I was a terribly awkward youth. I grew in "spurts" and always seemed to have "two left feet" As you might imagine, I did poorly at sport.
I grew up in an age, when PE meant one thing; competitive sports. Being the last one picked, the kid who scored on his own team's goal, the guy who couldn't catch a pass if his life depended on it... Games of Sport are meant to be fun, but for me they were little more than exercises in dread. Those experiences (and the social repercussions) soured me against sport in general. My physical health suffered, I was weak, overweight and under-socialized.
It wasn't until I was a teenager and had had enough of being the "wilting lily" that I discovered that physical activity, fitness, and self-improvement need not be accessed merely through competition with my peers. I took up weight training, cross-country running, diving, and yoga... all sports of a more solitary nature yet fantastic for physical health.
I soon discovered that being fit feels really good, and that feeling good is very attractive...
I got lucky, just stumbling upon solutions, but I remain an active advocate of non-competitive sport. There is plenty to choose from, even many that are ostensibly competitive yet in practice turn out to be more about individual goal setting like; skiing, skate-boarding, swimming, track and field, rock-climbing...
still, I cant recommend yoga enough. it is probably the one "sport" that transformed me the most. poise, strength, co-ordination, self-esteem... plus it is a great way for the less-than-athletic person to get their start.