Effects of chronic L-carnitine supplementation on exercise performance and blood lactate in resistance-trained males
Majid S Koozehchian1, Amin Daneshfar2, Mozhgan Hassanzadeh3, Maryam Kaveh4, Ebrahim Fallah2, Conrad P Earnest FACSM1,5, Gholamali Owlia6, Mike Greenwood FACSM1, Richard B Kreider FACSM1
1Exercise & Sport Nutrition Lab, Human Clinical Research Facility, Department of Health & Kinesiology, Texas A&M University, College Station, TX 77843 USA
2Kinesiology, Tarbiat Modares University, Tehran, 14115-111 Iran
3Department of Kinesiology, Azad University, Central Branch, Tehran, Iran
4Department of Pharmaceutical Practice, Karnataka College of Pharmacy, Bangalore, India
5Nutrabolt, Bryan, TX 77807, USA
6Department of Health & Kinesiology, Texas Southern University, Houston, TX 77004 USA
Corresponding author: [email protected]
Background
The purpose of this study was to examine the long-term effects of ingesting L-Carnitine supplement on exercise performance and blood lactate levels.
Method
In a randomized, placebo-controlled, double-blind design, 35 male participants (age = 25 ± 2 y; stature = 171 ± 6 cm; body mass = 79.8 ± 8.9 kg; percent body fat = 16.1 ± 5.53%; Control [CON] n = 12, Placebo [PLA] n = 11, L-carnitine [LCR] n = 12) participated in the study. Primary outcomes were total body strength performance, anaerobic performance, and pre- and post-exercise (minutes three, fifteen, and thirty) blood lactate (BL) levels which were measured at baseline and at weeks 3, 6, and 9. All participants were asked to maintain their normal dietary intake during the study period. Participants in both PLA and LCR groups were required to follow a specific resistance training program (4 d/wk, upper body/lower body split) as well as oral ingestion of either PLA or LCR (2 g/day-1) for a 9-wk period, while the CON group did not receive any intervention. Data were analyzed by GLM and presented as mean (SD) or change (95% CI).
Results
We observed a significant increase in bench press lifting volume (LV) at wk-6 (139 kg, 95% CI 49.1, 230) and wk-9 (238 kg, 95% CI, 132, 343) for LCR. There was a significant improvement in leg press LV at wk-6 (1,483 kg, 95% CI, 543, 2,422) and wk-9 (2,683 kg, 95% CI, 1,568, 3,797) for LCR. The percent change from baseline in LV bench press, leg press, and total strength for LCR was 27.5%, 30.2%, and 15.0% respectively. The significant increase in Wingate mean power (63.4 W, 95% CI 30.5, 96.3) and peak power (239 W/kg, 95% CI 104, 374) was seen at wk-9 for LCR. The percent change from baseline in Wingate mean power and peak power for LCR was 12.8% and 14.4% respectively. The significant BL reduction at wk-9 in 3-min post-exercise (-1.84 mmol/l, 95% CI -2.95, -0.73), 15-min post-exercise (-1.60 mmol/l, 95% CI -2.63, -0.57), and 30-min post-exercise (-0.64 mmol/l, 95% CI, -1.07, -0.21) was observed only in LCR. The percent change from baseline in BL at minutes three, fifteen, and thirty post-exercise for LCR was -17.2%, -14.8%, and -13.6% respectively.
Conclusion
Our results indicate that LCR supplementation at the dose of 2 g/day-1 increases muscle strength, improves anaerobic performance, and attenuates the blood lactate response to resistance training.
Effects of chronic L-carnitine supplementation on exercise-induced oxidative stress markers in resistance-trained males
Majid S Koozehchian1, Amin Daneshfar2, Mozhgan Hassanzadeh3, Maryam Kaveh4, Ebrahim Fallah2, Conrad P Earnest FACSM1,5, Gholamali Owlia6, Mike Greenwood FACSM1, Richard B Kreider FACSM1
1Exercise & Sport Nutrition Lab, Human Clinical Research Facility, Department of Health & Kinesiology, Texas A&M University, College Station, TX 77843 USA
2Kinesiology, Tarbiat Modares University, Tehran, 14115-111 Iran
3Department of Kinesiology, Azad University, Central Branch, Tehran, Iran
4Department of Pharmaceutical Practice, Karnataka College of Pharmacy, Bangalore, India
5Nutrabolt, Bryan, TX 77807, USA
6Department of Health & Kinesiology, Texas Southern University, Houston, TX 77004 USA
Corresponding author: [email protected]
Background
The purpose of this study was to examine the long-term effects of ingesting L-Carnitine supplement on exercise-induced oxidative stress markers.
Method
In a randomized, placebo-controlled, double-blind design, 35 male participants (age = 25 ± 2 y; stature = 171 ± 6 cm; body mass = 79.8 ± 8.9 kg; percent body fat = 16.1 ± 5.53%; Control [CON] n = 12, Placebo [PLA] n = 11, L-carnitine [LCR] n = 12) participated in the study. Oxidative stress markers including total antioxidant capacity (TAC), malondialdehyde (MDA), glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase (CAT), interleukin-6 (IL-6), and tumor necrosis alpha (TNF-α) which were measured at baseline and at weeks 3, 6, and 9. All participants were asked to maintain their normal dietary intake during the study period. Participants in both PLA and LCR groups were required to follow a specific resistance training program (4 d/wk, upper body/lower body split) as well as oral ingestion of either PLA or LCR (2 g/day-1) for a 9-wk period, while the CON group did not receive any intervention. