I was doing some thinking about the benefits of resistance versus aerobic exercise. What's strange for me is that even though I've gained some muscle this year, it has had no effect on my day-to-day life. I don't feel any different. I suppose the added muscle is functional, but in a non-physical job (like mine) you don't really utilize your muscles much on a daily basis.
Conversely, when in the past I've been in better aerobic shape via running/interval training/dancing, I've felt better and had more energy on a daily basis. This is somewhat in line with the recent paper on how the aerobic system truly underlies the capacity of the human system.
I remember in the 90s there was a big anti-aerobics push, and there was the notion that strength training provided all the aerobic training that was necessary. This is entirely false in my opinion, mostly because of the evolutionary implications. Roughly you could say that in terms of hunter-gatherers, the aerobic system provided locomotion (running, walking, etc.), and the muscular system either supported this locomotion or was used to move heavy objects. But it would seem very probable that the locomotion system was dominant. How can you acquire game by standing in one spot? If a load was too heavy, you could always get help to move it. But if you just sat around in camp and expected others to go hunt for you, I'm not sure that would take you very far.
I put in a good aerobic workout (along with weightlifting) yesterday, and I definitely had more energy than usual today. I will probably start putting more emphasis on aerobic work, if only to gain the psychological benefits.