Wired: Be More Than You Can Be
tells of a number of new things that DARPA is doing to enhance the soldier of the future. For example, there is the "glove" that you can put on, and it will either dramatically cool or heat your body, as desired. It turns out that one of the big problems with working out is muscles overheating, and not fatigue, per se, and so by coooling the body this way, endurance can be significantly increased.
So, in another decade or so, we can expect our soldiers to be stronger and faster, be able to think faster and better, easily survive and operate in extremes of heat and cold, and maybe even go into hybernation when wounded. All thanks to DARPA adding biological systems to its mandate.