Table 1.
Characteristics of studies included in the systematic review.
| Authors, Year, (Country) and PEDro Score | Sample Level + |
Caffeine Consumption or Restrictions | Menstrual Cycle and Oral Contraceptives | Timing + Intervention + Washout |
Sample State | Outcomes | R |
|---|---|---|---|---|---|---|---|
| Astorino et al. 2011 (USA) PEDro: 8/10 |
15 NAIA soccer players (19.5 ± 1.1 years) Level: semi-professional | 12/15 were caffeine consumers (dose not reported) Instructed not to ingest any caffeine 48 h before each trial |
Not controlled | 60 min pre-test CAF: Red bull (80 mg: 1.3 mg/kg) PLA: Canada dry ginger ale Washout: 72–96 h |
Rest | Agility t-test: Set 1/3 of 8 reps. | ⇄ |
| Fatigue | Agility t-test: Sets 2 and 3/3 of 8 reps | ⇄ | |||||
| RPE | ⇄ | ||||||
| Del Coso et al. 2013 (Spain) PEDro: 10/10 |
16 rugby sevens National Team (23 ± 2 years)Level: elite |
Light caffeine consumers: <60 mg/day Encouraged to abstain from all dietary sources of caffeine for 48 h before |
Not controlled | 60 min pre-test CAF: Powder caffeine-energy drink 3 mg/kg (Fure®) PLA: Powder drink 0 mg/kg Washout: 72 h |
Rest | 6 × 30 m sprint test | ⇄ |
| Match | Distance covered walking | ⇄ | |||||
| Distance covered jogging | ⇄ | ||||||
| Distance covered cruising | ↑ | ||||||
| Distance covered striding | ↑ | ||||||
| Distance covered high intensity running | ↑ | ||||||
| Distance covered sprinting | ↑ | ||||||
| Match: RPE | ⇄ | ||||||
| Fatigue | 15 s maximal CMJs: total power | ↑ | |||||
| Lee et al. 2014 (Taiwan) PEDro: 10/10 |
11 Division I collegiate team-sport athletes (Basketball or Volleyball) (21.3 ± 1.2 years) Level: semi-professional |
Light caffeine consumers: 50–100 mg/day |
Not controlled | 60 min pre-test CAF: 6 mg/kg capsulesPLA: Cellulose capsules Washout: at least 1 week |
Rest | Agility t-test | ⇄ |
| Fatigue | Cycle-ergometer repeated sprint peak power | ⇄ | |||||
| Cycle-ergometer repeated sprint mean power | ⇄ | ||||||
| Cycle-ergometer repeated sprint total work | ⇄ | ||||||
| Cycle-ergometer repeated sprint decrement | ⇄ | ||||||
| Agility t-test | ⇄ | ||||||
| Blood lactate | ↓ | ||||||
| RPE | ⇄ | ||||||
| Lara et al. 2014 (Spain) PEDro: 10/10 |
18 soccer players (21 ± 2 years) Level: not reported | Light caffeine consumers: not more than one cup of coffee or energy drink per day Encouraged to abstain from all dietary sources of caffeine for 48 h before |
Not controlled | 60 min pre-test CAF: Powder caffeine-energy drink 3 mg/kg (Fure®) PLA: Powder drink 0 mg/kg Washout: 1 week |
Rest | 7 × 30 m sprint average speed | ↑ |
| 7 × 30 m sprint maximal speed | ↑ | ||||||
| CMJ height | ↑ | ||||||
| CMJ Power | ⇄ | ||||||
| Match | Total distance covered | ↑ | |||||
| Time standing | ↑ | ||||||
| Time walking | ⇄ | ||||||
| Time running (3.1–8 km/h) | ↑ | ||||||
| Time running (8.1–13 km/h) | ↑ | ||||||
| Time running (13.1–18 km/h) | ⇄ | ||||||
| Time running (>18 km/h) | ↑ | ||||||
| Number of sprint bouts | ↑ | ||||||
| Maximal speed | ⇄ | ||||||
| RPE | ⇄ | ||||||
| Buck et al. 2015 (Australia) PEDro: 10/10 |
12 amateur team-sports (netball, basketball and soccer) (25.5 ± 1.9 years) Level: amateur |
Caffeine consumption not reported Participants were advised to abstain from consuming CAF for 48 h prior to each trial | 3 days post (follicular phase) menstruation 9 were taking Levlen ED for birth control 3 took no oral contraceptives |
60 min pre-test CAF: Capsule (6 mg/kg BM) PLA: Capsule (1 g glucose) Washout: ≈21 days |
Rest | 6 × 20 m sprint before PSM | ⇄ |
| Best 6 × 20 m sprint before PSM | ⇄ | ||||||
| Total 6 × 20 m sprint time before PSM | ⇄ | ||||||
