HIIT workouts found to increase injury risk

People who engage in high-intensity interval training are at greater risk for injury, especially in the knees and shoulders, a Rutgers study has found.

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High intensity interval training (HIIT) is seen as a key part of a training schedule, helping athletes reach a higher level of fitness quicker and more efficiently than just clocking up the miles. But now new research has found that this type of training can increase risk of injury.


HIIT workouts exercise the cardiovascular system, which will then improve the athlete’s aerobic capacity leading them to exercise for longer and/or more intense levels.

However, scientists from Rutgers University have found that although this type of training is effective in improving cardiorespiratory fitness, boosting energy and promoting lean muscle mass and fat loss, it also increases injury risk.

“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 Joseph Ippolito, a physician in the department of orthopaedics at Rutgers New Jersey Medical School.

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The scientists analysed records in the National Electronic Injury Surveillance System from 2007 through 2016, and found 3,988,902 injuries resulting from exercise equipment, such as barbells, kettle bells and boxes, or calisthenics, such as burpees, push-ups and lunges, that are common to these programs. Most injuries involved knees, ankles and shoulders. White males aged 20 to 39 were most injured.

Athletes who perform these workouts without supervision are at increased risk for injury from poor form and muscle overuse, say the researchers.

“There is strong evidence that these types of injuries, specifically from repetitive overload at the knee, can lead to osteoarthritis,” said Ippolito.

“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 co-author Nicole D. Rynecki, a student at the medical school.

Since knee and ankle sprains and strains were the most common injuries from high-intensity interval workouts, people should do neuromuscular training — especially those that focus on strength, jumping and balance — and pre-strengthening programs to improve flexibility before starting high-intensity interval exercises, Rynecki said.

“Exercises such as stretches that can increase range of motion and strengthen rotator cuff muscles are important, especially for older people and those who are predisposed to rotator cuff tears,” she said.

220’s strength and conditioning coach Nick Beer says, “HIIT has become increasingly popular with athletes and the time pushed individual. The physiological benefits are great and the calories burnt in a short amount of time make this method highly desirable. However, as the article states, there is a detrimental side to this in vogue fitness trend.

“Classes can be up to 40 people and led by one instructor,” continues Beer. “There’s no way that they can coach, demonstrate and correct each persons technique effectively to carry out each exercise. There needs to be more of these articles published to increase awareness of the risk of injury while engaging in HIIT training. This could give rise to more technique specific-led classes that will graduate you into HIIT training and may put a stronger emphasis on the development of more competent and skilful instructors. Or gyms could have smaller class numbers with more instructors involved. However, this could require gyms to empty their pockets a little more to ensure the wellbeing of their clients. We can wait and see where the importance lies!


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“Triathletes can benefit from HIIT training,” adds Beer, a former elite triathlete, “as it can improve their VO2 max and have a positive impact on their performance. This article should reiterate the importance of good technique when taking part in HIIT training. It is easy to blast out a HIIT session on the bike, for example, but are you able to hold a good position? Keep your upper body relaxed? Stay still on the saddle? And manage to hit target watts? The importance of perfecting your technique in order to carry out these sessions will ultimately improve performance and increase longevity in the sport.”

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