I've read a lot of stuff about this online, but I couldn't find anything useful for me... I usually do cardio every time (try to be about 4-5 times a week), 20mins treadmill and 20mins bike. I have no idea what my heart rate is on the treadmill, but I assume it's about the same as on the bike (as I feel as tired). On the bike I choose a program that has intervals and my average HR is always about 162 (sometimes even more), so that counts as a high intensity workout, I assume (I'm 22 years old). When I'm on the treadmill, I usually go with a steady speed of about 7.5km/h (which is very slow, but it really kills me every time). I've read that it's better to do interval cardio training but... If my HR is about, say, 160 steady, why should I do intervals?? It would only take me longer, and I wouldn't achieve that much of a difference in heart rate... or am I wrong? Thank you!!