You can blast your chest with the hardest pushup variations known to man one minute, and do single - leg burpees for lower - body power or conditioning the next. (onnit.com)
Finally, if you're looking for more variety, and are keen to hone in on your muscle development, it would be worthwhile to tackle the hundred pushups program performing advanced pushup variations that will really provide a challenge. (hundredpushups.com)