Effects of dark chocolate on physiological attributes and anaerobic performance among healthy females and males

To investigate the effects of dark chocolate milk on physiological variables such as heart rate (HR), rate of perceived exertion (RPE), fatigue index and power output during an anaerobic sprint test.

Methods: Twenty healthy participants (males: age: 23.8 ± 1.21 yrs; height: 174.51 ± 5.78 cm; weight: 73.91 ± 9.18 kg; body mass index (BMI): 24.18 ± 2.21 kg·m-2; body fat percent (BF%): 19.18 ± 6.17 %; lean muscle mass percentage: 77.95 ± 6.16 %; females: age: 26.33 ± 4.95 yrs; height: 160.69 ± 5.52 cm; weight: 55.72 ± 7.03 kg; BMI: 21.51 ± 2.02 kg·m-2; BF%: 27.24 ± 3.74 %; lean muscle mass percentage: 69.20 ± 3.70 %)) underwent a randomised single-blinded experimental design and completed 2 trials – DC and white chocolate (WC) . Participants completed a Running Anaerobic Sprint Test (RAST, 35m x 6 sprints) with RPE and HR recorded after 2nd, 4th and 6th sprint. They rested for 4 minutes and continued 2nd RAST.

Results: Paired t-test revealed significant differences between trials for 2nd RAST average timings (DC 2nd RAST: 6.43 ± 0.97 s vs WC 2nd RAST: 6.62 ± 1.05 s, p = 0.012); 2nd RAST total effort time (DC 2nd RAST: 38.58 ± 5.82 s vs WC 2nd RAST: 39.72 ± 6.28 s, p = 0.012; within trials for HR (DC 1st RAST HR 6th set: 168.75 ± 7.23 beats·min-1 vs DC 2nd RAST HR 6th set: 176.60 ± 7.72 beats·min-1, p = 0.000; WC 1st RAST HR 6th set: 170.15 ± 9.18 beats·min-1 vs WC 2nd RAST HR 6th set: 173.50 ± 7.92 beats·min-1, p = 0.010); within trials for RPE (DC 1st RPE 6th set: 7.85 ± 1.31 vs DC 2nd RAST RPE 6th set: 8.90 ± 0.97, p = 0.001; WC 1st RAST RPE 6th set: 7.90 ± 1.29 vs WC 2nd RAST RPE 6th set: 8.90 ± 1.17, p = 0.001). There were no significant differences found between DC 1st and 2nd RAST average timings (DC 1st RAST: 6.46 ± 0.98 s vs DC 2nd RAST: 6.43 ± 0.97 s, p = 0.453); WC 1st and 2nd RAST average timings (WC 1st RAST: 6.42 ± 0.77 s vs WC 2nd RAST: 6.62 ± 1.05 s, p = 0.049); DC and WC 1st RAST RPE: (DC 1st RAST RPE: 7.85 ± 1.31 vs WC 1st RAST RPE: 6.42 ± 0.77, p = 0.841); DC and WC 2nd RAST RPE: (DC 2nd RAST RPE: 8.90 ± 0.97 vs WC 2nd RAST RPE: 8.90 ± 1.17, p = 1.000).

Conclusion: Results indicated that DC supplementation significantly improved anaerobic sprint timings. Elite athletes, sports practitioners and coaches may consider implementing DC prior to training workouts and competitions to enhance sporting performance.