So I recommend starting with the bike unless you are an experienced runner that
knows your body well.
In addition, here are three more key points about the bike.
a) Stick to the upright version if possible. When using a recumbent bike for intervals,
your hips tend to rock too much and your body tries to get into awkward positions
in order to push hard against the resistance. That's my experience. The upright
bikes are set up better for intervals.
b) For intervals, increase the resistance against your pedalling, and not the speed
of your pedalling. I don't like high RPM spinning. I think you'll get more results
and do more work when you keep the RPM between 80-100 and work against a harder
resistance.
Forget that high-RPM spinning stuff...I find it is rough on your hips and knees.
c) When on the upright bike, sit as upright as possible for the recovery intervals
or even stand for some of the work intervals. Just avoid the "rounded over"
posture as that can be hard on your low back.
So the winner is...The Treadmill.
The treadmill can burn 16-20 calories per minute of exercise during your workout.
That's a big burn, but of course only advanced fitness levels can achieve that -
but hopefully you fit that category now or you will someday with consistent training
and nutrition.
Some tips: Don't go crazy with the incline (as that can lead to tight calves), but
if you are able to run at more than 10mph, use a 1% incline to help offset the need
for speed. The last thing you want to do is end up in a crazy video on YouTube flying
off the end of a treadmill into an elliptical machine.
So as with all types of sprinting, be careful.
Honorable mentions go to...The Rowing Machine and Stairmaster...these can be used
in place of other machines for variety and are still effective.
Better yet, if you are able, use your body as the best fat burning machine. I highly
recommend bodyweight circuits for interval training. These are fun, effective, and
perhaps even better at sculpting your body.
I really like bodyweight interval circuits for advanced fat-burning, plateau-busting
workouts. If you're stuck, you'll benefit from bodyweight circuits.
Sincerely,
Craig Ballantyne, CSCS, MS
Author, Turbulence Training