Robert De Niro, 69, and Sly Stallone, 65, are training for an upcoming boxing film, "Grudge Match," about aging rivals heading back into the ring.
Just the idea of those two shirtless in trunks makes us think about the importance of preserving muscle mass as you age. After all, even the fittest athletes lose muscle tone with passing decades.
Here's why. You don't use your muscles as much as you used to; plus, you have lower levels of growth hormone, which is good for preventing cancer spread, not so good for muscle growth.
If you add to that lower levels of vitamin D-3, an imbalance in the acid-base content of foods you eat (more about that in a minute) and lack of enough protein and vitamin B-12, you're going to lose muscle tone.
But you can fight back.
To build muscles you need about 68 grams of lean protein (skinless poultry, salmon, trout) a day if you weigh 150 pounds; a 1,000 IU supplement of vitamin D-3 daily, 1,200 IU if you're over 60; and 25-100 mcg per day of a B-12 supplement if you're 65 or older.
And about acid-base balance: Too many acid-producing foods (100 percent whole grains and lean proteins) and not enough veggies and fruit (they're base) weakens muscles and bones. So aim for balance by making sure you eat nine servings of produce a day.
You need strength-building exercises - done for 20-30 minutes two to three times a week - combined with walking 10,000 steps a day! Realage.com offers 17 nifty resistance-band exercises.
Mehmet Oz, M.D., is host of "The Dr. Oz Show," and Mike Roizen, M.D., is chief medical officer at the Cleveland Clinic Wellness Institute. To live your healthiest, visit sharecare.com. Distributed by King Features Syndicate, Inc.