I keep hearing people say the playoffs are about giving 110%. It’s obvious that 110% is not possible by definition. It’s just an expression. The idea is to give all you have, to “compete,” win your shift, get to the tough areas, get sandy, and win puck battles. Giving 100% means working as hard as possible, and then exceeding maximum capacity with an extra “umph” of heart and tenacity. I get it.

But as a scientist, and a student of the game, I wonder about what it means to even try to approach 100% capacity, let alone 110%.

In truth, if hockey players actually gave 100% effort, they would be making a huge mistake. Let’s think about this a minute.

First of all, what would it mean to truly give 100% effort in hockey? Sure, it’s a theoretical idea, an abstract absolute. That doesn’t mean it can’t be defined.

Consider the following thought experiment: Two elite NHL players are asked to compete against each other in a skating race from goal line to goal line. Sadly for these athletes, we install explosive devices in their jock straps. We tell them that the guy who loses the race will have his stick and pucks blown off. The players line up, and the whistle blows.

What do we know for sure? The guy whose privates went kaboom gave 100%! The other guy, we can’t be sure. [Pause to let the logic of this sink in]

Okay, now that we have established that the concept of 100% effort can be identified, let’s go to the next step.

Pretend now that no bomb goes off. It was a bad joke. The slower skater is relieved to find his pucks are still in the net. What kind of shape is he in? By virtue of having skated to the absolute limit of his capacity, his systems are “blown.” Reaching 100% will render him unable to perform at any level beyond that. If he were asked to scrimmage, most likely he would be incapable. He has, to use an awkward expression, blown his wad.

This is the paradox of maximum capacity. Achieving 100% effort even for a short period is not tactically advantageous for any athlete engaged in a sport like hockey. A 60-minute game, let alone a seven-game series, let alone a 16-win playoff campaign, requires a delicate balance between three key parameters: 1) resource and energy expenditure, 2) reserve capacity of energy and resources, and 3) the rate at which energy and resources can be restored. Outside of rare examples such as the 100-yard dash, giving 100% is actually a pretty bad play.

All human physiologic and cognitive systems are shaped by evolution to optimize the balance of energy expended, energy acquired, and energy in reserve. Throughout human history, 150,000 years before hockey, the primary activity of human beings was food acquisition. Throughout most of human history, food acquisition was a very tricky business. Ice ages, drought, famine, competition, predators—all these factors required humans to adapt the ability to carefully balance the calories needed to acquire food, with the calories that could be procured from the environment. Human foraging evolved to select humans with a penchant for slow grazing in the local environment for nuts, berries, bugs, bark and roots. In the primordial world of early humans, giving 100% meant hunting large animals with rocks and clubs. If you fail, you have depleted energy reserves, traveling long distances, and you go hungry. Great for 4th of July picnics, not smart for everyday dining!

Modern athletes now function in a world where optimizing energy expenditure and energy reserves has taken on unprecedented sophistication. The reason NHL players are now faster, bigger, and more skilled than ever has more to do with twelve-month conditioning, nutrition, and using scientific methods to balance resource expenditure with reserve capacity.

In modern hockey, nothing could be more disastrous for a player than to give 100% for even one shift of the ice. That player would be dead at worst at the end, or rendered useless for the rest of the game.

Let’s imagine for a moment that total output capacity as a percent of theoretical maximum could be quantified and tracked. We do this all the time in many physiologic systems (think of VO₂ max in an exercise stress test). Some day not far away, this will be possible. What would the optimal output level be? One that leads to maximum maintainable performance level while minimizing risk of damage. My guess is 64.5%.

Someday, I’d love to hear a player say this during a post-game interview: “I think we all gave 64.5% tonight.”