I am running for 20 minutes a day on a treadmill, I have heard, that everyone has a certain percentage for effort that they should be trying to reach that is healthy for them... which depends on age, fitness etc. I think it may be connected with heart rate??


I don't know how much 'effort' I should be putting into my exercise when running... or how I would know if I were. I am 14 years old, 5'5'' and 100 lbs. I have already lost almost a stone due to change of lifestyle (i.e. becoming more healthy) and I do not wish to lose any more weight, just maintain... I have been running for 20 minutes a day for a couple of months on a treadmill and before that outside for another month or so for the same time.

Could anyone tell me what percentage I should be aiming for and explain to me exactly what it means?


Thank you very much.