric) on relatively easy 25s that are a low intensity (a power metric), despite that in theory being your ~2-minute speed or power. That's because the reps are so short and the economy is so high that it's actually overly optimistic compared to the race. Versus if you did a push 200 in a training suit, you're more llikely than not going to be at a level of economy below what you'd have in a race suit from a dive, so you're probably going to swim slower and not maintain your pace.

 

Hence why we in swimming generally use intervals rather than continuous efforts - technique can break down, and pace slows down too much. We accept that it is less metabolically relevant, because swimming is a skill-limited sport.

 

Now, in a race situation, you could maintain pace several ways.

 

The simplest is that your power and technique stay the same, so your speed stays the same. Given that every swim race is done in the zone of non-sustainable energy demands if you want to win (the severe and extreme domains of physiology), this is unlikely. You dive into a race and you're primarily using energy already stored in your muscles and replenishing that through your alactic system - but soon enough that's exhausted and you're going into an energy debt because a finite race is non-sustainable by nature.

 

 

If you want to do some more reading in this area, look up "Critical Power" and "W'". I stole the above from Herbie Behm's Twitter, which itself was definitely taken from some physiology paper that I can't find currently. But let's get back to how you can finish your race.

 

Maybe your technique deteriorates, so you try harder (increase metabolic energy demand) to keep the same mechanical output. This works until you get so tired that you either run the energy well dry, or your technique deteriorates further in a positive feedback loop. And this is typically what happens, with either pushing hard to the finish, or the piano falling before you get to the wall. If you've trained to have a lot of energy production, perhaps the well won't run dry. And if you have enough technique stability, maybe it won't collapse. But these are deliberate and trained adaptations.

 

Maybe your energetics deteriorate (insufficient energy funds), so you try to improve your technique so you can do more with less. This is pretty unlikely, but I have definitely done it in a couple races and surprised myself when things held together.

 

Basically, if you want to maintain pace so that your speed stays the same, you need your technique to be the best that it can possibly be at any given point in the race, expecting some economy deterioration due to the loss of the dive and the introduction of fatigue,  but then you are trying to consistently swim at the average metabolic power that you can sustain for the race while the perceived intensity increases to maximal by the very last stroke. 

 

The real game is trying to give your biggest charge with the best technique when speeds are lowest so there's minimal drag.

 

So if you can swim with perfect technique in the later stages of the race when the dive and turns have worn off, you can move past people with relative ease. When it's high-speed and therefore high-drag (such as off the breakout), you always need to play the game of "fast enough", and resist the temptation to play the game of "fastest", which is actually "hardest", because that only incurs unnecessary drag and drains metabolic power.

 

I think the best and most specific training is when everything is aligned with the demands of the race.

 

You're training a relevant metabolic power zone (such as 2-minute metabolic power), you're working in the highest possible skill zone (stroke count, etc.), you're transforming it into the maximal mechanical power to get the speed you want, and the intensity is similar to the race (maximal at the end, but not too early).

 

You can go ahead and train 200m race pace with those 25s on 1:00, but the intensity demands will not be similar, the metabolic power will probably be low, and the mechanical power will be too optimistic. Even if you do lots of reps, it's too gradual of a challenge.

 

You could dive a 150, 175, or 200 at race pace. The intensity will be maximal, which is tough. The metabolic power is only there if you can get up and go for it, and if you're prepared for it. Mechanical power is subject to being able to maintain technique.

 

Somewhere in the middle, perhaps 6x50 @1:00, maybe 3x100 @2:00, maybe you have an intensity that is relevant and progressive to maximal (the last rep vs. the first rep), hopefully the metabolic power is high enough or higher since the reps are short, the technique holds better than if you were doing a straight swim, so the mechanical output is good (and hopefully enough to beat pace by enough that you can make up for having vs. not having to do turns).

 

You could do 4x25 at 100 Pace. You could do 4x25 at 100 Power. The difference is that 100 Power is probably gonna be faster.

Maybe you could do 16x25 at 100 Pace. Maybe you couldn't do 16x25 at 100 Power. Maybe you can make 100 Pace easy.

 

On a given day, maybe your 100 Power is lower. Maybe your technique is off so the times are slower. But it can still be appropriate.

You might have a Metabolic Power Zone that you're hitting, a Mechanical Power Zone that you're hitting, and a Speed or Pace Zone.

 

Metabolic Power becomes Mechanical Power when you have some strength or power in your swimming to create force in your stroke. Mechanical Power becomes Speed when you can avoid drag in your swimming and create distance in your stroke.

 

The message of this blog is that Speed doesn't tell the whole story unless you read between the lines to see Power and Economy.

If you can connect Intensity to Metabolic Power and Mechanical Power, and Power through Economy to create Speed, then you can give your kids the most relevant metabolic adaptations, and then manipulate program variables to keep it neurally relevant.