The fitness regime I got more out of than anything else has been interval training. I worked out with weights for years and occasionally would do some cardio.

The fitness regime I got more out of than anything else has been interval training. I worked out with weights for years and occasionally would do some cardio. I think the logic was... cardio doesn't make you look good in a swimsuit like lifting weights does, and at the time impressing ladies and intimidating other guys was priority (lets don't lie to ourselves about motive here!). Then, I got a little older and impressing ladies became less important and general health and a sense of well being more important. I read an article that made me realize many of the same principals of weight training can be applied to inner muscles as well. A knowledgeable person wouldn't go to the gym and lift 5 pound 300 times and expect to get stronger. Instead they would lift 80% of what they could 5 times in sets. This is what builds strength. The same principal applies to interval training for heart and lungs. Rather than getting on a treadmill for 45 minutes at a slow slog you push yourself to a percent of max heart rate for like 3 minutes in sets (the same as weight training). The workouts don't take that long and I found they greatly improved my feeling of health and general vigor. There are a number of studies on the benefits of improved heart stroke volume etc. from interval training which I can't find at the moment.