Economics is probably not something you associate with fitness. However, there is a concept from econ that may also apply to your workout — and learning it can help you ensure that every second you put into your exercise is helping you achieve your goals, rather than wasting your time.
If you didn’t sleep through Economics 101, you may recall the law of diminishing returns. Whether or not you recognize this term, the gist is: If you increase one factor of production (say number of workers) but not others (time, machines, etc.), the resulting profits, benefits or other positive outcomes slowly decrease.
In layman’s terms: You put in more effort for less results.
And when you think about that concept in terms of a workout, ain’t nobody got time for that. Luckily there are ways to avoid the law of diminishing returns when it comes to fitness.
How the Fitness Law of Diminishing Returns Applies
Given how HIIT classes have taken over the fitness industry, it’s common sense that we want to build the most muscle and burn the most fat in the least amount of time. And it turns out that your workout can be too long.
Take a squat, for example, says Miguel Aragoncillo, strength coach at Cressey Sports Performance. “Your first rep will theoretically be your best rep. You’re fresh, and your central nervous system is not tired or taxed,” he says. “But if you do the exercise repeatedly, by rep 100, your form will not be as good, you’ll be very slow, and you need to watch your upper back and joint integrity.”
Poor form, of course, means you’re not targeting the muscles you want to, which means you won’t get the results you’re aiming for. Plus you risk injuring yourself.
Worse, if you go too hard for too long, you may break down your muscle. While breaking down muscles is the point of a workout, you build muscle when it repairs itself post-workout. If your exercise keeps going and going, your muscles won’t have a chance to recover.
“That’s why runners and athletes use sports drinks,” says Jonathan Ross, spokesperson for the American Council on Exercise and author of “Abs Revealed.” “Carbs are your primary fuel for quick, explosive types of sports or activity. If you don’t replenish those carbs after about 90 minutes or two hours, your body can get into last-resort mode, breaking down muscle to turn it into carbs for fuel.”