Table 5.
Summary of studies exploring the effects of different doses of caffeine on exercise performance
| Reference | Sample | Caffeine dose | Performance metric | Main findings |
|---|---|---|---|---|
| Anderson et al. [119] | 8 young female rowers | 6 and 9 mg/kg | 2000-m rowing time; average power output | ↓ in rowing time only with 9 mg/kg; ↔ between caffeine and placebo for average power output |
| Arazi et al. [207] | 10 teenage female karate athletes | 2 and 5 mg/kg | Weight lifted in 1 RM leg press; maximum number of repetitions with 60% of 1 RM; vertical jump height; power during ‘Running-based Anaerobic Sprint Test’ | ↔ between the caffeine doses and placebo in any of the analyzed outcomes |
| Astorino et al. [172] | 15 young active men | 2 and 5 mg/kg | Isokinetic knee extension and knee flexion peak torque, average torque, total work, and average power | ↑ in peak knee flexion torque only with 5 mg/kg; ↑ in knee extension and knee flexion total work only with 5 mg/kg; ↑ in knee extension and knee flexion average power only with 5 mg/kg |
| Bruce et al. [208] | 8 male rowers | 6 and 9 mg/kg | 2000-m rowing time | ↓ in rowing time with both caffeine doses; ↔ between caffeine and placebo for average power output |
| Bugyi [209] | 25 young untrained men | 84, 162, 250 mg | Maximum isotonic hand contractions | ↔ between any of the caffeine doses and placebo |
| Cohen et al. [210] | 7 young men and women; the sample comprised competitive road racers | 5 and 9 mg/kg | 21-km road race time trial | ↔ between any of the caffeine doses and placebo |
| Del Coso et al. [211] | 12 young active women and men | 1 and 3 mg/kg | Power output in a half-squat and bench press exercises with loads ranging from 10 to 100% 1 RM | ↑ in power output during the half-squat only with 3 mg/kg; ↑ in power output during the bench press only with 3 mg/kg (for some loads, 3 mg/kg was more effective than placebo; for others, only the 3 mg/kg vs 1 mg/kg comparison was significant) |
| Desbrow et al. [212] | 9 well-trained young male cyclists | 1.5 and 3 mg/kg | Cycling time trial | ↔ between any of the caffeine doses and placebo |
| Desbrow et al. [171] | 16 well-trained young male cyclists | 3 and 6 mg/kg | 1-h cycling time trial | ↓ in cycling time with both caffeine doses |
| Dodd et al. [127] | 17 recreationally trained young men | 3 and 5 mg/kg | Cycling time to exhaustion | ↔ between any of the caffeine doses and placebo |
| Ellis et al. [213] | 15 youth soccer players | 1, 2, and 3 mg/kg | 20-m sprint time, arrowhead agility change of direction; countermovement jump height, peak power, average power, peak velocity, and peak force; Yo–Yo test distance | ↔ between any of the caffeine doses and placebo for 20-m sprint time; ↓ in right change of direction time with all three caffeine doses; ↓ in left change of direction time only with 2 mg/kg of caffeine; ↑ in vertical jump height only with 3 mg/kg; ↑ in peak and mean power as well as peak velocity and force with all three caffeine doses; ↔ between any of the caffeine doses and placebo for Yo–Yo distance |
| Glaister et al. [178] | 17 young male sport science students | 2, 4, 6, 8, and 10 mg/kg | Repeated sprint peak power, mean power, and time to peak power | ↔ between any of the caffeine doses and placebo |
| Graham and Spriet [170] | 8 well-trained young male distance runners | 3, 6, and 9 mg/kg | Running to exhaustion | ↑ in total running time only with 3 and 6 mg/kg |
| Guest et al. [58] | 101 male athletes from various sports | 2 and 4 mg/kg | 10-km cycling time trial | ↓ in cycling time with both caffeine doses |
| Jacobson and Edwards [214] | 36 recreationally active young men and women | 300 and 600 mg | Isokinetic knee extension and knee flexion peak torque | ↔ between any of the caffeine doses and placebo |
