Staying (strategically and appropriately) active is one of the most valuable tools we have. The more we sit, the faster we age. The more we move, the stronger our metabolism. And the better we feel, think, learn, and remember.

Different types and intensities of exercise affect our physiology differently. This is especially true when it comes to preserving muscle mass and metabolic might as we age. Intense exercise is more effective in preserving our BMR (basal metabolic rate) and preventing muscle loss. Lower-intensity activity serves an important purpose but doesn’t do as much to support a strong metabolism.

The definition of high-intensity is, of course, relative. And it can vary greatly from athlete to athlete and person to person, depending on how an individual’s body has adapted to any given form of exercise.

One of the best ways to determine your current state of physiological fitness (it’s even better than doing a VO2 max test) is to perform a simple hand grip test. The stronger your grip, the slower you’re aging. If your grip is strong, your entire body is strong; you have lots of lean body mass, strong connective tissues, a dense skeleton, and the motor skills necessary to coordinate the combined use of all these things. It’s not too difficult to see why strength and resistance training becomes a priority with age.

Regardless of your chosen sport or the level at which you compete, it’s important to lift heavy things on a regular, ongoing basis. You don’t need to spend hours and hours at the gym. You can accomplish a lot by investing 30 to 45 minutes, once or twice a week.