A new study from the Research Institute at the Nationwide Children's Hospital in Columbus, Ohio, has found that as weight training has grown in popularity, so too has the number of weight training-related injuries.

The study found that more than 970,000 weight training-related injuries were treated in US hospital emergency departments between 1990 and 2007, increasing nearly 50 per cent during the 18-year study period.

Males (82 per cent) and youths aged 13 to 24 years (47 per cent) sustained the largest proportion of weight training-related injuries. The majority of injuries occurred during the use of free weights (90 per cent), and the most common injury was caused by weights dropping on a person (65 per cent).

Injuries to the upper (25 per cent) and lower trunk (20 per cent) were the most common, followed by injuries to the hand (19 per cent). The most frequent injury diagnoses were sprains and strains (46 per cent) followed by soft tissue injuries (18 per cent).

While youths (ages 13-24) had the highest number of injuries, the largest increase in the incidence of injuries occurred among those aged 45 years and older. People aged 55 and older were more likely than their younger counterparts to be injured while using weight-training machines, and to sustain injuries from overexertion and lifting or pulling.

However, youths 12 years and younger were more likely to be injured while using free weights. This age group had a higher proportion of lacerations and fractures, and were more likely to sustain injuries as a result of having a weight drop or fall on them than those aged 13 years and older.

Study author Dawn Comstock, Ph.D, principal investigator in the Center for Injury Research and Policy at the Nationwide Children’s Hospital, said: “Getting proper instruction on how to use weight lifting equipment and the proper technique for lifts, as well as providing trained supervision for youths engaging in weight training, will reduce the risk of injury.”

The study also found that while males had the highest number of injuries, there was a larger increase in the incidence of injury among female participants.

“Weight training may still be a male dominated activity,” said Dr. Comstock. “However, the increase in incidence among female participants is likely the result of more women weight training as it becomes a more accepted fitness activity for women.”