When developing your fueling and hydration plan for an ultramarathon, you also need to take into account how much caffeine you’re ingesting — and in what stages of the race. Many energy gels, chews, and bars come with added caffeine, which makes it easy to over consume caffeine unless you’re strategically using those sports nutrition products with an eye on your individual sensitivity and needs. So how much caffeine is the right amount?
Caffeine During Ultramarathons
According to the International Society of Sports Nutrition, “Evidence supports the strategic use of caffeine to sustain performance in the latter stages of [ultramarathon] racing, particularly when sleep deprivation may compromise athlete safety” (Tiller et al. 2019: 2).
Caffeine has been demonstrated to have ergogenic properties — that is, properties that enhance physical performance — in a variety of sports (Burke 2008; Goldstein et al. 2010). The ergogenic effects include both “improved cognitive function and concentration” and enhancements to muscle contraction (Tiller et al. 2019: 15-16). But for ultramarathoners, the stimulant properties are likely most important, especially for races that last 24 hours or longer “when sleep deprivation will affect performance and athlete safety” (Tiller et al. 2019: 16).
To mitigate side effects, avoid large doses of caffeine. “If frequent doses are to be taken during ultra-marathon, then lower (more sustainable) amounts (e.g., 1–2 mg/kg; 70–140 mg for a 70 kg athlete) are more appropriate and safer over several hours” (Tiller et al. 2019: 16).
Given the important stimulant properties of caffeine, ultramarathoners “are encouraged to target any caffeine intake for the latter stages of competition” (Tiller et al. 2019: 16). This means waiting until you’re sleepy during a full day race to start ingesting those sports nutrition products with added caffeine.
Repeated doses of 50 mg per hour “are likely to be well-tolerated, principally reserved for night-running when circadian rhythms are likely to be affected” (Tiller et al. 2019: 16).
In events lasting 24 hours or longer where you’re running through the night, wait until midnight to start ingesting caffeinated products; then continue with up to 50 mg/hr or up to 1-2 mg of caffeine per kilogram of body weight for 3-4 hours, stopping the caffeine intake after sunrise.
In events from 50K to 50 miles, wait until the second half of the race to consume caffeine. In events shorter than six hours, wait until the second or third hour before beginning to consume caffeine.
Be sure to take into account your individual sensitivity to caffeine and practice during training what you plan to do during competition.
More Caffeine is Not Necessarily Better
Keep in mind these two key points about caffeine:
- Dose response. Your body’s response to caffeine intake “is not linear (i.e., larger caffeine doses do not necessarily confer greater performance)” (Tiller et al. 2019: 16).
- Side effects. Too much caffeine causes side-effects that may include gastrointestinal distress, headaches, and anxiety (Tiller et al. 2019: 16; Thomas et al. 2016: 560).
As with any aspect of your ultramarathon fueling and hydration plan, “Caffeine strategies should, therefore, be carefully planned and practiced in advance of competition” (Tiller et al. 2019: 16).
Given the “dangerous effects of caffeine overconsumption, athletes are advised to double-check their doses, ensure their intakes are congruent with the empirical data and safety guidelines, and give special consideration to the method of delivery (fluid vs. tablets vs. gum)” (Tiller et al. 2019: 16).
Individual Variation in Caffeine Use
Two studies have documented the actual practices of elite ultramarathoners, providing insight into how much caffeine was ingested over the course of entire ultramarathons. One point to keep in mind is that both studies provide numbers for caffeine intake per hour as though caffeine intake held steady over the total hours of the races. But unlike the average hourly intake of carbohydrates, caffeine intake during long events is more likely to be skewed toward the latter stages of those events. This means it’s likely that the per hour numbers may be lower earlier in the races and higher later in the races.
