Aerobic vs Resistance Training: Which is Better?

We're just human so we always want to know what's best.  After all, we don't want to waste our short lifespan and precious resources on something that's not worth the effort.  This is known as obtaining maximal value.  So it is with exercise.  Let's first agree that exercise is a good thing and that while we recommend 30min/d of moderate intensity activity, a recent study has demonstrated that even 15min/d gets us some benefit.  The big question then is whether aerobic exercise is better than resistance (strength) training, or is it vice versa?

Well, in an 8 month study published last month, researchers randomized 196 overweight adults to either resistance training three times weekly, aerobic training at 12mi/week at 75% VO2max, or a combination of both.  Only 155 managed to finish the program.  But interestingly enough, those who engaged in aerobic training appeared to benefit the most by losing more visceral and subcutaneous fat than in those who engaged in isolated resistance training alone.  Surprisingly, at least for me, those who engaged in both activities showed no benefit beyond those who skipped out on the resistance sessions (although they were still better off than those who did resistance training alone).

Besides weight (fat) loss, those who engaged in aerobic activity also improved their insulin resistance and liver function tests.  Thus, the authors concluded that aerobic exercise is more time efficient and efficacious than resistance exercise in reducing body fat, both subcutaneous & visceral.

However, I would be loathe to tell my patients not to lift weights or perform calisthenics.  After all, without adequate core and extremity strength, how would we transfer out of bed and get off a chair or toilet seat?  How would we put away the pots & pans and plates & glasses above our heads?  Without resistance exercise, how would we fight off sarcopenia or muscle loss?  Finally, let's not forget that this is a small short study such that I would want more randomized controlled trials to corroborate its conclusions.  And even then, I would posit that fat loss is not the be all and end all goal.  What good is losing our visceral fat if we become frail and weak?