> But if the goal is some sort of performance improvement (specially in endurance sports - cycling, running, etc.) It probably isn't, for most non-athletes and

> But if the goal is some sort of performance improvement (specially in endurance sports - cycling, running, etc.) It probably isn't, for most non-athletes and people who don't have a sport hobby. > yes, intervals are definitely useful to push the body further, but only after a buttload of cardio I definitely won't be doing "a buttload of cardio", so we're back to square one - what is a good 80:20 heuristics that balances time investment, discomfort and results.