I love caffeine. There! I admit my addiction and fascination with this white xanthine alkaloid. If caffeine and I were a love affair, it’d be like Antony and Cleopatra, Lancelot and Guinevere or Romeo and Juliet. Wait a minute. Doesn’t someone die in these little kiss-fests? OK, not exactly the best analogy. But you get my drift. Nonetheless, if I don’t get my caffeine-filled java fix first thing in the morning, it does feel like death. But once I down the first mug, the birds sing, the clouds part, the sun shines and a Victoria’s Secret model appears at my doorstep asking to have suntan lotion rubbed on her back. OK, not really. But it would be nice if that’s what actually happens. So what does caffeine do? What’s the evidence for its use in athletics?
Suffice it to say that the evidence supporting the performance-enhancing effects of caffeine is stacked higher than a Hollywood starlet after her fifth augmentation. According to a position paper by the International Society of Sports Nutrition, there is a plethora of evidence that shows that the acute consumption of caffeine can help both strength-power and endurance activities.1 And for you science geeks, the proof is in the hundreds of studies published on caffeine. However, there’s no need to review all of these studies. Here are some key ones to shed some light on this amazing supplement.
Caffeine and Exercise
Thirteen resistance-trained men ingested a caffeinated (179 mg) energy drink or placebo solution 60 minutes before completing a bout of the following exercises: bench press, deadlift, prone row and back squat to failure at an intensity of 60 percent one-repetition maximum (1RM). Subjects who consumed the caffeinated beverage performed more repetitions to failure in all exercises. The RPE or ratings of perceived exertion was higher in the placebo condition.2 Another study had 15 women consume caffeine (6 mg/kg) or placebo (PL) seven days apart. That dose is roughly 327 milligrams of caffeine for a 120-pound woman. Sixty minutes following supplementation, participants performed a 1RM barbell bench press test and repetitions to failure at 60 percent of 1RM. Researchers discovered that 1RM strength was greater during the caffeine condition in these resistance-trained women.3
And get this— a chewing gum that’s caffeinated! Move over, Wrigley. In this gum study, eight male cyclists participated in five separate laboratory sessions. In their first visit, their maximal oxygen consumption (VO2 max) was determined. During the next four visits, three pieces of chewing gum were administered at three timed points (120 minutes pre-cycling, 60 minutes pre-cycling and 5 minutes pre-cycling). The dose of caffeine given was 300 milligrams. Researchers discovered that caffeine administered in a chewing gum enhanced cycling performance when administered immediately prior to cycling, but not when administered one or two hours before cycling.4
Clearly, caffeine can help both endurance and strength-related exercises. But it does so much more than that. Another study determined the effects of caffeine on repeated sprint ability, reactive agility time, sleep and next-day exercise performance. Did you get all that? Ten male athletes consumed a placebo or caffeine (6 mg per kg of bodyweight) one hour prior to exercise. Significant improvements were shown after caffeine ingestion compared to placebo for the combined total time of each set and best sprint time. However, the coolest part of this study was that the caffeinated group still had better performance the following day. That’s right, the following day. Caffeine, however, had little effect on reactive agility time or sleep.5 Also, a caffeine-containing energy drink (3 mg/kg wt dose) increased repeated sprint ability during a simulated soccer game.6
Now for those of you with kids, I’m sure you’ve wondered whether these caffeinated sodas like Coca-Cola or Mountain Dew have an effect on performance. OK, I’ve wondered. Well, believe it or not, Mr. Ripley, the data indeed shows something interesting. Twenty-four healthy 8- to 10-year-old boys participated in a randomized double-blind, double-crossover trial. Each boy received the caffeinated drink (5 mg per kg bodyweight) or placebo twice each on four separate visits. Sixty minutes following ingestion of either caffeine or placebo, the boys performed a static hand-grip test and then a Wingate test. A Wingate test is a max sprint test for 30 seconds on a bike. It sounds easy. But I’ll tell you— those 30 seconds seem to crawl slower than a sick cockroach after being sprayed with Raid. Researchers found no differences in peak power or static hand-grip strength with caffeine. However, caffeine significantly increased the average power during a Wingate test.7 So caffeine helps even the little ones.
Put caffeine in a bottle and you’ve got your basic energy drink. What’s interesting is that many of these energy drinks actually have less caffeine than coffee. Yet there are academic numbskulls who believe that energy drinks are akin to a “heart attack in a can.” With billions of cans of this stuff served worldwide, I’d imagine we’d thin the human population quite a bit if indeed these drinks caused harm. Of course, there is no evidence of harm. In fact, energy drinks can profoundly enhance performance. Want proof? Read on …
One study looked at the effects of Red Bull on cardiovascular and neurologic functions in college-aged students enrolled at Winona State University. Researchers found that Red Bull consumption lessens changes in blood pressure during stressful experiences and increases one’s pain tolerance.8 Another study on Red Bull found that upper body muscle endurance on the bench press was improved.9 Similarly, Red Bull improved aerobic endurance (maintaining 65-75% maximum heart rate) and anaerobic performance (maintaining maximum speed) on cycle ergometers. It also helped brain function. Scientists found improvements in mental performance that included choice reaction time, concentration (number cancellation) and memory (immediate recall), which reflected increased subjective alertness.10 Another energy drink, Redline, significantly improved subjective feelings of focus and energy in male strength/power athletes and enhanced their reaction time.11 Despite the naysayers who proclaim energy drinks a threat to heart health and Western civilization, fear not. The stuff works and is safe when used in appropriate dosages.
