3 ms·

Cyclists would be an exception to your 2 miles/hour theory.

• electromagnetic 16y ago
  Yes, but only because of gearings. There'll be a similar exertion limit. One of my old bosses was at one point a pro-cyclist, until he ruined his hips and knees. His doctor actually forbid him from cycling so that he would actually stay active into his later years. All exercise will have a limit on how beneficial it will be to you. Ideally you would want to spread it out across as many joints and muscles as possible so you don't excessively wear on any of them. I'd think the amount of calories you burn a day is likely to have a greater effect on your health than simply how much you walk/cycle or weight lift. Burn the maximum calories you can but spread the exercise over as many muscle groups as you can and that will keep you feeling young.