Pre-workout supplements have become extremely popular among teenagers and young adults who want fast energy and stronger workouts. Yet, many of these same users report feeling unusually tired or mentally drained the next day. Although these products promise motivation, focus, and performance gains, they may also undermine one of the most essential pillars of health: sleep. Because sleep directly supports mood, learning, immunity, and muscle repair, any disruption can harm both daily functioning and long-term well-being.

Most pre-workout formulas rely on a predictable list of stimulating ingredients. Common components include caffeine, creatine, amino acids, nitrates, beta-alanine, and artificial sweeteners. Caffeine is the most powerful compound, and it is known to shorten sleep duration while delaying normal melatonin release. Since many young people train after evening classes, late work shifts, or social commitments, their supplement use often occurs dangerously close to bedtime.

Even though pre-workout consumption has increased, clear guidance about timing, safety, and sleep management remains limited. Moreover, scientific understanding is still incomplete, especially regarding how different doses, ingredient combinations, and consumption patterns affect real-world sleep quality. Because of this gap, recent research has tried to measure how pre-workout habits connect to sleep routines in everyday life among adolescents and young adults.

Measuring Supplement Habits Against Sleep Patterns

To explore these patterns, investigators analyzed data from Wave 2 of the Canadian Study of Adolescent Health Behaviors. This survey targeted people aged 16 to 30 across Canada and was conducted entirely online using the Qualtrics platform. Several security measures—such as reCAPTCHA, attention checks, and hidden honeypot items—were implemented to protect against bots and ensure high data quality. Ethical approval was granted by the University of Toronto Health Sciences Research Ethics Board, and all participants provided written informed consent before joining the study.

Pre-workout use was measured by asking respondents whether they had consumed any pre-workout supplements within the past twelve months. Answers were recorded as either “any use” or “no use.” These products were categorized together with other appearance- and performance-enhancing supplements. Sleep duration was self-reported as the average number of hours slept each night during the previous two weeks. Responses were grouped into five categories: five hours or less, six hours, seven hours, eight hours, and nine hours or more. Eight hours was selected as the reference group because it aligns with widely accepted sleep guidelines.

Several important covariates were included. These variables covered age, gender identity, race or ethnicity, sexual orientation, and educational background. Mental health factors such as depressive symptoms and anxiety symptoms were assessed using the Patient Health Questionnaire 9-Item (PHQ-9) and the Generalized Anxiety Disorder 7-Item (GAD-7). Additionally, weight-training behavior was measured by asking whether participants had engaged in any strength training during the prior thirty days. These factors were necessary because mental health challenges, academic pressures, and exercise habits can all shape sleep patterns independently of supplement use.

Multinomial logistic regression was used to estimate the associations between pre-workout use and sleep duration. This method allowed researchers to compare each sleep category with the eight-hour reference group. Multicollinearity was assessed with Variance Inflation Factors (VIFs). Although PHQ-9 and GAD-7 scores were correlated, all other VIFs remained below 2, indicating no concerning overlap among predictors. Possible gender-based differences were tested but were not statistically significant. Model fit was evaluated with chi-square statistics and pseudo-R² calculations. All analyses were completed using Stata 17.0.

One in Five Young People Used Pre-Workouts This Year

The final sample represented a diverse group of adolescents and young adults. The average age was 23.4 years with a standard deviation of 3.8 years. In terms of gender identity, 57.4% identified as girls or young women, 33.8% identified as boys or young men, and 8.8% identified as transgender or gender-expansive. Participants reflected Canada’s broad population: 62.2% identified as White, 17.1% as Asian, 3.5% as Black, 11.0% as multiracial, and 6.2% as another identity. Around 55.1% identified as heterosexual.

Approximately one in five respondents—22.2%—reported using pre-workout supplements within the past twelve months. This level of use highlights how deeply these products have entered youth fitness culture. Many users described taking pre-workouts before weight training, sports practices, or recreational workouts.

Sleep patterns varied widely. The most common sleep duration was around seven hours per night, reported by 34.9% of participants. Another 25% slept approximately six hours per night, while 20.4% slept a full eight hours. About 9% reported sleeping nine hours or more. However, 10.6% reported sleeping five hours or less, revealing a notable minority experiencing extremely short sleep.

The statistical model performed strongly, showing meaningful and consistent patterns. After controlling for demographic factors, mental health symptoms, and recent weight-training habits, pre-workout use remained strongly associated with very short sleep. Compared with those sleeping eight hours, users were more than twice as likely to report sleeping five hours or less. However, the study did not find meaningful associations between pre-workout use and other sleep categories such as six, seven, or nine-plus hours of sleep.

These findings align with existing scientific knowledge about caffeine. Since most pre-workout formulas contain high levels of caffeine—sometimes equal to two or three cups of coffee—late-day use can delay sleep onset and reduce total sleep duration. Because many adolescents and young adults complete workouts after classes, social events, or part-time jobs, supplement intake often occurs close to bedtime, increasing the risk of disrupted sleep.

Although the models accounted for mental health symptoms and weight training, the cross-sectional design prevents researchers from drawing direct causal conclusions. It remains possible that individuals who routinely experience short sleep may turn to pre-workouts as a temporary energy boost. Nonetheless, the magnitude of the association suggests that even occasional pre-workout use can push sensitive users into very short sleep patterns that fall far below recommended guidelines.

Furthermore, the distribution of sleep durations shows that fewer than one in three participants reached the recommended eight hours or more. This pattern indicates that short sleep is a widespread challenge among today’s youth, even among those who do not use supplements. Consequently, the added risks from pre-workouts may place additional strain on an already sleep-deprived population.

Taken together, the adjusted estimates show that pre-workout use is specifically linked to the shortest sleep category, rather than the entire sleep duration spectrum. This targeted effect highlights a meaningful connection that deserves attention from health educators, policymakers, and clinicians.

Guidance Needed on Timing, Dose, and Sleep Protection

This study sheds important light on how pre-workout supplements may influence sleep among young people. Adolescents and young adults who use these products face significantly higher odds of experiencing extremely short sleep, even after accounting for key demographic and behavioral factors. Because many workouts occur during afternoon or evening hours, the timing of stimulant intake becomes central to this problem. Caffeine and related compounds consumed near bedtime can undermine recovery, learning, emotional stability, and athletic development.

Therefore, practical guidance is urgently needed. Young people should be encouraged to avoid pre-workout supplements for several hours before bedtime. Labels should be read carefully because caffeine content varies widely among products. Because some brands include ingredients equivalent to several cups of coffee, users may unknowingly consume excessive stimulant doses. Sleep hygiene practices, such as maintaining a consistent bedtime, reducing evening screen time, and creating a calm sleep environment, should also be emphasized.

Future research should examine dose, timing, and ingredient combinations more closely. Studies using prospective designs would help clarify whether pre-workouts cause short sleep or whether short sleepers seek extra stimulation. Additionally, ingredient-specific analyses could help identify which compounds contribute most strongly to sleep disruption. This evidence would support better education, stronger policy decisions, and safer clinical recommendations.

As pre-workout supplements continue growing in popularity, understanding their real-world effects on sleep will be essential. Balanced guidance that protects both health and athletic goals will help young people use these products more responsibly.