Sprinting is
the single most beneficial workout for aerobic/anaerobic capacity. I would suggest starting with a moderate running program though for a week or two just so you get your body used to running. Sprinting, when done correctly, should make you want to kill yourself rather than keep going.
Next sprint- as fast as you can for 40 to 60 seconds. If you find you can run that fast for longer, your not running fast enough.
These are some good ideas here. However I think sprinting at 100% for 40 - 60 seconds is a bit unnescessary, and for a beginner might be completely impossible. Try 20 seconds to start with and slowly work up to 30 seconds.
My suggestion would be to use 100m intervals instead. You can use two methods for this:
1. Sprint at 100% intensity.
2. Walk back.
3. Repeat 4 - 6 times.
-OR-
1. Sprint at 80 - 90% intensity.
2. Jog back.
3. Repeat 4 - 6 times.
Note, the textbook I use for conditioning suggests that sprinting more than 600m in total leads to diminishing returns. So 400 - 600m is the optimal total distance in a sprinting workout.
There is also the method of Tabata intervals which another member on this forum introduced to me. So far I've only been using it for a week but already I've noticed a big difference from only a small amount of training, and is good if your legs are too weak to run on a regular basis.
On a stationary bike:
1. Warm up (5 minutes).
2. Cycle as hard as you possibly can for 20 seconds (aim for 450 watts).
3. Rest for 10 seconds (aim for 75 watts).
4. Repeat steps 2. and 3. eight times, for a total of 4 minutes.
This site provides a better explanation of the above:
Good luck with your training, it might seem impossible at the start but if you have commitment you will achieve things you never would have imagined you were capable of.
