If you've passed the half-century mark, it's likely that your body isn't bouncing back like it once did. Your lower back might be feeling the pain of yesterday's raking session, your left foot might still ache from rolling it while trail running back in July, and then there's the knot behind your right knee from a skateboard incident more than a month ago.
But you can't give up, especially if you want to do the things you love — bicycling, hiking, running, golf — well into your 60s, 70s and 80s. Here are some ways to stay in the game:
As we age, warming up becomes more important, according to Laura Cisneros, founder of Urban Animals boot camp in Austin, Texas.
"Tissue gets less elastic as we age," she said. "We warm up with the idea of gaining maximum flexibility. Once the muscles are heated up and more pliable, you want to increase that range of motion, which is another thing we lose as we get older."
She incorporates medicine ball work into many of her workouts, because they allow you to train at maximum range of motion with velocity and increased flexibility. Then, it's on to strength work, which helps boost creation of energy-producing mitochondria in our cells.
"That's the nirvana for fighting off aging, from the muscle and movement perspective," she said.
Cisneros recommends spending about 40 percent of each workout on flexibility and mobility, then splitting the rest of the time between cardio work and strength training.
Jim Owen, author of "Just Move! A New Approach to Fitness After 50" ($22.99, National Geographic) has a simple message: Quit sitting so much.