Develop a Competent Core
Men are famous for working through the pain. That pop you heard while exercising? No big deal. The twang you felt in your back while raking the leaves? It's nothing. The sharp jolt in your knee when you landed after making that last basket? It'll pass.
This approach to fitness just might work while you're in your 20s. But once the 30s hit, things need to change. This is not only because you want to demonstrate that you've gotten wiser as you've gotten older, but also because your body will actually begin to lose coordination and strength during your 30s. That's not to say you shouldn't work out. In fact, if you don't, you stand to lose 10 pounds of muscle during the decade [source: Men's Health]. But now's not the time to focus on how much you can bench or curl. Instead, focus more on strengthening the body as a full unit.
One of the best ways to do this is to incorporate more core and stability exercises -- such as the front and side plank, one-legged squat, and pretty much anything involving those giant exercise balls -- into your weekly routine. Such an exercise routine will protect your joints, strengthen connective tissue and may even deliver that all-illusive six-pack.