NEW YORK – Dr John P. Porcari is a bit of a reality-television show junkie.

When he wants to work out, the retired professor of sports and exercise science from the University of Wisconsin-LaCrosse watches Alaska: The Last Frontier (2011 to present) or Naked And Afraid (2013 to present) while bouncing on a mini trampoline.

The global market for trampolines is anticipated to rise to US$4.1 billion (S$5.4 billion) by 2027, up from an estimated US$2.9 billion in 2020.

Despite its exploding popularity – fuelled in part by the pandemic, when demand for mini trampolines skyrocketed amid gym closures – the trampoline still seems more like a kid’s toy than a legitimate workout tool.

But a growing body of recent research suggests that trampolining (also known as rebounding) is an impressively effective, efficient mode of exercise.

In one 2016 study Dr Porcari conducted for the American Council on Exercise, 24 college students jumped on mini trampolines for six months.

During each 19-minute workout, men burned an average of 12.4 calories a minute, while women burned 9.4 calories a minute, similar to running 9.7kmh on flat ground. Yet, the participants rated their effort on the trampoline as lower than one would expect for that level of exertion.

In short, Dr Porcari said, they were having too much fun to notice.

Though there are few large, high-quality studies on trampolining, the studies that exist suggest it improves balance, cardiovascular fitness and pelvic-floor musculature, all while being gentler on the joints than higher-impact forms of exercise.

Here is what the experts say about trampoline workouts and how to get started.

Improve your balance

In addition to being a cardiovascular workout, bouncing is “fantastic” for balance as it builds muscles in your feet, ankles and calves, Dr Porcari said. This is particularly important as people age and their risk of falling goes up.

Another study, published in 2011, suggested that jumping on a mini trampoline can specifically improve dynamic balance – the type of balance required when you are walking, climbing stairs or standing in place. In older people, improving dynamic balance can lower the risk of falls.

Dr Porcari said even a simple routine of five or 10 minutes three days a week, alternating between jumping on one foot and two feet, can improve balance.

“Because of the relatively high intensity of trampoline exercise, you can get away with fewer minutes” than, say, on the elliptical machine or treadmill, he said.

Support your pelvic floor

Trampolining may offer unique benefits for older women, who are at higher risk than men of developing conditions such as osteoporosis and urinary incontinence.

About 70 per cent of American women aged over 60 have some form of urinary incontinence. The largest segment – 53.1 per cent of women in this age group in a recent study – experience involuntary loss of urine caused by physical activity (or laughing, sneezing or coughing) that increases abdominal pressure.

Some evidence suggests that trampolining may preserve or strengthen the muscles that can prevent this.

One study published in 2018 suggested that the pelvic-floor muscles are highly active during mini-trampoline jumping.

A not-yet-published study indicates that pelvic-floor function can be improved by rebounding. In that study, 37 postmenopausal women did 30-minute mini-trampoline workouts three times a week.

After 12 weeks, the women had better scores on urinary incontinence and higher bone-mineral density. (Their bone-mineral density returned to normal when they stopped rebounding regularly.)

Ms Anja Fricke, a graduate student at Massey University in Wellington, New Zealand, and lead author on the study, said women should start with simple jumps while holding on to a handrail if available.

Start with intervals of eight minutes of bouncing followed by two-minute breaks. To get the pelvic-floor muscles activated, Ms Fricke suggested squeezing a soft gym ball or a children’s football between the legs, then jumping by pushing off with both legs while keeping the ball in place.

Safeguard your joint health

Trampolining may also be better on your joints than exercises such as running, basketball or tennis, Ms Fricke said. Much of the force of jumping and landing is absorbed by the trampoline’s elastic surface, making it easier on one’s joints than jumping on the ground.

“Running on a treadmill can be super hard on the joints and knees. Doing jumps on the floor can be hard,” said Ms Nicole Schott, a personal trainer at Future in Cranberry Township, Pennsylvania, who developed trampoline classes. Rebounding “allows for you to do those higher-intensity or even more complex movements without killing your body”.

Embrace your inner kid – or jump with some real ones.

Ms Myriam Gilles, 51, has been rebounding since 2009 at a bouncing studio called The Ness in New York City. The 50-minute classes blend dance choreography, hand weight exercises, sit-ups and planks, all on the trampoline.

“I bounce and SoulCycle,” Ms Gilles said. “They’re just gentler on the body and have a community feeling that I love.”

She said trampolining connects her to distant memories of her childhood in Brooklyn jumping Double Dutch.

“I was one of those black girls who loved to jump-rope. I sometimes think that there’s something about the trampoline that reminds me of that,” she said.

Professor Sarah Shultz, a biomechanist and interim dean for the School of Nursing and Health Studies at Monmouth University in New Jersey, said rebounding on a large outdoor trampoline is an opportunity to connect with her children.

“I have a great time going on it with my kids,” said Prof Shultz, a mother of two. “I can get out of a rough meeting or I’ll get writer’s block trying to write an article and I’ll go, ‘All right, kids. I’ve got five minutes. Let’s make mummy happier.’”

Get started at home

Most experts recommended a trampoline with an 81cm to 121cm jumping surface, which costs about US$50.

Higher-end options can cost 10 times that and may offer a more comfortable springless design, removable legs for easy transport and storage, and adjustable rubber cords, which make the device less noisy and lower-impact as rubber springs are quieter and spongier than their metal counterparts.

If you feel unsteady, experts recommend having a wall within arm’s reach or using walking poles planted on the floor beside the trampoline for balance. To make the workout harder, you can add wrist or ankle weights. Do not get discouraged if it takes you a while to master the basics, though.

“Bounce incorporates balance, cardiovascular, coordination and strength, so there is a bit of a learning curve when you begin,” said Ms Colette Dong, co-founder of The Ness.

Ms Schott and Ms Dong recommended a simple mini-trampoline routine suitable for beginners.

Side-to-side hops with feet together

Keep a slight bend in the knees and your feet together. Hop both feet over to the other side of the trampoline and back. Ms Schott stressed the importance of maintaining a tight core while you do this movement, allowing the motion to come from the feet.

Bounce-down

Start in a squat. Begin to pulse the heels down continuously into the trampoline at a rapid rate while maintaining a squat. Then, using the core, start to lift your knees in towards your centre, lifting your feet off the trampoline while keeping your body low.

“Bounce-down is a simple but effective move that engages the glutes, hamstrings” and inner muscles of your abdomen while getting the heart rate up, Ms Dong said.

High knees

Keeping your knees slightly bent, lift one knee to your chest and alternate as quickly as you can, running in place. To lower the intensity, slow the speed to a march.

Twist

Beginning in a squat, keep your feet slightly wider than your hips and use your obliques to twist the lower body to one side while the shoulders stay square to the front of your space. Allow your opposite arm to swing forward as if you were rolling a bowling ball. Once your feet land facing one side, reverse the action to bring the lower body back to your starting position.

“Twists activate your internal and external obliques, creating opposition through the torso and increasing spinal rotation,” Ms Dong said. NYTIMES