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Is Pre-Workout Bad for You? Here’s What Nutrition Experts Had to Say

Illustration of woman pouring pre-workout in bottle.
Dasha Burobina

If you’re anything like us, you’ve probably turned to the socials for workout inspo over the years. And if, like us, you’ve spent countless hours mindlessly shuffling through #Gymtok and #Fitstagram, then you’ve definitely seen a lot of people using pre-workout before hitting the gym and raving about how it can help your sweat sesh. But is pre-workout bad for you? Well, you’ll be happy to know that the experts say it’s completely safe to use, but with some important caveats to note. We explain below.

Meet the experts

  • Melissa Morris, ISSN-certified sports nutritionist and ACSM-certified exercise physiologist at Expert Insurance Reviews.
  • Blanca Garcia, RDN Nutrition Specialist at HealthCanal.
  • Krutika Nanavati, a New Zealand-based performance nutrition specialist/ sports dietician and Ph.D candidate at Massey University.

What Is Pre-Workout?

No matter how dedicated you are to the fitness, sometimes the notion of lounging on your couch with a bag of Cheetos and bingeing Sex and the City seems more appealing. And even if you do manage to get yourself to the gym, you may find yourself distracted, unfocused and unmotivated. That’s where pre-workout comes in.

“Pre-workouts are a type of sports nutrition supplement with ingredients that are thought to improve exercise performance,” explains Melissa Morris. “There are some ingredients with solid research to show that they either delay fatigue, boost energy levels or enhance recovery.”

Most pre-workouts contain caffeine, beta-alanine, amino acids, B vitamin as well as creatine which aid in keeping you alert and energetic while you workout.

Pre-workout usually comes in the form of shakes, capsules, gummies or liquid supplements. Though most are meant to boost energy levels, you can find formulas that have a lot less caffeine, are stimulant-free or are made with more natural ingredients so you don’t feel jittery after ingesting them.

What Are Some Benefits of Pre-Workout?

In addition to boosting your energy levels and making you feel alert while working out, pre-workout also has the following benefits:

  1. May improve blood flow. Pre-workouts that contain caffeine may increase blood flow because the stimulant works by dilating your blood vessels and allowing your blood to move more. This may in turn help with endurance and muscle strength and can allow you to do more at the gym without feeling like you’re straining.
  2. It can help you stay focused. But only in the short term. Caffeine is renowned for its ability to get you up while working or studying or doing some mundane task. The same applies to exercise. However, you may still be susceptible to that dip in energy afterwards.
  3. May improve recovery time. According to Healthline, your body naturally produces a compound called creatine which is stored in the skeletal muscles and aids in energy production and muscular strength. Taking a pre-workout with this supplement can improve your body’s production of the chemical, which then improves your recovery time as well as muscle mass and strength.

Is Pre-Workout Bad for You?

Just because pre-workouts offer a ton of benefits doesn’t necessarily mean they’re good for you. They’re made up of varying ingredients and there is no sure way of knowing how your body will react.

“There is no definitive answer to this question since everyone's body reacts differently to supplements,” explains Nanavati. “Some people may experience side effects from pre-workout, while others may not. If you are concerned about taking pre-workout, speak to your nutritionist [or primary care physician] to see if it’s right for you.”

What Are Some Potential Side Effects?

“A pre-workout may cause heart palpitations and can affect blood pressure levels if you are on medication,” warns Garcia. “Also, if you are diabetic you may need to actually eat food before working out, exercising with just a pre-workout may not be appropriate and your sugar levels may dip to dangerous levels.”

She adds, “Pre-workouts are harmful or risky for people who experience negative effects from consuming caffeine. They may also be unpleasant side effects if someone doesn’t like the tingling effects of beta-alanine.”

And Nanavati concurs, stating, “Caffeine can cause jitteriness, anxiety, difficulty sleeping and an upset stomach. It is important to limit caffeine intake to 400 mg per day. Pre-workouts can also contain other stimulants such as guarana and yohimbe, which can have similar effects to caffeine.”

Additionally, because of ingredients added for taste, some pre-workouts can be high in calories, which can work against you if you’re trying to lose or manage your weight.

“Another risk of drinking a pre-workout is that it can cause dehydration, which can lead to cramps, headaches and dizziness,” Nanavati tells us. “It is important to drink plenty of fluids before and during exercise.”

The Bottom Line

Whether or not pre-workout is bad for you depends on your individual goals/health. The best way to go about it is to ask your physician—since they have your entire medical history—if you’re a good candidate for taking a pre-workout. Also, Garcia urges you to follow the manufacturer’s recommendation as each pre-workout is unique and can differ in recommended doses.

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