I recently bumped into two articles (excerpted below) referring to studies that correlate exercise and fitness to your genetic makeup. One suggests that some people have genes that cause them to respond positively to exercise and its results—increased heart rate, sweating, feelings of exertion. The other article says that some people can do the same workouts as others, but not have the same physical or fitness results. This also is attributed to genes you have or don’t. What a bitch! You do all that work, and it doesn’t show more muscles? Hard for me to believe.

But if you can just get past that initial resistance, there is hope for anyone.

…even the sedentary among us can build up a physiological desire to exercise, just by sticking to a consistent routine.

“When you ask these people, did you like it the first time, they’ll say God no, it was awful, I was nauseous, I was sore for four days–they’ll tell you all kinds of horror stories,” says Geralyn Coopersmith of Equinox Fitness. “And if somehow they were able to push through the initial period, invariably they’ll tell you, oh my God, I can’t imagine my life without it.”

…The way that exercise affects your mood during and immediately after a workout is perhaps the most crucial predictor of whether or not you’re likely to keep doing it.

“Two people might feel the exact same pain running up a steep hill. One of them says, this is horrible, I don’t want to do this. The other one says, I’m building so much muscle, I’m so excited to be working this hard, I can tell my body’s getting stronger,” says Dr. Angela Bryan. “So it’s the interpretation of those physiological responses that seems to be pretty important in terms of how people view their exercise behavior.”

“People who exercise, by and large, they talk about doing it because they enjoy it. It’s not, ‘I’m doing this so I won’t get cancer in 50 years,’” she says. “That’s why we’re looking at some of the underlying genetic and physiological variables that might be associated with that intrinsic motivation. Because if we could figure out who’s got more of it and who’s got less of it, then we can potentially develop different interventions for those kinds of people.”

…Scientists long have known that when any given group of people faithfully follows the same aerobic workout routine, some increase their cardio-respiratory fitness substantially, while an unfortunate few seem to get no benefits at all. But what, beyond the fundamental unfairness of life, makes one person’s body receptive to exercise and another’s resistant? According to the new study, which will soon be published in The Journal of Applied Physiology, part of the answer may depend on the state of specific genes.

Dr. Claude Bouchard and his colleagues used a tightly controlled exercise intervention on nearly 500 subjects over the course of five months. They discovered that the extent to which their subjects did or did not become more fit was significantly determined by exactly 21 tiny variations on snippets of their DNA…