But don't be lulled by such extreme scenarios. A number of studies find that training four or five times per week provides little or no benefit beyond exercising three times. No exercise is perfect. To help you figure yours, here's a rundown of some random pluses and minuses. Exercise doubles as transportation.
Good bikes are cool.
Equipment available for indoor workouts. Yahoo motorists make road riding scary if not dangerous. Need minimal equipment. The most spiritual of exercises, if you believe the hype. Impact injuries common.