So I did the HIIT routine that was suggested a few pages back
50 sec jog / 10 sec sprint
48 sec jog / 12 sec sprint
46 sec jog / 14 sec sprint
44 sec jog / 16 sec sprint
42 sec jog / 18 sec sprint
40 / 20
40 / 20
42 / 18
44 / 16
46 / 14
48 / 12
50 / 10
Did it on an exercise bike. It surprisingly wasn't that bad. Maybe because I did it on no resistance? I don't know. I'm open to suggestions.
I've been doing them with a stationary bike on my off days. Resistance is semi-high but still ain't that bad.
Haven't checked my heart rate though.