I've discussed this in the context of transportation cycling at HN in the past:
https://news.ycombinator.com/item?id=16515129
> As a transportation cyclist, some people I know think I must have superhuman willpower. But the reality is that I don't own a car, don't like the bus, and live too far away for walking regularly to be practical. I structured my life so that cycling is the most convenient option.
https://news.ycombinator.com/item?id=16450267
> No excuses are valid. Don't feel like it? Doesn't matter. I don't want to ride most mornings. Cold weather or rain? Too bad, no choice still. Sick? Take a day off for your health.
> I am no more successful at maintaining other exercise in my life. I used to run more regularly, but I haven't had the time for a while. So I understand how difficult maintaining an exercise habit is. That's why I leave nothing to chance.