Tim Caso is 58 — and he's squatting weights of more than 300 pounds.

"There are all kinds of benefits," says the author of Weight Training for Old Guys, including the building of muscle and burning of fat more efficiently, better bone density, and higher metabolism.

Plus, you'll live longer.

A 2016 Penn State University study examined data from the 1997-2001 National Health Interview Survey (NHIS) of death certificate data through 2011 and surveyed more than 30,000 adults 65 and older. During the survey period, more than 9 percent of older adults reported strength training at least twice a week.

Respondents were followed for 15 years.

Older adults who met twice-weekly strength-training guidelines were found to have a 41 percent lower chance of cardiac death and a 19 percent lower chance of dying from cancer.

How to get started?

"If you've taken 20 years off from the gym, do a few months of circuit training first and build some strength before you get into the complicated moves," said Caso, who lives in Chalfont. "The trend among baby boomers going back to weightlifting is partly because of the popularity of CrossFit, but also because its low impact."

He and other boomers such as Leo Totten and Bob Giordano say older men and women shouldn't miss out on the benefits of weight training and lifting. Giordano recently went to his doctor, who told him "you have the bone density of someone in their 30s."

He's 66.

Giordano and Totten have also coached what are known as "masters," weightlifting nationally and internationally, and, increasingly, they're seeing men and women in their 80s, and even into their 90s, competing professionally. Totten, 65, runs the East Coast Gold weightlifting team. He made the 1984 Olympic team, and today he coaches, speaks at conferences around the world, and promotes weight-training among Baby Boomers.

East Coast's "Masters Team just competed in Savannah and on the men's team, the oldest competitor was 77. Another is 73," he said. The next oldest age group competing is 80-84 years old, said Totten, a resident of Littlestown, Pa. The oldest woman on the Master's team was 63.

Do you have to be in peak physical condition to get started?

"No, you don't have to be 100 percent. Some people have more power than others, some have better technique. Flexibility, you may lose as you get older," Caso added. Terrence Fenningham, owner of two CrossFit gyms in center city and Willow Grove, persuaded his 64-year-old father to start training three times a week after years of inactivity. "We call it functional fitness," Fenningham said.

Douglas Schrift, 61 and founder of ElderGym.com, a website for seniors looking to exercise, recommends women start with 2-pound dumbbells, and men with 5-pound dumbbells, resistance bands, or hydraulic machines such as those in Curves gym. "Whatever your strength training is, it should relate to your daily life. If your bedroom is on the second floor, focus on strong legs. If you have high cupboards, work on your shoulder and arm strength."

Giordano, an administrative law judge in New Jersey, was an elite lifter who won a spot on the 1980 Olympic team when the U.S. boycotted the Moscow Games. He works out at Mission Fitness-CrossFit West in Livingston, N.J., three days a week, sometimes more often, and sometimes his wife comes along.

"Older people should be doing weight-bearing exercise. Your body reacts to stresses, and if you put weight load on, your body sends messages to build muscle and skeletal system," Giordano said.

His father "never exercised. In his 70s, he became less ambulatory. I vowed I would never be like that. Yes, things ache in the morning. And I wish I could say it eliminates pain, but at least I have aches and pains from working out – not from aging," Giordano said.

Both Giordano and Caso said free-weight training is the best way to start — with supervision.

"You shouldn't do stuff you see on TV. You have to have a trainer, because if you don't handle the weights properly, you can really hurt yourself," says Caso.

What about the rest of us? Giordano also recommends swimming — the ultimate resistance and weight-bearing exercise.

"You're using your body and the resistance comes from the water and doesn't hurt you."

Start with ordinary light weights around your ankles while walking, or carrying small weights while strolling. Even a broomstick with weights will do.

"Start with circuit-training in the gym, develop a degree of strength for three to four months. Then, if you want, you go to the barbells. An older body can't do the volume. Instead of doing seven sets of five repetitions, an older body can do three to four sets. Otherwise, you risk overuse injuries, rotator problems, knee problems. Three sets of heavy exercise, a lot of times, is plenty."

Caso injured himself a year and a half ago.

"I was doing too many weights for too long. I ruptured both tendons squatting. I was hospitalized and lost 15 pounds. I got out and did rehab. Then, I took a few dumbbells and walked up and down the stairs."

And ladies? As women get older, their bones "honeycomb. You're losing estrogen, but lifting actually keeps your bones strong. You won't get bulky. Women never get big and bulky doing these compound exercises. They just don't have the testosterone."