| Fatigue | 6 × 20 m sprint half-time PSM | ⇄ | |||||
| 6 × 20 m sprint after PSM | ⇄ | ||||||
| Best 6 × 20 m sprint half-time PSM | ⇄ | ||||||
| Best 6 × 20 m sprint after PSM | ⇄ | ||||||
| Total 6 × 20 m sprint time half-time PSM | ⇄ | ||||||
| Total 6 × 20 m sprint time after PSM | ⇄ | ||||||
| RPE during and after PSM | ⇄ | ||||||
| Blood lactate during and after PSM | ⇄ | ||||||
| Chen et al. 2015 (Taiwan) PEDro: 10/10 | 10 elite collegiate athletes (tennis, soccer, basketball) (19.9 ± 0.9 years) Level: semi-professional | No regular caffeine consumption < 200 mg/week | Instructed to participate during their early follicular phase and avoid taking contraception | 60 min pre-test CAF: Capsule 6 mg/kg PLA: Diet flour in capsule Washout: 1 week |
Rest | MVIC | ↑ |
| Isometric fatigue protocol | ↑ | ||||||
| Fatigue | Fatigued MVIC | ↑ | |||||
| Fatigue index | ↑ | ||||||
| Blood lactate | ↓ | ||||||
| Mahdavi et al. 2015 (Iran) PEDro: 10/10 |
24 basketball players (24.2 ± 2.6 years) Level: not reported |
116.8 ± 26.7 mg/day | Not controlled | 70 min pre-test CAF: Capsules 5 mg/kg PLA: Capsules with dextrose Washout: 1 week |
Rest | 30 s WT: Peak power | ⇄ |
| 30 s WT: Mean power | ⇄ | ||||||
| 30 s WT: End power | ⇄ | ||||||
| 30 s WT: Power drop | ⇄ | ||||||
| 30 s WT: Fatigue index | ⇄ | ||||||
| 30 s WT: Lactate | ↑ | ||||||
| Fernandez-Campos et al. 2015 (Costa Rica) PEDro: 9/10 |
19 volleyball players from the elite league of Costa Rica (22.3 ± 4.9 years) Level: elite | Not reported | Not controlled | 30 min pre-test CAF: Energy drink 6 ml/kg with 73 mg of CAF in 273 mL. (1.7 mg/kg) PLA: flavored drink Washout: 1 week |
Rest | Right handgrip strength | ↑ |
| Left handgrip strength | ⇄ | ||||||
| CMJ height | ⇄ | ||||||
| SJ height | ⇄ | ||||||
| WT peak power | ⇄ | ||||||
| WT mean power | ⇄ | ||||||
| WT fatigue index | ⇄ | ||||||
| Perez-Lopez et al. 2015 (Spain) PEDro: 10/10 |
13 volleyball players from the second division of the Spanish league (25.2 ± 4.8) Level: semi-professional |
On the day of the trial participants were encouraged to refrain from all dietary sources of caffeine | 4 during follicular phase9 during luteal phase | 60 min pre-test CAF: Powder energy drink (Fure®) 3 mg/kg PLA: Powder with 0 mg/kg of CAF Washout: 1 week |
Rest | Handgrip | ↑ |
| Spike jump height and peak power | ↑ | ||||||
| Block jump height and peak power | ↑ | ||||||
| Squat jump height and peak power | ↑ | ||||||
| CMJ height and peak power | ↑ | ||||||
| Agility t-test | ↑ | ||||||
| Standing spike ball velocity | ↑ | ||||||
| Jumping spike ball velocity | ↑ | ||||||
| Match | Body accelerations | ↑ | |||||
| Positive game actions | ↑ | ||||||
| Neutral game actions | ⇄ | ||||||
| Negative game actions | ↑ | ||||||
| Body impacts 0–1 g | ↑ | ||||||
| Body impacts 1.1–2 g | ↑ | ||||||
| Body impacts 2.1–3 g | ↑ | ||||||
| Body impacts 3.1–4 g | ⇄ | ||||||
| Body impacts 4.1–5 g | ↑ | ||||||
| Body impacts 5.1–6 g | ↑ | ||||||
| Ali et al. 2016a (New Zealand) PEDro: 10/10 |
10 healthy team sport players (soccer, hockey and netball) (24 ± 4 years) Level: amateur and elite |
Self-reported daily caffeine intake varied from 0 to 300 mg/day | All participants were taking a monophasic oral contraceptive (Monofeme, Microgynon, Levlen ED or Nordette) |
60 min pre-test CAF: Capsules 6 mg/kg PLA: Capsules with artificial sweetener Washout: 13–17 days |
Rest | Knee flexor ecc. PT pre-PSM | ⇄ |
| Knee extensor ecc. PT pre-PSM | ⇄ | ||||||
| Knee flexor ecc. Power pre-PSM | ⇄ | ||||||
| Knee extensor ecc. Power pre-PSM | ⇄ | ||||||
| Isometric knee flexor pre-PSM | ⇄ | ||||||
| Isometric knee extensor pre-PSM | ⇄ | ||||||
