Hi everybody

I was wondering, do you think that you get the same benefits from two 20/min workouts a day as you would from one 40/min workout? I find it a lot easier to do the 2 shorter workouts, I think my mind dreads a 40/min workout more and I am less likely to do it then. I thought I read before that you need to work out over 20 mins before your body starts to burn fat? Does anyone know if this is true? TIA!