Popular pre-workout supplements linked to dangerous sleep loss
That pre-workout boost might come with a surprising downside: dramatically less sleep for young users.
- Date:
- March 9, 2026
- Source:
- University of Toronto
- Summary:
- Pre-workout supplements promising extra energy for workouts may come with a hidden cost: severely reduced sleep. A study of people aged 16–30 found users were more than twice as likely to sleep five hours or less per night. Many of these products pack huge doses of caffeine and stimulants that can linger for hours. Researchers say the findings raise concerns about the impact on young people’s health and development.
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A new analysis from the Canadian Study of Adolescent Behaviors suggests that teenagers and young adults who take pre-workout dietary supplements, including products like Bang!, Jack3D, and C4, are far more likely to experience extremely short sleep durations.
Researchers examined data from more than participants between the ages of 16 and 30. The results showed that people who reported using pre-workout supplements within the past year were more than twice as likely to say they sleep five hours or less per night compared with those who did not use these supplements. For this age group, experts generally recommend about eight hours of sleep each night.
"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."
High Caffeine Levels May Worsen Sleep Problems
Health guidelines advise that adolescents should sleep 8-10 hours per night, while young adults should aim for 7-9 hours. Despite these recommendations, many young Canadians do not get enough sleep. According to the researchers, stimulant ingredients commonly found in pre-workout products may be making this problem worse during an important stage of physical and mental development.
"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."
Researchers Call for Education and Regulation
The research team says health and mental health professionals, including pediatricians, family physicians, and social workers, should talk with young people about their use of pre-workout supplements. They also recommend practical harm reduction steps, such as avoiding these supplements 12 to 14 hours before going to bed.
The findings also strengthen calls for tighter 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."
Story Source:
Materials provided by University of Toronto. Note: Content may be edited for style and length.
Journal Reference:
- Kyle T. Ganson, Alexander Testa, Jason M. Nagata. Use of pre-workout dietary supplements is associated with lower sleep duration among adolescents and young adults. Sleep Epidemiology, 2025; 5: 100124 DOI: 10.1016/j.sleepe.2025.100124
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