SUNDAY, April 21, 2019 (HealthDay News) -- High-intensity interval training may boost your fitness at a cost -- perhaps increasing your risk for injuries.
This popular type of training combines aerobics, weight lifting and calisthenics at maximum effort, followed by recovery periods.
"These workouts are marketed as 'one size fits all.' However, many athletes, especially amateurs, do not have the flexibility, mobility, core strength and muscles to perform these exercises," said study author Dr. Joseph Ippolito. He's an orthopedist at Rutgers New Jersey Medical School.
Researchers analyzed 2007-2016 U.S. government data and identified 3.9 million injuries caused by exercise equipment (such as barbells and kettle bells) or calisthenics (such as pushups and lunges) that are common in interval training.
Most of those injuries involved knees, ankles and shoulders. White males ages 20 to 39 had the highest injury rate.
There were an average of nearly 51,000 injuries a year, and the number rose alongside rising interest in interval workouts.
Significant increases in nerve damage, internal organ injuries, concussions, puncture wounds, dislocations and strains and sprains were seen during the study period, according to the study.
Doing interval workouts without supervision raises risk for injury from poor form and muscle overuse, according to Ippolito.
"There is strong evidence that these types of injuries -- specifically from repetitive overload at the knee -- can lead to osteoarthritis," Ippolito said in a university news release.
The study results are in the Journal of Sports Medicine and Physical Fitness.
If you're new to interval training, talk to your doctor first, the researchers advised.
"We certainly do not want to discourage people from this type of exercise because of its numerous health benefits, but recommend that they understand the pre-existing conditions and physical weaknesses that may predispose them to injury," said study co-author Nicole Rynecki, a medical school student.
So what are the benefits? Interval training can improve heart-lung fitness, boost energy, build lean muscle mass, and burn fat, according to the study.
The U.S. Centers for Disease Control and Prevention has more on physical activity.