| Jenkins et al. [178] | 13 male cyclists | 1, 2, and 3 mg/kg | Work performed during 15-min of cycling | ↑ in work performed only with 2 mg/kg |
| Kovacs et al. [215] | 15 young well-trained triathletes or cyclists | 2.1, 3.2, and 4.5 mg/kg | 1 h cycling time trial | ↑ in cycling mean work output with 3.2, and 4.5 mg/kg enhanced performance as compared to placebo and 2.1 mg/kg of caffeine; ↑ in cycling mean work output with 2.1 as compared to placebo |
| McLellan and Bell [216] | 13 young recreationally active men and women | 3, 5, 6.1, and 7 mg/kg | Running time to exhaustion | ↑ in total running time with all caffeine doses |
| McNaughton [217] | 12 male team sports athletes | 5 and 10 mg/kg | Running time to exhaustion | ↑ in total running time only with 10 mg/kg |
| Miller et al. [202] | 188 young male students | 1 and 3 mg/kg | Forearm flexor MVC | ↑ in MVC strength only with 3 mg/kg |
| Pallarés et al. [173] | 13 young resistance-trained men | 3, 6, and 9 mg/kg | Barbell velocity in the bench press and squat with loads of 25, 50, 75, and 90% of 1 RM; peak power in a 4-s cycling sprint | ↑ in barbell velocity at 25% and 50% of 1 RM with all doses in the bench press and squat; ↑ in barbell velocity at 75% of 1 RM with 6 and 9 mg/kg in the bench press; ↑ in barbell velocity at 90% of 1 RM only with 9 mg/kg in the bench press; ↑ in barbell velocity at 75% of 1 RM with all three caffeine doses in the squat; ↑ in barbell velocity at 90% of 1 RM only with 6 and 9 mg/kg in the squat; ↑ in cycling peak power only with 9 mg/kg |
| Pasman et al. [169] | 9 well-trained young cyclists | 5, 9, and 13 mg/kg | Cycling time to exhaustion | ↑ in total cycling time with all three caffeine doses |
| Perkins and Williams [218] | 14 female young undergraduate students | 4, 7, and 10 mg/kg | Cycling time to exhaustion | ↔ between any of the caffeine doses and placebo |
| Sabol et al. [132] | 20 young recreationally trained men | 2, 4, and 6 mg/kg | Medicine ball throw distance; vertical jump height | ↑ in medicine ball throw distance only with 6 mg/kg; ↑ in vertical jump height with all three caffeine doses |
| Skinner et al. [219] | 10 young competitive male rowers | 2, 4, and 6 mg/kg | 2000-m rowing time; average power output | ↔ between any of the caffeine doses and placebo |
| Stadheim et al. [220] | 8 young trained male cross-country skiers | 3 and 4.5 mg/kg | Cross-country, double poling ergometer time trial | ↑ in total distance covered with both doses of caffeine |
| Tallis and Yavuz [174] | 10 young recreationally active men | 3 and 6 mg/kg | Concentric and eccentric knee extension and elbow flexor strength and total work | ↔ between the caffeine doses and placebo in the elbow flexors in any of the analyzed outcomes; ↑ in knee extension force only at high angular velocity with 6 mg/kg of caffeine; ↔ between any of the caffeine doses and placebo in average concentric, maximal and average eccentric strength of the knee extensors; ↔ between any of the caffeine doses and placebo in strength of the knee extensors during a repeated contractions protocol |
| Trevino et al. [180] | 13 young recreationally active male | 5 and 10 mg/kg | Elbow flexor MVC and rate of torque development | ↔ between any of the caffeine doses and placebo |
| Turley et al. [221] | 26 boys | 1, 3, and 5 mg/kg | Peak and average power during a 30-s Wingate test; handgrip MVC | ↑ in peak power only with 3 mg/kg of caffeine; ↑ in mean power only with 5 mg/kg of caffeine; ↑ in handgrip MVC only with 3 and 5 mg/kg of caffeine |
1 RM 1 repetition maximum, MVC maximal voluntary contraction, ↑ denotes significant increases, ↔ denotes no significant differences, ↓ denotes significant decreases