Walk into any powerlifting gym and you'll see the same pre-session options: a tub of pre-workout powder, a can of energy drink, or a coffee. All three are ways to get caffeine. This page looks at what the research says about caffeine and strength, what else comes along with each option, and how to compare labels so you know what you're actually taking.
This is general information about published research, not medical or training advice.
What the Research Says About Caffeine and Strength
The main reference document is the International Society of Sports Nutrition (ISSN) position stand on caffeine and exercise performance (Guest et al., Journal of the International Society of Sports Nutrition, 2021). Its summary points include:
- Small to moderate benefits of caffeine have been reported for muscular endurance, movement velocity and muscular strength, as well as sprinting, jumping and throwing.
- Caffeine has consistently been shown to improve exercise performance in studies that used 3 to 6 mg per kilogram of body mass. The minimal effective dose remains unclear and may be as low as 2 mg/kg.
- Very high doses (around 9 mg/kg) are associated with a high incidence of side effects and do not appear to be needed for a performance effect.
- The most commonly used timing in studies is 60 minutes before exercise, and the best timing may depend on the caffeine source.
- Responses differ between individuals, linked in part to genetics and habitual caffeine intake, and side effects such as disrupted sleep or anxiety vary from person to person.
For strength specifically, a 2018 meta-analysis by Grgic and colleagues in the same journal (PubMed) pooled 10 studies on strength and 10 on power. It reported a small effect of caffeine on strength (standardized mean difference 0.20) and on power (0.17), with a significant effect on maximal upper-body strength. The authors called for better control of blinding and more research in women.
These are averages across study groups under lab conditions. They don't predict what any one lifter will see.
Energy Drinks and Pre-Workouts Are in the Research Too
It's easy to frame this as coffee versus everything else. The research doesn't. The ISSN position stand states that energy drinks and pre-workout supplements containing caffeine have been demonstrated to enhance both anaerobic and aerobic performance. So the real differences between options are what else is in the product and how clearly the label states the caffeine.
What to Check on a Pre-Workout or Energy Drink Label
- Total caffeine. The FDA notes that most U.S. energy drinks list the total amount of caffeine from all sources on the label, and that energy drinks generally have 54 to 328mg of caffeine per 16 fl oz (FDA). Find the number before you drink it.
- Other stimulants and actives. Pre-workout powders often contain ingredients beyond caffeine. Some labels list a "proprietary blend" by total weight without the amount of each ingredient. Read the supplement facts panel so you know what you're comparing.
- Added sugar. The FDA's Daily Value for added sugars is 50 grams a day on a 2,000 calorie diet (FDA). Some lifters want carbohydrate before training and some don't. Either way, the Added Sugars line tells you what's there.
- Sweeteners and colors. These appear in the ingredient list. Whether you want them is your call.
Count Your Whole Day
FDA says up to 400mg a day is an amount not generally associated with negative effects for most healthy adults (FDA). The FDA also notes that people vary widely in how sensitive they are to caffeine, and that certain conditions and some medications can make people more sensitive. Morning coffee, a pre-workout scoop and an afternoon can all add up. If you have a heart condition, are pregnant or nursing, or take medication, talk to your doctor before using caffeine around training.
Frequently Asked Questions
Does caffeine help with strength training?
The ISSN position stand lists small to moderate benefits for muscular strength and endurance, and a 2018 meta-analysis reported a small effect on strength and power. Individual responses vary.
What caffeine doses have studies used?
According to the ISSN, studies have consistently shown performance effects at 3 to 6 mg per kilogram of body mass, and very high doses around 9 mg/kg were associated with frequent side effects. That's a description of the research, not a recommendation for you. Ask your doctor what makes sense for you.
Do energy drinks and pre-workouts work as well as coffee?
The ISSN states that energy drinks and pre-workout supplements containing caffeine have been shown to enhance both anaerobic and aerobic performance. The differences are the other ingredients and how clearly the caffeine is labeled.
How much caffeine does FDA say is OK in a day?
FDA says up to 400mg a day is an amount not generally associated with negative effects for most healthy adults. Sensitivity varies, and some conditions and medications increase it.
Keep Reading
- Hyrox Caffeine Strategy: What the Research Says
- Cold Brew vs Energy Drinks
- How Much Caffeine Is in Cold Brew Coffee?
- How to Reset Your Caffeine Tolerance
About Bare Brew
Bare Brew is our own product. No sugar. No dairy. Bare ingredients, a special blend of coffee and water. Each 12 fl oz can has 320mg of caffeine, 20 calories, 0g sugar and 5g total carbohydrate, made with filtered water and Honduran Arabica. See the label and current prices.
Sources:
- Guest NS, et al. "International society of sports nutrition position stand: caffeine and exercise performance." J Int Soc Sports Nutr. 2021;18:1.
- Grgic J, et al. "Effects of caffeine intake on muscle strength and power: a systematic review and meta-analysis." J Int Soc Sports Nutr. 2018;15:11.
- U.S. Food and Drug Administration. "Spilling the Beans: How Much Caffeine Is Too Much?"
- U.S. Food and Drug Administration. "Added Sugars on the Nutrition Facts Label."
This article is general information, not medical advice. Bare Brew is a coffee drink, not a treatment for any condition. Each 12 fl oz can has 320mg of caffeine. It's not recommended for children, people who are pregnant or nursing, or anyone sensitive to caffeine. If you take medication or have a health condition, talk to your doctor about caffeine.
