Circuit Weight Training

Griff commented on something I was just thinking about: the ability of weight training to increase aerobic power.  One way to do this is circuit weight training, which, for example, LL Cool J has had great success with.

I do think that circuit weight training, or even regular weight training done with little rest, can improve cardiovascular fitness.  I don't however, think it can improve aerobic power (measured by VO2max, which isn't a perfect measure anyways) as good as intense cardiovascular work.

Also, it seems to confuse two somewhat separate objectives.  For me, weight training is about maintaining or increasing lean mass, while cardio is about building aerobic power.  By taking an adequate but not too long of a rest between sets, I can focus on lifting heavier weights.  With shorter rest periods between sets, I am able to generate less intensity on each set and not provide the best stimulus for building muscle mass.

If a person is in a time crunch, I think circuit weight training can do a good job at building some aerobic power and some muscle mass.  But if a person has more time, I think they would be better off splitting the two, utilizing longer rest periods during weightlifting for more lifting intensity, and performing high-intensity cardio like interval training for more gains in aerobic power.