Exercising for fuck's sake - Stamina

For stamina, do interval training.

Rarely are you going to be having sex at a steady rhythm for long stretches like you would jogging on a treadmill...unless your just bored and chances are your partner will be as well if you keep it up. Sex is a series of climbing peaks reaching to an orgasm, the climax of which is best handled by some serious thrusting power, a sudden burst to drive her over the edge. You don't want to find yourself winded after only her first. Interval training more closely resembles what you will do during sex. At least, it will resemble the intensely wild and mind-numbing sex that can drive a woman crazy and get her off in a big way.

Interval training is really rather simple. For example, my typical interval training routine would be a 5 minute warm-up on the treadmill followed by 20 minutes of intervals then 5 minutes cooling down. During that 20 minutes I will sprint for 30 seconds at top speed then walk for 1 minute and so on and so forth. I'll do this three times per week.

This conditions your body in a way that is great for sex. Your cardiovascular system improves the most through this kind of exercise. The number of blood vessels in your muscles increase allowing your body to better distribute oxygen to the muscles, your muscles start to use lactic acid as a fuel source, and the heart's ability to pump blood where it is needed *clears throat* increases. As an added benefit you burn more calories doing interval training than you would with a longer lower intensity aerobic workout so if you are trying to shed the pounds and trim up this is your best bet.

A word of caution on interval training though....it is intense. If it isn't then you either have the heart of race horse or you aren't doing your sprint fast enough. If you are not used to doing aerobic exercise then you will want to start off with a shorter span of intervals (5 or 10 min) and/or shorter intervals (10 sec instead of 30). Work your way up to the 20 minutes if that is reasonable for you to achieve and be careful about it. Aside from a heart attack there are myriad ways to injure yourself doing something as simple as running. Make sure you have a good feel for what you can handle before you push yourself to the breaking point.

Lastly, don't do interval training every day. You should toss in some steady cardio in between your interval days, at least a couple times per week, so that you don't end up over training and so that you still get the endurance benefits of steady cardio.