I do pushups, situps, pullups, and run after warming up with Army PT drills.
I can do those exercises anywhere, anytime.
I'll hit the weights as soon as I heal an injury of mine, but that's the best way to get SWOLE!
I've used powders, but they were all weight gainers. If you're trying to lose, that won't help.
All supplements aside, I gained 20 pounds of muscle in 2 months at BCT just from exercising every damn day and eating 3 square meals of healthy, down home southern cookin'.
Good luck with your goals, Dave!