| CMJ height and power pre-PSM | ⇄ | ||||||
| Fatigue | Knee flexor ecc. PT mid-PSM | ↑ | |||||
| Knee flexor ecc. PT post-PSM | ⇄ | ||||||
| Knee flexor ecc. PT 12 h-post-PSM | ↑ | ||||||
| Knee extensor ecc. PT mid-PSM | ⇄ | ||||||
| Knee extensor ecc. PT post-PSM | ⇄ | ||||||
| Knee extensor ecc. PT 12 h-post-PSM | ⇄ | ||||||
| Knee flexor ecc. Power mid-PSM | ↑ | ||||||
| Knee flexor ecc. Power post-PSM | ⇄ | ||||||
| Knee flexor ecc. Power 12 h-post-PSM | ↑ | ||||||
| Knee extensor ecc. Power mid-PSM | ↑ | ||||||
| Knee extensor ecc. Power post-PSM | ⇄ | ||||||
| Knee extensor ecc. Power 12 h-post-PSM | ⇄ | ||||||
| Isometric knee flexor mid-PSM | ⇄ | ||||||
| Isometric knee flexor post-PSM | ⇄ | ||||||
| Isometric knee flexor 12 h post-PSM | ⇄ | ||||||
| Isometric knee extensor mid-PSM | ⇄ | ||||||
| Isometric knee extensor post-PSM | ⇄ | ||||||
| Isometric knee extensor 12 h post-PSM | ⇄ | ||||||
| CMJ height and power post-PSM | ⇄ | ||||||
| CMJ height and power 12 h post-PSM | ⇄ | ||||||
| Ali et al. 2016b (New Zealand) PEDro: 10/10 |
10 healthy team sport players (soccer, hockey and netball) (24 ± 4 years) Level: amateur and elite | Self-reported daily caffeine intake varied from 0 to 300 mg/day | All participants were taking a monophasic oralcontraceptive | 60 min pre-test CAF: Capsules 6 mg/kg PLA: Capsules with artificial sweetener Washout: 13–17 days |
Fatigue | RPE | ⇄ |
| Portillo et al. 2017 (Spain) PEDro: 10/10 |
16 rugby sevens national team players (23 ± 2 years) Level: elite | Light caffeine consumers: <60 mg/day | Not controlled | 60 min pre-test CAF: Powder 3 mg/kg PLA: Powder with 0 mg/kg of CAF Washout: 72 h |
Match | Body impacts 0–6 g | ↑ |
| Body impacts 6.01–6.5 g | ↑ | ||||||
| Body impacts 6.51–7 g | ↑ | ||||||
| Body impacts 7.01–8 g | ⇄ | ||||||
| Body impacts 8.01–10 g | ↑ | ||||||
| Body impacts > 10 g | ⇄ | ||||||
| Frequency of technical action | ⇄ | ||||||
| Ratings of skill performance | ⇄ | ||||||
| Puente et al. 2017 (Spain) PEDro: 10/10 |
10 professional basketaball players (27.9 ± 6.1 years) Level: semi-professional and elite |
Light caffeine consumers < 100 mg/day Encouraged to abstain from CAF ingestion during the study |
All participants were tested during their luteal phase | 60 min pre-test CAF: Capsule 3 mg/kgPLA: Capsule 0 mg/kg of CAF Washout: 1 week |
Rest | Abalakov jump | NA |
| CODAT | |||||||
| Free throws | |||||||
| CODAT with ball | |||||||
| Match | Body impacts 0–0.99 g | ||||||
| Body impacts 1–1.99 g | |||||||
| Body impacts 2–2.99 g | |||||||
| Body impacts 3–3.99 g | |||||||
| Body impacts 4–4.99 g | |||||||
| Body impacts >5 g | |||||||
| RPE | |||||||
| Pfeifer et al. 2017 (USA) PEDro: 8/10 |
8 volleyball NAIA volleyball (18–22 years)Level: semi-professional |
CAF consumption was not restricted | Not controlled | Prior to and during the competition CAF: PowerBar® PowerGel® 50 mg of caffeine. Averaged 1.39 mg/kg PLA: Non-nutritive gel Washout: ≈1 week |
Fatigue | Vertical jump with a two-step approach | ⇄ |
| Three cone drill agility | ⇄ | ||||||
| 6 × 30 m sprint | ⇄ | ||||||
| Stojanovic et al. 2019 (Serbia) PEDro: 10/10 |
10 professional basketball players (20.2 ± 3.9 years) Level: elite |
Light caffeine consumers: <100 mg/day | Completed testing in the luteal phase of their menstrual cycle Use of oral contraceptives not reported by authors |
60 min pre-test CAF: Capsule (3 mg/kg BM) PLA: Capsule (Dextrose) Washout: 1 week |
Rest | CMJ height | ⇄ |
| SJ height | ⇄ | ||||||
| ABA height | ⇄ | ||||||
| Lane agility | ⇄ | ||||||
| 5 m sprint | ⇄ | ||||||
| 10 m sprint | ↑ | ||||||
| 20 m sprint | ↑ | ||||||
