“You can’t get five people to agree on what’s a healthy diet,” primary care doctor Robert Sallis says in “Rx: Exercise,” an article written by Neha Pathak, MD, for WebMD.

“But when you talk about physical activity levels, there’s no argument. [The guidelines] are the same in the U.K., Australia, Europe, on and on and on.”

The guidelines (which you’ve read more than a few times before, I’m sure) also appear in Pathak’s article. To work up to the point where you’re doing 150 minutes of moderate aerobic exercise or 75 minutes at a higher intensity level in a given week, along with two weightlifting sessions.

Sallis also explains that in doctors’ manuals on how to treat just about any sort of health problem - like back pain, arthritis, cancer, and heart disease - exercise is one of the first suggested courses of action. But “we always skip right over that to the first drug.”

But Sallis really shouldn’t include himself in the “we.”

When he sees patients, Sallis asks if and to what degree they exercise and records their responses in the same way he records heart rate, blood pressure, and body weight. If need be, he does something else before prescribing drugs.

He prescribes exercise.

While Sallis, who chairs the American College of Sports Medicine’s Exercise Medicine Initiative, deserves to be commended for this, I’ll save my kudos you - if you’re doing what you should and writing your own exercise prescription. But not many are up for congratulations, according to the Centers for Disease Control and Prevention’s age-group statistics on exercise.

While slightly more than one out of every three Americans between the ages of 18 and 24 engage in sufficient cardio and strength training, for those 25 to 44 it’s slightly less than three out of 10. The ratio for those aged 45 to 64 drops to about two out of nine, and for those 65 to 74 it’s less than one in six.

The rate for those past the age of 74 is one in 12.

Keep those proportions in mind as you consider this jump in salary: from $2 million to $6 million per year. According to a 2018 Sports Illustrated.com article, that’s the difference between what Colin Cowherd used to make working for ESPN and now makes at Fox Sports by hosting “The Herd,” a sports talk radio show simulcast on television and radio.

A good deal of Cowherd’s success - which obviously led to the tripling of an already seven-figure salary - I believe, comes from how he views his job.

“I don’t need to be right,” Cowherd has said on his show more than once. “I need to be interesting.”

I bring this statement to light because it would be good for you to adopt a similar saying. “I don’t need to be right. I just need to be exercising.”

While following it certainly won’t triple your wealth, it will surely do wonders for you health - and Cowherd’s first sentence alludes to why you need no doc to prescribe you exercise.

Though I would never tell you to begin an ambitious exercise regime if you’re middle aged or older and have been sedentary for longer than three months (or in overall poor health regardless of age) without consulting a doctor, you don’t need to see one to start exercising in virtually any other situation.

When you exercise for improved health instead of improvement in a given sport, the plan is simple and practically foolproof, so Cowherd’s I-don’t-need-to-be-right observation is spot-on. But whether you choose pilates, tai chi, yoga, walking, swimming, biking, weight training, using an elliptical trainer, running on the roads, or sprinting on the track, always begin conservatively and mindfully.

Be as mindful of the sensations in your body as a broker is of the fluctuations in the stock market. Discomfort is okay; pain is not.

Being sore the next day is okay; not being able to alleviate it during the following day’s warmup, however, is not. Use that discomfort as the signal to stop and spend the rest of your workout time stretching and luxuriating in a hot shower.

And don’t hesitate to change the prescription you’ve written for yourself regularly. Your body and brain quickly acclimate to a specific workout.

It’s part of the law of diminishing returns. After four weeks or so (and definitely in eight), doing the same workout with the same degree of effort doesn’t benefit your cardiovascular system and targeted muscles - or burn the same number of calories - as much as it did before.

So unless you love a sport and want to compete in it (whether that’s against others or solely against yourself), consider cross-training.

It not only slams the door on the law of diminishing returns, but it also opens the one that keeps you from feeling trapped and creating burnout.