Table 1 The effect of CF supplementation on exercise-induced oxidative stress
Reference | Participants | Nutritional intervention | Supplementation period | Exercise stimulus | Measure(s) | Key outcome(s) |
|---|---|---|---|---|---|---|
Allgrove et al. [42] | 20 healthy males Age 22 ± 4 years Mass 74.6 ± 8 kg V̇O2max 53.1 ± 7.0 ml·kg−1 Power output 300 ± 30 W | CF: 80 g dark chocolate a day for 14 days, 197.4 mg CF per dose (EPI: 77.4 mg, CAT: 31.2 mg) CON: 56.8 g iso-CHO-fat control chocolate, 0 mg CF | Each day for 14 days, with a half dose 2 h pre-exercise | Cycling at 60% V̇O2max for 1.5 h, intensity raised to 90% every 10 min for 30 s 5 min post cycling there was a time to exhaustion trial at 90% V̇O2max | (i) F2-isoprostanes (ii) Oxidised LDLs (iii) Plasma uric acid (iv) TEAC (v) Plasma vitamin C | (i) significantly ↓ in CF group (ii) significantly ↓ across each time point in CF group (iii) ↑ post-exercise in both treatments (iv) ↔ between groups (v) ↔ between groups |
Davison et al. [47] | 14 healthy males Age 22 ± 1 years Mass 71.6 ± 1.6 kg V̇O2max 53.1 ± 1.9 ml·kg−1 min−1 Power output 300 ± 12 W | CF: 100 g dark chocolate 246.8 mg CF (EPI: 96.8 mg, CAT: 39.1 mg) CON: isomacronutrient control, 0 mg CF None: water | Acute dose 2 h pre-exercise | Cycling at ~ 60% V̇O2max for 2.5 h | (i) F2-isoprostanes (ii) Plasma Vitamin C (iii) TEAC | (i) ↓ CF group vs CON (ii) ↔ between groups (iii) ↑ pre-exercise CF vs CON |
de Carvalho et al. [49] | 13 trained males Age 21 ± 2 years Stature 180 ± 0.05 cm Mass 87.02 ± 8.03 kg | CF: CHO + protein cocoa beverage, 306 mg CF per beverage CON: cocoa based CHO + protein beverage, 0 mg CF | 7 days, beverage consumed twice daily | Five sets of 20 drop jumps from 0.6 m, 10 s between jumps and 2 min interset rest | Urinary F2-isoprostanes |  ↔ between groups |
Decroix et al. [43] | 12 well-trained males Age 30 ± 3 years Stature 177.9 ± 8.8 cm Mass 72.8 ± 7.8 kg V̇O2max 63.0 ± 3.5 ml·kg−1 min−1 | CF: cocoa drink, 900 mg CF (EPI: 185 mg, CAT: 20 mg) CON: placebo, 15 mg CF (EPI: 0 mg, CAT: 0 mg) | Acute dose 1.5 pre-exercise | Two 30 min time trials 60 min apart, performed at a ~ 75% peak power output | (i) Uric acid (ii) MDA (iii) TEAC | (i) ↑ in CF vs CON (ii) ↔ between group (iii) ↑ in CF vs CON |
Decroix et al. [45] | 14 well-trained males Age 31 ± 3 years Stature 180 ± 5 cm Mass 73 ± 7 kg V̇O2max 62.9 ± 5.8 ml·kg−1 min−1 Peak Power Output 366 ± 45 W | CF: Capsule, 530 mg CF (EPI: 100 mg, CAT: 21 mg) CON: 1,764 mg maltodextrin | Consumed daily for six days and then a seventh on the day of testing | 20 min steady state cycling at 45% peak power output 20 min time trial beginning at 75% peak power output Completed in normoxic and hypoxic environments | (i) TEAC (ii) Uric acid (iii) MDA | (i) ↔  (ii) ↔  (iii) CF blunted ↑ in both N and H |
Fraga et al. [41] | 28 trained males Age 18 ± 1 years Mass 74 ± 1 kg | CF: 105 g chocolate confectionery, 168 mg CF (EPI + CAT: 39 mg) CON: 105 g cocoa butter chocolate, < 5 mg CF | Sub-chronic, 14 day consumption | Soccer training sessions twice per week and one match per week | (i) MDA (ii) Urate (iii) Oxo8dG (iv) TRAP (v) α-tocopherol (vi) lycopene vii) β-carotene (viii) coenzyme Q-10 | (i) Post CF ↓ by 12% CON ↑ by 10% (ii) ↓ by 11% in CF (iii-viii) ↔ between groups |
Morgan et al. [48] | 10 active males Age 23 ± 3 years Stature 184 ± 59 cm Mass 85.3 ± 12.0 kg Single leg 1RM 90.4 ± 19.0 kg | CF: 330 ml cacao juice, 74 mg CF (EPI: 8 mg, CAT: 43 mg) CON: 330 ml CHO and flavour matched placebo, 0 mg CF | 10 days supplementation (7 days pre-exercise, 3 days post) | 10 sets of 10 single leg knee extensions at ~ 80% 1RM | Protein carbonylation | Protein carbonylation not elevated following exercise protocol |
Taub et al. [50] | 17 sedentary (9 males 8 females) participants CF: Age 50 ± 3 Stature 168 ± 3 Mass 78.8 ± 5.6 V̇O2max 22.9 ± 1.9 ml·kg−1 min−1 CON: Age 50 ± 2 Stature 175 ± 5 Mass 92.2 ± 9.7 V̇O2max 24 ± 1.7 ml·kg−1 min−1 | CF: 20 g dark chocolate, 175.2 mg CF (EPI: 26 mg, CAT: 4.6) CON: 20 g placebo chocolate | Chronic (3 months daily intake) | Cycling exercise including V̇O2max | (i) GSH:GSSG ratio (ii) Protein carbonylation | (i) significant ↑ in CF group vs CON (ii) significant ↓ in CF group vs CON |
Wiswedel et al. [44] | 20 untrained males Age ~ 20–25 | CF: cocoa drink, 185 mg CF CON: cocoa drink 14 mg CF | Acute, 2 h pre cycling exercise | Cycling at 75 W increasing to 150 W for 10 min | (i) F2-isoprostanes (ii) MDA (iii) α-tocopherol (iv) ascorbate (v) TAC | (i) CON small ↑ 2 and 4 h post-consumption, CF did not Significant difference CF vs CON 2 and 4 h post-intake following exercise (ii–v) ↔ between groups |