For real? Caffeine affects hormone levels? Check this out. Forty-two healthy adults were recruited from the Boston community who were regular coffee consumers, nonsmokers and overweight. That’s an interesting trio of things. Participants were randomized to five 6-ounce cups of caffeinated or decaffeinated, instant coffee or water (control group) per day consumed with each meal, mid-morning and mid-afternoon. After four weeks, the consumption of caffeinated coffee increased total testosterone and decreased total and free estradiol in male subjects.12 What does this mean? It means I’m drinking lots of coffee.
Caffeine Is Safe
This stuff is safe. The data shows it, and the fact that I drink gallons of caffeinated coffee every day shows it. In a large cohort of initially healthy women, elevated caffeine consumption was not associated with an increased risk of incident atrial fibrillation.13 Caffeine also helps prevent stress and improves memory.14 Another study found that “coffee drinking may be associated with a decreased risk of dementia/AD. This may be mediated by caffeine and/or other mechanisms like antioxidant capacity and increased insulin sensitivity. This finding might open possibilities for prevention or postponing the onset of dementia/AD.”15 Sounds like a lot of gobbledygook. And I assure you, it might be. But caffeine truly is good for you.
Perhaps one of the biggest myths surrounding caffeine is that its use will have a severe diuretic effect. Interestingly, the science just doesn’t support that. One review states that there is no evidence that consuming caffeine-containing beverages as part of a normal lifestyle leads to fluid loss in excess of the volume ingested or is associated with poor hydration status.16
About 3-5 milligrams of caffeine per kilogram bodyweight will do the trick.17,18 So at the low end of dosing, a 100- and 200-pound person would need to consume 136 and 273 milligrams of caffeine, respectively. At the high end, it would be 227 and 454 milligrams, respectively. Or to make things simple, 200-300 milligrams of caffeine will likely suffice for virtually everyone.
Jose Antonio, Ph.D. is the CEO of the International Society of Sports Nutrition and a professor at Nova Southeastern University’s Exercise and Sports Science Department in Davie, Florida.
- Goldstein ER, Ziegenfuss T, et al. International society of sports nutrition position stand: caffeine and performance. Journal of the International Society of Sports Nutrition 2010;7:5.
- Duncan MJ, Smith M, et al. The acute effect of a caffeine-containing energy drink on mood state, readiness to invest effort and resistance exercise to failure. Journal of strength and conditioning research / National Strength & Conditioning Association 2012;26:2858-65.
- Goldstein E, Jacobs PL, et al. Caffeine enhances upper body strength in resistance-trained women. Journal of the International Society of Sports Nutrition 2010;7:18.
- Ryan EJ, Kim CH, et al. Caffeine Gum and Cycling Performance: A Timing Study. Journal of strength and conditioning research/National Strength & Conditioning Association 2012.
- Pontifex KJ, Wallman KE, et al. Effects of caffeine on repeated sprint ability, reactive agility time, sleep and next day performance. The Journal of sports medicine and physical fitness 2010;50:455-64.
- Del Coso J, Munoz-Fernandez VE, et al. Effects of a caffeine-containing energy drink on simulated soccer performance. PloS one 2012;7:e31380.
- Turley KR, Rivas JD, et al. Effects of caffeine on anaerobic exercise in boys. Pediatric exercise science 2012;24:210-9.
- Ragsdale FR, Gronli TD, et al. Effect of Red Bull energy drink on cardiovascular and renal function. Amino acids 2010;38:1193-200.
- Forbes SC, Candow DG, et al. Effect of Red Bull energy drink on repeated Wingate cycle performance and bench-press muscle endurance. International journal of sport nutrition and exercise metabolism 2007;17:433-44.
- Alford C, Cox H, Wescott R. The effects of red bull energy drink on human performance and mood. Amino acids 2001;21:139-50.
- Hoffman JR, Kang J, et al. Examination of a pre-exercise, high energy supplement on exercise performance. Journal of the International Society of Sports Nutrition 2009;6:2.
- Wedick NM, Mantzoros CS, et al. The effects of caffeinated and decaffeinated coffee on sex hormone-binding globulin and endogenous sex hormone levels: a randomized controlled trial. Nutrition journal 2012;11:86.
- Conen D, Chiuve SE, et al. Caffeine consumption and incident atrial fibrillation in women. The American journal of clinical nutrition 2010;92:509-14.
- Alzoubi KH, Abdul-Razzak KK, et al Caffeine prevents cognitive impairment induced by chronic psychosocial stress and/or high fat-high carbohydrate diet. Behavioral brain research 2013;237:7-14.
- Eskelinen MH, Kivipelto M. Caffeine as a protective factor in dementia and Alzheimer’s disease. Journal of Alzheimer’s disease : JAD 2010;20 Suppl 1:S167-74.
- Maughan RJ, Griffin J. Caffeine ingestion and fluid balance: a review. Journal of human nutrition and dietetics: the official journal of the British Dietetic Association 2003;16:411-20.
- Desbrow B, Biddulph C, et al. The effects of different doses of caffeine on endurance cycling time trial performance. Journal of sports sciences 2012;30:115-20.
- Astorino TA, Cottrell T, et al. Increases in cycling performance in response to caffeine ingestion are repeatable. Nutr Res 2012;32:78-84.