So you know you’re too sedentary and the birthdays keep piling up. You suspect resistance training would be beneficial. But perhaps you’re intimidated. Don’t be.

Getting started

Check with medical professionals to make sure there are no health problems that stand in your way.

Then find a gym. Larger gyms offer a social component with things to do on a day off from weight training. And Bamman suggests getting a trainer.

“It’s actually quite safe, but it does require proper progression,” Bamman said. “You have to have a good instructor who can teach the movements properly.”

Bamman, a research scientist at the Florida Institute for Human & Machine Cognition, said finding a fully qualified trainer can be tricky.

“We need more rigorous certification of trainers,” he said. “The problem is that you can go online tonight and pay $50 and get some certification as a trainer.”

Done and dusted in an hour

Bamman suggests resistance training twice a week. Three times is even better, and he recommends non-weight-training days in between. For instance, work out on Monday, Wednesday and Friday, and let Tuesday and Thursday be days of rest.

He suggests 10 different exercise movements — eight is sufficient. Do 10 repetitions of each movement. Do this three times, described as three sets. Then move on to the next movement.

When you reach the 10th repetition, you should feel you can’t do many more. If you could have done 10 more reps, you might want to increase the resistance.

Bamman says machines are better for beginners, but free weights — barbells or dumbbells — may be more effective as you gain confidence.

Before the weights, start with a 5-10 minute warmup — on the treadmill, stationary bike or elliptical machine — to get the blood flowing. You can add a few minutes on the mat for stretching and abdominal work.

Then come the weights.

“Sometimes you see people who sit on the machine, do a set and then play with their phone for three or four minutes. We like to keep them moving.”

Women may benefit even more than men

Women may benefit from resistance training even more than men because it’s a way to fight osteoporosis, the loss of bone density.

“Women are on a disadvantaged trajectory for bone loss, particularly in susceptible areas such as the hips and lower back,” said Bamman, who completed his doctorate at the University of Florida College of Medicine.

“But the strength-training benefits for both sexes are really important. There are no sex differences in the ability to respond. In gaining muscle mass and strength in untrained people, men and women track the same.

Yasuko Kuroi is 72 and started resistance training about 20 years ago.

“I saw the men in the gym and thought I could do that, too,” she said, speaking at a municipal recreation center in Tokyo.

The body demands work

In a few words: Use it or lose it.

Bamman cautions against pampering yourself and criticized even health care professionals “who baby seniors.” Of course, common sense is required.

“Our human body is a demand-based system,” he explained. “If you chronically impart a low demand on the body, we have adaptations to low demand. That’s why we lose muscle mass, that’s why we get weaker. We’re not demanding much.”