VITAMINS & SUPPLEMENTS · PREGNANCY
Pre-Workout for Teens, in Pregnancy and With Heart Conditions: Who Should Avoid It
What pediatric, pregnancy and heart-health sources say about caffeine and stimulant products, and why teens, pregnant people and people with heart conditions should ask a clinician before pre-workout.
Content last updated . This page has not been medically reviewed.
Back to Pre-Workout Supplements: What They Contain, Ingredient by IngredientWhat official sources say, by group
Children and teens, US
FDA reports that medical experts advise against energy drinks for children and teens because of sugar and caffeine. [2] Too much caffeine in this age group can cause increased heart rate, palpitations, high blood pressure and anxiety. [2]
Children and teens, US pediatricians
The American Academy of Pediatrics clinical report says caffeine and other stimulants in energy drinks have no place in the diet of children and adolescents. [3]
Children and teens, EU
A safety level of 3 mg per kg of body weight a day is proposed for habitual caffeine intake. [4]
Children and teens, Canada
2.5 mg per kg of body weight, for up to age 18. [5]
Pregnancy, UK
No more than 200 mg of caffeine a day; too much has been linked to a higher chance of miscarriage and stillbirth. [6]
Pregnancy, EU
Up to 200 mg a day from all sources does not raise safety concerns for the foetus. [4]
Pregnancy or breastfeeding, Canada
300 mg a day. [5]
Heart conditions, UK
Seeing a GP is advised for recurrent palpitations, or if you have a heart condition. [7]
These sources disagree on numbers, which is why no single figure is universal. They also describe energy drinks and caffeine, not pre-workout powders. The AAP report is about drinks. Pre-workout powders and capsules are not covered by that report as far as we read. Caffeine from all sources adds up. FDA lists energy bars, supplements and some medicines as sources. [2]
Teens and pre-workout
Besides caffeine, other ingredients matter. The ISSN creatine position says label warnings against use under 18 are probably a legal precaution, and that creatine use in young athletes is acceptable only with proper precautions and supervision. [8] That statement is about creatine alone, not a multi-ingredient blend. Where a teen is training, a pediatrician or sports doctor is the right person to ask. See children and teens: natural remedy safety.Heart conditions
FDA says certain conditions make people more sensitive to caffeine. [2] The NHS says palpitations are usually harmless but lists caffeine as a trigger and advises a GP visit if you have a heart condition. [7] FDA warns that DMAA can raise blood pressure and cause heart problems such as arrhythmias and heart attack. [10] A review of case reports of synephrine-containing pre-workouts found chest pain, palpitations and fainting, though caffeine could not be ruled out as a cause. [11] Case reports cannot show how common these events are. If you have a heart condition, arrhythmia, high blood pressure or take heart medicines, ask your cardiologist or pharmacist before any stimulant product. See side effects.Frequently asked questions
Is pre-workout safe for teenagers?
We found no source that tested pre-workout blends in teens. The American Academy of Pediatrics says caffeine and stimulants in energy drinks have no place in the diet of children and adolescents. [3]
Can I use pre-workout while pregnant?
Official caffeine limits exist (200 mg a day from the NHS and EFSA, 300 mg from Health Canada), but no source we read tested pre-workout blends in pregnancy. [6] [4] [5] Ask your midwife or doctor.
Can pre-workout cause heart problems?
Case reports describe chest pain, palpitations and fainting with some stimulant products, but they cannot show how common this is. [11]
Is caffeine-free pre-workout safe in pregnancy?
We found no pregnancy safety data for the usual caffeine-free ingredients in the sources we read. [9]
Who should I ask?
A doctor, midwife, cardiologist or pharmacist who knows your history. Bring the product label.
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
Pregnancy and breastfeeding
Others who should ask first
- People who take medicines: see medication interactions.
- Older adults: EFSA noted no studies of middle-aged or elderly people doing intense exercise after caffeine. [4]
- Kidney or liver disease; before surgery: talk to your care team. NCCIH says supplements may increase bleeding risk or affect anesthesia. [9]
- Anyone buying a product: see quality testing and certifications.
References
- Jagim et al., Common Ingredient Profiles of Multi-Ingredient Pre-Workout Supplements, Nutrients 2019. Read 2026-10-23.
- FDA: Spilling the Beans, How Much Caffeine Is Too Much? (content current 08/28/2024). Read 2026-10-23.
- AAP clinical report: Sports drinks and energy drinks for children and adolescents, Pediatrics 2011. Read 2026-10-23.
- EFSA: Caffeine, summary of the 2015 Scientific Opinion on the safety of caffeine. Read 2026-10-23.
- Health Canada: Caffeine in foods (maximum daily amounts table; year not shown in the text we read). Read 2026-10-23.
- NHS: Foods to avoid in pregnancy, caffeine section (page reviewed June 2026). Read 2026-10-23.
- NHS: Heart palpitations (page reviewed March 2026). Read 2026-10-23.
- ISSN position stand: safety and efficacy of creatine supplementation (accepted 2017). Read 2026-10-23.
- NCCIH: Using Dietary Supplements Wisely. Read 2026-10-23.
- FDA: DMAA in Products Marketed as Dietary Supplements (August 2018 text; content current 02/22/2023). Read 2026-10-23.
- Review of Case Reports on Adverse Events Related to Pre-workout Supplements Containing Synephrine, Cardiovascular Toxicology 2023. Read 2026-10-23.