Popular Gym Supplements Linked to Dangerous Sleep Loss in Young People

Widely used pre-workout supplements may be linked to severely reduced sleep in teens and young adults.

A scoop of pre-workout can feel like a shortcut to motivation, especially for teens and young adults juggling school, work, and training. But new findings from the Canadian Study of Adolescent Behaviors suggest that the energy boost may come with a tradeoff: much shorter sleep.

In a sample of participants ages 16 to 30, people who said they had used pre-workout supplements, such as Bang!, Jack3D, and C4, in the past year were more than twice as likely to report sleeping five hours or less per night than those who did not use them. That is far below the roughly eight hours of sleep generally recommended for this age range, and it lands in a zone many sleep researchers consider risky when it becomes routine.

High Stimulant Content Raises Concerns

“Pre-workout supplements, which often contain high levels of caffeine and stimulant-like ingredients, have become increasingly popular among teenagers and young adults seeking to improve exercise performance and boost energy,” says lead author Kyle T. Ganson, assistant professor at the Factor-Inwentash Faculty of Social Work at the University of Toronto. “However, the study’s findings point to potential risks to the well-being of young people who use these supplements.”

Current sleep guidelines advise that adolescents get 8 to 10 hours of sleep per night and that young adults aim for 7 to 9 hours. Despite these recommendations, many young people in Canada already do not get enough rest. The researchers caution that the stimulating ingredients found in many pre-workout formulas could be worsening sleep problems during an important period of growth and development.

Caffeine Levels Far Exceed Common Beverages

“These products commonly contain large doses of caffeine, anywhere between 90 to over 350 mg of caffeine, more than a can of Coke, which has roughly 35 mg, and a cup of coffee with about 100 mg,” said Ganson. “Our results suggest that pre-workout use may contribute to inadequate sleep, which is critical for healthy development, mental well-being, and academic functioning.”

To put that in perspective, 90 to 350 milligrams of caffeine is roughly equal to about 0.0014 to 0.0054 ounces. At the higher end, a single serving can contain several times the caffeine found in a typical soda and significantly more than a standard cup of coffee.

The authors say health and mental health professionals, including pediatricians, family doctors, and social workers, should routinely ask young patients about pre-workout supplement use. They also recommend practical harm reduction steps, such as avoiding these products 12 to 14 hours before bedtime. In addition, the findings add to calls for stricter oversight of dietary supplements in Canada.

“Young people often view pre-workout supplements as harmless fitness products,” Ganson noted. “But these findings underscore the importance of educating them and their families about how these supplements can disrupt sleep and potentially affect overall health.”

Reference: “Use of pre-workout dietary supplements is associated with lower sleep duration among adolescents and young adults” by Kyle T. Ganson, Alexander Testa and Jason M. Nagata, 30 November 2025, Sleep Epidemiology.
DOI: 10.1016/j.sleepe.2025.100124

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