Becoming fitter — a little healthier, a little stronger, a little more flexible, a little more in tune with your needs — is a worthy goal. And an attainable one, too. You don’t need to overhaul your routine. Big results can happen if you focus on very small, very manageable changes every day. Banging out some air squats instead of being idle. Giving the kids a few more shoulder rides. Paying a bit more attention to your steps. We’re not saying these will turn you into some sort of V-shaped deity. But if you choose to make things a bit more difficult in your day-to-day world and make incremental changes, chances are you’ll be surprised by their effects — and how the momentum they build leads to better, healthier habits.