King Grub
2018-11-15, 13:28
PURPOSE::
Inconsistent results among studies examining the effects of caffeine on exercise performance are potentially due to inter-individual variability in biological responses to caffeine ingestion. The aims, therefore, of the present study were to identify high and low caffeine responders and compare the influence of caffeine on exercise performance and biological responses between groups during a simulated soccer-game protocol on treadmill.
METHODS::
Well-trained soccer-players were distinguished as high (n = 11) and low (n = 9) caffeine responders based on resting blood pressure, plasma glycerol, non-esterified fatty acid and epinephrine responses to caffeine. Participants underwent two simulated soccer-game protocols on treadmill after caffeine (6 mg∙kg-1) or placebo ingestion. Exercise performance and several biological responses were evaluated.
RESULTS::
Exercise performance was not different between the high (H) and low (L) responders to caffeine (P > 0.05). However, time-to-fatigue (H, caffeine: 797±201 s vs placebo: 487±258 s; L, caffeine: 625±357 s vs placebo 447±198 s) and countermovement jumps (H, caffeine: 42.1±5.5 cm vs placebo: 40.5±5.7 cm; L, caffeine: 41.0±3.8 cm vs placebo: 38.8±4.6 cm) improved with caffeine relative to placebo (P < 0.001). Rating of perceived exertion was lower (P < 0.001) in H (13.4±2.3) compared to L (14.3±2.4) with caffeine ingestion.
CONCLUSIONS::
Caffeine improved aerobic endurance and neuromuscular performance in well-trained soccer-players regardless of their responsiveness to caffeine at rest. Since no changes in substrate utilization were found with caffeine supplementation, performance improvements could be attributed to positive effects on the central nervous system and/or neuromuscular function, although the precise mechanism remains unclear.
Int J Sports Physiol Perform. 2018 Nov 14:1-25. Caffeine Supplementation: Ergogenic in Both High and Low Caffeine Responders.
Inconsistent results among studies examining the effects of caffeine on exercise performance are potentially due to inter-individual variability in biological responses to caffeine ingestion. The aims, therefore, of the present study were to identify high and low caffeine responders and compare the influence of caffeine on exercise performance and biological responses between groups during a simulated soccer-game protocol on treadmill.
METHODS::
Well-trained soccer-players were distinguished as high (n = 11) and low (n = 9) caffeine responders based on resting blood pressure, plasma glycerol, non-esterified fatty acid and epinephrine responses to caffeine. Participants underwent two simulated soccer-game protocols on treadmill after caffeine (6 mg∙kg-1) or placebo ingestion. Exercise performance and several biological responses were evaluated.
RESULTS::
Exercise performance was not different between the high (H) and low (L) responders to caffeine (P > 0.05). However, time-to-fatigue (H, caffeine: 797±201 s vs placebo: 487±258 s; L, caffeine: 625±357 s vs placebo 447±198 s) and countermovement jumps (H, caffeine: 42.1±5.5 cm vs placebo: 40.5±5.7 cm; L, caffeine: 41.0±3.8 cm vs placebo: 38.8±4.6 cm) improved with caffeine relative to placebo (P < 0.001). Rating of perceived exertion was lower (P < 0.001) in H (13.4±2.3) compared to L (14.3±2.4) with caffeine ingestion.
CONCLUSIONS::
Caffeine improved aerobic endurance and neuromuscular performance in well-trained soccer-players regardless of their responsiveness to caffeine at rest. Since no changes in substrate utilization were found with caffeine supplementation, performance improvements could be attributed to positive effects on the central nervous system and/or neuromuscular function, although the precise mechanism remains unclear.
Int J Sports Physiol Perform. 2018 Nov 14:1-25. Caffeine Supplementation: Ergogenic in Both High and Low Caffeine Responders.