In various social media, the following observation was made several times about my last post: efficiency plays an important role in athletic performance.

Yes. Efficiency is an essential indicator of athletic performance. However, all efficiencies must be in service of greater power production, not simply sought after without a good reason: efficiency has no real benefit when divorced from other variables.

Here’s a quick but illustrative example: It takes a lot more energy to keep a spine straight, with hips, head, and shoulders evenly stacked, than it does to let that spine develop a pronounced thoracic kyphosis—the spine and shoulder curvature we associate with “bad posture.” Does this consume less energy? Yes. But in doing so, it puts a variety of systems—not just muscles, but even the respiratory system—at a disadvantage.

(Tellingly enough, there’s an important relationship between metabolic and aerobic power and the capability to maintain an upright posture).

If we try doing a front squat with bad posture, we’ll set ourselves up for either a plateau or an injury. In effect, we have to resolve this problem by increasing the body’s energy consumption (reducing efficiency) in order to produce the alignment that allows us to correctly perform this movement under load.

Ultimately, however, efficiency is extremely important in sports such as running. This is known as running economy. Elite runners tend to have great running economy, meaning that they use less energy to cover a certain distance.

There are a few ways that running economy can be improved: one is to increase aerobic power. Six times as much energy can be gotten from molecules of glucose that are burned aerobically rather than anaerobically.

Another way is to increase neuromuscular synchronization and power. A knee that collapses in or hip that collapses up during the running stride is known as a “power leak,” meaning that muscles are misaligned and therefore pushing the body up, laterally, or rotationally instead of contributing to driving it forward.

Yet another way to increase running economy is to become smaller. This includes having reduced fat percentage and increased muscle percentage, but it encompasses more than that: runners that are volumetrically smaller have a much easier time traveling distance than runners that are volumetrically larger. Why? If you’re taller, not only will your bones and muscles have to be thicker (in order to retain the same proportions), but then your organs, especially your heart and circulatory system, will be working that much more to pump blood from your toes to your brain.

It doesn’t matter what aspect of running economy you’re talking about. Not only does the economical runner expend less total energy than the non-economical runner, but a greater percentage of total energy expenditure ends up going towards crossing the finish line rather than being lost in vertical, lateral, or torsional oscillation, power leaks, or greater metabolic upkeep.

The question of efficiency or running economy should always be asked in tandem with the question of athletic performance: is seeking some initial efficiency—for example, bowing my upper back because I’m tired—going to hinder my athletic performance or development?

Personally, I believe that “good form” for any athletic activity is “that form which allows us to express greater athletic power.” That’s how it’s defined across martial arts, baseball, the decathlon, and marbles. That should be how we define it in running too.

When a forefoot strike results from all the correct physiological and gait factors, a greater proportion of the stance will be spent on the forefoot, meaning that a greater proportion of the stance phase will go into force production. The stance is shorter overall, and the speed is faster. Is this stride type more costly (and does it produce its own set of injuries)? Maybe, possibly. Sure.

Do certain distances place such a burden on people’s endurance—even that of elite athletes—that they opt out of the “power producing” stride type completely? That’s the billion-dollar question, and given the answer, we might find that it is completely within reason to adopt a hybrid stride or even a heel strike at certain distances, full stop. (Or, you know, we could just walk).

Great form (and great technique) are expenses of energy, both immediate and in terms of time and training. But achieving them will facilitate efficiency at a higher athletic level: we’ll expend more energy, but we’ll be able to apply a greater percentage of that energy towards the achievement of our athletic goals.