Similar to what the others have said. I will add that I generally walk every day for 20-60 minutes (1/2 hour is average), regardless of whether I am also biking that day. 2-4 times/week, instead of biking (road or indoor intervals) I will do some combination of: strength training, core work-out and/or yoga - even if it's only for 10 or 15 minutes. I find that my body lets me know when I have been biking too much and not giving it enough of what else it needs. For example, my lower back will get sore after a ride if I have neglected my core too long and my hip flexors cry "uncle" when the yoga is neglected.