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7 biggest benefits of taking pre-workout before gym sessions

Written by John Davis

Last updated: October 9, 2022

Pre-workouts are multi-ingredient supplements that are formulated to boost exercise performance.

A pre-workout supplement achieves its goals by combining the effects of central nervous system stimulants like caffeine, compounds that boost anaerobic power generation capabilities like beta-alanine, L-carnitine, and creatine, and raw building blocks for muscle, like branched-chain amino acids.

The right pre-workout can elevate your workout performance to new heights. Read on for the biggest benefits of pre-workout supplements and the key ingredients that make these benefits possible.

Pre-workout benefits

1. Pre-workouts combine the effects of multiple individual ergogenic compounds

These compounds help boost protein synthesis, elicit maximum muscle strength, and give you a boost in energy levels, all of which combine for a more effective workout.

2. Pre-workouts with caffeine can improve endurance, coordination, strength, and stop-and-go sport performance

According to a review by the International Society of Sports Nutrition, caffeine is a highly effective performance enhancer (1).

Caffeine works for many different types of exercise, including endurance (running cycling, rowing) to intense coordination and starting and stopping (pickup basketball, ultimate Frisbee, HIIT training) and maximal strength (Olympic and powerlifting).

3. Pre-workouts with L-carnitine increases anaerobic power and strength

Research done at the University of Connecticut shows that taking L-Carnitine after a strength workout increased the activity of the androgen receptor response (2), meaning that your muscles get more attuned to the muscle-building effects of androgen hormones like testosterone.

4. Pre-workouts that include beta-Alanine can boost anaerobic power as well

Beta-alanine builds up your muscular content of carnosine, which helps increase your tolerance for the buildup of acidity in your muscles.

According research out of the University of Sao Paulo in Brazil, beta-alanine improves performance in short, high-intensity exercise and delaying the “burn” during high-intensity exercise that causes fatigue (3).

5. A pre-workout with creatine can increase muscle mass and strength by up to 25-30%

Research shows that when taken consistently, creatine can increase muscular creatine content by over 20%, and muscular cross-sectional area and raw strength by 25-30% (4).

6. More advanced pre-workout ingredients like yohimbe could help cut body fat

According to a study published in 2006 (5), yohimbe supplementation in athletes could lead to a drop in body fat percentage over a period as short as 21 days. Pre-workouts with yohimbe could be a useful way to drop body fat, even while continuing an intense training program.

7. BCAAs in a pre-workout supplement can help prevent soreness

BCAAs reduce the damage induced by intense workouts, according to research published in the journal Medicine and Science in Sport and Exercise (6).

This means that branched chain amino acids are particularly well-suited for workouts with a lot of eccentric-dominated exercises like squats, RDLs, and lunges.

Pre-workout side effects

Pre-workout supplements with high doses of caffeine can cause nausea, jitters, and sleeplessness. When taken in too high of a dose, caffeine can even cause heart arrhythmias, seizures, and other serious medical problems.

Women are more likely to experience sleeplessness from pre-workout supplements. Because estrogen affects how quickly caffeine is metabolized from the body, women (especially those taking hormonal contraceptives) can have hugely different responses to how long the anti-fatiguing effects of caffeine in pre-workout lasts.

Some women might find that taking pre-workout even in the morning can negatively affect their sleep the next night: if this is the case, try a stimulant-free pre-workout instead.

Pre-workouts with synephrine might interact negatively with caffeine. A few pre-workout supplements contain bitter orange or its active ingredient, synephrine.  This ingredient has caused some doctors to issue warnings that it has a side effect and biological profile similar to that of the banned stimulant ephedra.

If you’re concerned about the potential cardiovascular side effects of synephrine, avoid supplements that contain it—especially when they also contain caffeine (7).

Beta-alanine in pre-workouts can cause mild tingling or prickling sensations. These sensations are called ‘parathesia’, and are a mild and common sensation in response to beta alanine dosing.

This sensation is the result of peak levels of beta-alanine in the blood, so all you need to do to avoid this in the future is split up your pre-workout supplement into smaller doses taken at thirty or sixty minute intervals.

Pre-workout dosage

Pre-workout dosing depends on the exact formulation, but here are some key guidelines:

Caffeine dosage should be 3 to 6 mg per kilogram of body weight—so a 170 pound man (77 kg) would consume 230 mg of caffeine to get a dose of 3 mg/kg. Doses >6 mg/kg don’t appear to be any more effective and they have a higher incidence of negative side effects.

Creatine dosage can be up to 25 g. If your pre-workout supplement doesn’t have this much, add a separate separate creatine supplement that you take during the day.

Beta-alanine dosage can be up to 1000-1500 mg. Ideally, your beta-alanine dosage would be split up into a few different doses taken at 30-60 minute intervals.

Pre-workout benefits FAQ

Q: What are some good natural pre-workouts?

A: If you want the most effective natural pre-workouts, look for green tea extract, coffee, yohimbe, and guarana to boost workout performance, B-complex vitamins for more energy, carnitine and beta-alanine for better anaerobic performance, and compounds like BCAAs and glutamine to boost recovery and reduce soreness.

Q: Is pre-workout safe?

A: Most pre-workout ingredients are safe, but the biggest risk comes from stimulants, which can range from garden-variety things like caffeine to more potent and also potentially more dangerous compounds like synephrine or bitter orange peel.

In rare cases these stimulants can cause heart rhythm problems, especially when used in combination and at high doses. 

Q: Are pre-workout supplements necessary?

A: If you just want to get a solid effort in at the gym, and aren’t looking to smash any records or push yourself up to your body’s physiological limit, a pre-workout is not going to be necessary to achieve your workout goals.

If you are looking to max out a lift, or push yourself harder than ever in a HIIT session, a pre-workout supplement might be just what you need.

Pre-workouts can also be useful when you are not feeling up for high-level performance, but still need to work out.

Prime example? Early-morning gym sessions. If you are sleep-deprived but need to kick your body into high gear, a pre-workout supplement is one surefire way to do it.

Q: Why does pre-workout make you tingle?

A: Tingling after taking a pre-workout supplement means one of two things: either the pre-workout supplement that you are taking has a lot of beta-alanine, or a lot of niacin (also known as vitamin B3).

Both of these ingredients cause flushing and tingling at high doses, and while this side effect is unpleasant, it isn’t harmful.

Related: Our best pre-workout picks


Need to amp up your workout performance? A pre-workout is the way to go.

By boosting anaerobic power output, increasing the activity of your central nervous system, and giving your muscles the raw fuel they need for performance, pre-workouts help you take your performance in the gym to the next level.

Getting the dosage right for key ingredients like caffeine and beta-alanine can help you dial in maximum performance with minimal side effects.


John Davis

John Davis is a Minneapolis-based health and fitness writer with over 7 years of experience researching the science of high performance athletics, long-term health, nutrition, and wellness. As a trained scientist, he digs deep into the medical, nutritional, and epidemiological literature to uncover the keys to healthy living through better nutrition.