Stellingwerff (2016) tracked the nutrition practices of three elite male ultrarunners during 100-mile ultramarathons over the course of a season (16 ultramarathons in total). They found that the athletes consumed on average 912 mg (+/- 322 mg) of caffeine over 15-19 hours of running, which amounted to 0.9 mg (+/- 0.27 mg) of caffeine per kilogram of bodyweight per hour (the average weight of the participants was 59.5 kg or 131 pounds) and 55 mg (+/- 22 mg) each hour (over an average of 16.7 hours). Although the study does not say whether this was consistently dosed over the entire race or weighted toward the end, the hourly average (if consistently dosed) is slightly higher than the 50 mg/hour amount that Tiller and colleagues suggest is “likely to be well-tolerated” (Tiller et al. 2019: 16).
Lavoué and colleagues (2020) analyzed the nutrition practices of 12 elite ultrarunners (six males and six females) during a 24-hour ultramarathon and found their total caffeine intake averaged 5.04 mg (+/- 3.77 mg) of caffeine per kilogram of body weight, or 12.8 mg (+/- 10.1 mg) of caffeine per hour (the average weight of the participants was 61.1 kg or 135 pounds). This is quite a bit lower than what Stellingwerff (2016) found, but the sample size is larger and the racing time longer. It’s unlikely that this represents a consistent per hour dosage over the full 24 hours; the per hour intake is likely lower in the early stages of the race and higher in the latter stages, in line with the general strategy recommended by Tiller and colleagues (2019). If the total average caffeine intake were distributed across 6 hours of the race representing nighttime running (rather than the full 24 hours); then it would amount to 51 mg/hour.
But I believe a more important takeaway from these studies is the range of individual variation of caffeine use among the study participants. Caffeine use and tolerance must be individually determined. Some individuals need one or two cups of coffee to start their days. Others get jittery when they drink coffee or can’t get to sleep if they drink coffee later in the day. Your experience and sensitivity to caffeine in daily life is an important starting point for determining how much, if any, caffeine you might include in your race nutrition plan. Both studies are interesting in the ranges of consumption that were found, which underscores quite a bit of individual variation in the use of caffeine.
In the Stellingwerff (2016) study, the total caffeine intake ranged from a low of 625 mg to a high of 1,260 mg. The average amount of caffeine ingested per hour ranged from 42 mg/hr to 80 mg/hr. The amount of caffeine ingested per kilogram per hour ranged from 0.72 mg/kg/hr to 1.20 mg/kg/hr.
In the study by Lavoué and colleagues (2020), the total caffeine intake ranged from a low of 1.01 mg/kg of body weight (or 61.7 mg) to a high of 10.9 mg/kg of body weight (or 666 mg). The average amount of caffeine ingested per hour ranged from 2.4 mg/hr to 32.9 mg/hr. If the per hour ranges were distributed across 6 hours of the race (rather than the full 24 hours); then the per hour consumption would range from 9.6 mg/hr to 131.6 mg/hr.
The ranges illustrate the wide variation among elite ultrarunners in their caffeine intake during ultramarathons. Caffeine is certainly not necessary or required to do well at these distances. Individual sensitivity, tolerance, and preference must be considered before simply adding caffeinated sports nutrition products to your race day nutrition plan.
Calculating Your Caffeine Target
Now that you have some numbers in mind, let’s see how those numbers relate to the amount of caffeine in actual sports nutrition products.
Again, here’s a summary of the International Society of Sports Nutrition guidelines for ultrarunners (Tiller et al. 2019):
- Wait to use caffeine in the latter stages of a race, especially during night running.
- 1-2 mg/kg of body weight would be appropriate over several hours (e.g., 130-pound runner = 59-118 mg caffeine; 160-pound runner = 73-146 mg caffeine; 190-pound runner = 86-172 mg caffeine).
- 50 mg caffeine per hour is generally well-tolerated.
- Consider your individual sensitivity and double-check your doses.
With these guidelines in mind, look at the amount of caffeine in the products below (and the ones you use) to determine how much and how often you want to consume them to stay within your individual target for caffeine intake.