| 5 m sprint-dibbling | ⇄ | ||||||
| 10 m sprint-dibbling | ⇄ | ||||||
| 20 m sprint-dibbling | ⇄ | ||||||
| RSP: Suicide run | ⇄ | ||||||
| RPE | ↑ | ||||||
| Tan et al. 2020 (Singapore) PEDro: 8/10 |
6 basketball players Level: semi-professional |
Less than 200 mg caffeine per day | Not controlled | 60 min pre-test CAF: Powders (6 mg/kg BM) PLA: Powders (Maltodextrine) Washout: 72 h |
Fatigue | Free throws | NA |
| RPE | |||||||
| Muñoz et al. 2020 (Spain) PEDro: 10/10 |
15 elite handball players (22.6 ± 3.6 years) Level: elite |
Light caffeine consumers: 50 ± 30 mg/day | 10 during follicular phase 5 during luteal phase Use of oral contraceptives not reported by authors |
60 min pre-test CAF: Capsule (3 mg/kg BM) PLA: Capsule (Cellulose) Washout: 1 week |
Rest | 7m ball throws | ↑ |
| 9m ball throws | ↑ | ||||||
| 7m ball throws goalk. | ↑ | ||||||
| 9m ball throws goalk. | ↑ | ||||||
| CMJ height | ↑ | ||||||
| Handgrip | ↑ | ||||||
| Agility: MATT | ⇄ | ||||||
| 30m sprint | ↑ | ||||||
| Match | Accelerations frequency | ↑ | |||||
| Decelerations frequency | ↑ | ||||||
| Body impacts | ↑ | ||||||
| Total distance | ⇄ | ||||||
| Sprint distance | ⇄ | ||||||
| Maximal speed | ⇄ | ||||||
| RPE | ⇄ | ||||||
| Karayigit et al. 2021 (Turkey) PEDro: 10/10 |
17 female team sports (rugby, handball and soccer) 23 ± 2 years) Level: elite and semi-professional |
Light caffeine consumers: <25 mg/day | All sessions were performed during the luteal phase of the menstrual cycle All subjects stopped oral contraceptive consumpletion 3 months before the commencement of the study |
60 min pre-test CAF: Coffee (3 mg/kg BM) (6 mg/kg BM) PLA: Decaffeinated coffee Washout: 48–72 h |
Rest | 3 set of repetitions to failure 40% 1 RM bench press | ↑ |
| 3 set of repetitions to failure 40% 1 RM squat | ⇄ |
↑: caffeine supplementation improved performance (for variables like lactate levels, standing time or sprint times this would entail a lower lactate increase or a lower sprint and standing time); ⇄: no differences between placebo and caffeine groups; ↓: caffeine supplementation decreased performance (for variables like lactate levels, standing time or sprint times this would entail a higher lactate increase or a higher sprint and standing time). + If the participant’s category was described as recreational or amateur, the sport level was classified as amateur. If the player’s category in each study was described as collegiate or second division, the sport level was classified as semi-professional. If the player’s category in each study was elite (national team) or professional, the sport level was classified as elite. ABA: Abalakov jump; BM: body mass; CAF: caffeine group; CMJ: countermovement jump; CODAT: change-of-direction and acceleration test; Ecc.: eccentric; Goalk.: drill performed with a goalkeeper; ISOfatig: submaximal voluntary isometric fatigue protocol; Lane agility: lane agility drill; Match: match following official rules; MATT: modified version of the agility t test; MVIC: maximal volumetric isometric contractions; MVICpost: voluntary isometric contraction after fatigue protocol; NA: not applicable because the statistical analyses presented in the studies were performed for males and females without an individual comparison for females; NAIA: National Association of Intercollegiate athletics; Perc. Performance: perceived performance; PLA: placebo; PSM: protocol simulating the fatigue generated during a match; PT: peak torque; R: results; RPE: rate of perceived exertion; RSP: repeated sprint performance; SF: sodium phosphate; SJ: squat jump; SM: simulated match; SP: self-perceived; WT: Wingate test.