When should you be most serious about working out: during the bathing suit years of 20 to 30, during the prime family and career years of 30 to 50, or after 50?
While looking good in a bathing suit is nice, and being able to keep up with the kids and look trim at the office is helpful, it's later in life that working out is the key to having a better, higher quality of life.
The trembling, hesitant movements by some people in their 70s and 80s are not caused by their age, but by the wasting of unused muscles. The scientific term is "atrophy," and it's something that happens to muscles that are not used, whether you're a senior citizen or a teenager.
Here's an example, using one of the most common causes of disability in later life: the wobbly walk that can cause a hip fracture.
Start with that familiar Simon & Garfunkel song, "Old Friends." There's one line; "How terribly strange to be 70." So if you're not already 70, imagine the time when you will be. Because if you live long enough, at some point you will be 70.
You can be active and healthy, riding your bike and even inline skating and snow skiing. Or you can be incapable of any extensive physical movement, unable to even think of going for a run or a bike ride. Countless studies have proven that the choice is yours.
No matter what your age, if you sit around watching television or reading, it soon gets uncomfortable to move your body. If you give in to that discomfort and never push yourself so that your muscles get pumped up with blood, your muscle fibers will shrink and you'll become weak. As you weaken, your balance suffers, because balance is learned, and powered, by strong muscles.
So here you are at 70 (or older), with little strength and without good balance. You have to walk slowly to re-balance with each step. Meanwhile, the lack of movement allows your proprioception to atrophy.
Proprioception is actually like a sixth sense. It lets you "sense" where your body is in space. You can sense just how much you need to lift your foot to step up on a curb, just how far you need to reach to grab the salt shaker without knocking it over, how to hold your body when bending to pick something up off the floor so that you don't overbalance and tip over.
There are proprioreceptors, small sensing organs, throughout the body. They let the brain know where each part of the body is in relation to the environment. Proprioception is developed and improved with practice. If you've never hit a baseball with a bat, you won't be good at it the first time you try. But if you keep practicing, your reactions will improve so that you can hit the ball with a lot more accuracy. The "sensing" of where your body is, and where it needs to be, stems from proprioception. That's why practice makes perfect.
But if you sit around, allowing your muscles and balance to atrophy, your proprioception will decline as well. So here you are in your 70s, weak and with feeble balance, unable to sense where your body should be to stay upright. It's only a matter of time until you take a nasty fall — perhaps with the disabling broken hip that alters the rest of your life.
Now the good news: none of this has to happen. Much of the weakness we blame on age is really just atrophy. If you consistently make the required physical effort to keep from losing muscle strength, to maintain your balance and proprioception, you will stay physically capable as you age.
A daily walk of at least half a mile; a workout routine of regularly moving each of your joints and doing some resistance work; 10 or more minutes spent stretching every day. All of that will keep you strong and vigorous, younger than others of the same age. Don't wait until you're 70. Start now, whatever your age, and you won't decline nearly as much as you get older.