Caffeine in common drinks and chocolate:
- Percolated coffee (7 fluid ounces) = 80-135 mg
- Drip coffee (7 fluid ounces) = 115-175 mg
- Espresso (1.5-2.0 fluid ounces) = 100 mg
- Red Bull (8.5 fluid ounces) = 80 mg
- Mountain Dew (12 fluid ounces) = 54 mg
- Coca-Cola (12 fluid ounces) = 34 mg
- Black/green tea (6 fluid ounces) = 22-74 mg
- Hershey’s Special Dark (45% cacao, 1.5-ounce bar) = 31 mg
- Hershey’s Milk Chocolate (11% cacao, 1.5-ounce bar) = 10 mg
Gels with added caffeine:
- Clif Shot Double Espresso = 100 mg
- SiS gel with caffeine = 75 mg
- Gu Roctane Coffee gel = 70 mg
- Clif Shot Mocha = 50 mg
- Gu Cola Me Happy gel = 40 mg
- Gu Roctane gels with caffeine = 35 mg
- Clif Shot Citrus or Strawberry = 25 mg
- Gu Chocolate/Vanilla/Caramel/Tri-Berry gels = 20 mg
Bars with added caffeine:
- Clif Builders Protein + Caffeine = 60 mg
- Clif Bar Cool Mint Chocolate = 49 mg
Energy chews with added caffeine:
- Clif Bloks Black Cherry = 50 mg
- Honey Stinger Cherry Cola = 50 mg
- Clif Bloks Tropical Punch or Orange = 25 mg
Other sports nutrition product with caffeine:
- Tailwind Recovery Mix Coffee Caffeinated = 80 mg
- Tailwind Endurance Fuel Tropical/Raspberry Caffeinated = 70 mg
- Gu Caramel Coffee Stroopwafel = 20 mg
Use Caffeine Strategically
Caffeine, in safe amounts, can be useful during ultramarathon racing. Given its stimulant properties, ingesting caffeine in the latter stages of an ultramarathon may be helpful in dealing with fatigue associated with sleep deprivation during night running. But not everyone responds equally to caffeine and simply ingesting more does not lead to better performance. Practice during training to find what works for you, taking into consideration the recommendations from the International Society of Sports Nutrition discussed in this article.
References
Burke, Louise M. 2008. “Caffeine and sports performance.” Applied Physiology, Nutrition, and Metabolism 33(6): 1319–34. DOI: 10.1139/H08-130
Goldstein, ER; T Ziegenfuss; D Kalman; R Kreider; B Campbell; C Wilborn; L Taylor; D Willoughby; J Stout; BS Graves; R Wildman; JL Ivy; M Spano; AE Smith; and J Antonio. 2010. “International Society of Sports Nutrition Position Stand: Caffeine and Performance.” Journal of the International Society of Sports Nutrition 7(1): 5. DOI: 10.1186/1550-2783-7-5
Lavoué, Chloé; Julien Siracusa; Émeric Chalchat; Cyprien Bourrilhon; and Keyne Charlot. 2020. “Analysis of food and fluid intake in elite ultra-endurance runners during a 24-h world championship.” Journal of the International Society of Sports Nutrition 17(36). DOI: 10.1186/s12970-020-00364-7
Stellingwerff, Trent. 2016. “Competition Nutrition Practices of Elite Ultramarathon Runners.” International Journal of Sport Nutrition and Exercise Metabolism 26: 93-99. DOI: 10.1123/ijsnem.2015-0030
Thomas, DT; KA Erdman KA; and LM Burke. 2016. “American College of Sports Medicine Joint Position Statement. Nutrition and Athletic Performance.” Medicine & Science in Sports & Exercise 48(3): 543-68. DOI: 10.1249/MSS.0000000000000852
Tiller, NB; JD Roberts; L Beasley L; S Chapman; JM Pinto; L Smith; M Wiffin; M Russell; SA Sparks; L Duckworth; J O’Hara; L Sutton; J Antonio; DS Willoughby; MD Tarpey; AE Smith-Ryan; MJ Ormsbee; TA Astorino; RB Kreider; GR McGinnis; JR Stout; JW Smith; SM Arent; BI Campbell; and L Bannock. 2019. “International Society of Sports Nutrition Position Stand: Nutritional considerations for single-stage ultra-marathon training and racing.” Journal of the International Society of Sports Nutrition 16(1): 50. DOI: 10.1186/s12970-019-0312-9
