You’ve been exercising religiously for weeks, but you’re not seeing results. You’ve tried High Intensity Interval Training (HIIT), the Tabatha method, Crossfit, Intensity, or anything else that promises to “shred” or “destroy” your poor body. When you voice your frustration, your lean mean personal trainer accuses you of sneaking in treats, or not doing enough cardio, or not pushing yourself hard enough–which is maddening, because you’ve been sticking with all the cardinal rules.
If this sounds familiar, here’s a bit of science that proves you’ve been wrongfully accused. According to studies, individuals report extremely varied cardiovascular improvement (measured in VO2max) as a response to aerobic training. VO2max stands for maximum volume of oxygen used to metabolize energy during exercise. Higher VO2max means a greater amount of energy efficiently used by the body–which means a greater caloric burn during exercise. (Elite athletes often report more than double the VO2max of average people.)
Subjected to the exact same aerobic training over a period of time, people experience 19% increase in VO2max on average. But about 5% of people experience very little improvement to their VO2max (0-5% increase), while the top 5% experience an increase of 40-50+%! VO2max gain is also highly heritable (47% heritability). Thanks, Mom.
But there is a silver lining to this madness: while both initial VO2max and the gain in VO2max are highly heritable, they are controlled by different genes and show no correlation. This means your initial fitness level has no bearing on just how much you can gain from exercising. (Even if you are a couch potato now, you could be one of those lucky ducks who get a 50% VO2max boost from training!) And if you’re truly struggling with disappointing results, get your VO2 tested at your local sports performance center, where they can measure your metabolic rate and recommend your own cardiovascular “power zone” for most efficiency. Assessment cost starts around $115, but it’s definitely a worthy investment for your peace of mind.