تاثیر مصرف مکمل کافئین، کارنیتین و کافئین- کارنیتین بر سطح اسید لاکتیک و رکورد شنای 400 متر کرال سینه شناگران دختر نوجوان

Background: The study aim was to examine the effect of caffeine, L-carnitine, and their combination on lactate blood level, and exercise time during a 400m freestyle swimming trial. Methods: In a double-blind randomly designed study, 16 Karaj female freestyle swimmers aged 13.87&plusmn;1.14 yr, BMI 21.69&plusmn;4.34 kg/m2, height 160.87&plusmn;58.75cm, weight 56.31&plusmn;1.31kg were recruited. The trial activities included completing maximal 400m freestyle. The activity was performed half an hour after taking caffeine (3 mg/kg body weight) or L-carnitine (1.5g), caffeine + L-carnitine (3 mg/kg + 1.5 g), or placebo on 4 similar separate occasions. Blood lactate was measured 1 and 10 min after exercise. Results: Repeated measures ANOVA indicated that no significant difference was observed for performance in&nbsp; all groups (p&ge;0.05), whereas significant differences were observed in lactate accumulation in 1 min after trial (p<0.05). Conclusion: These findings showed that consuming caffeine, L-carnitine and their combination has no meaningful effect on performance. However, it seems that taking caffeine alone or with L-carnitine result would result in more lactate accumulation in 1 min after exercise. &nbsp;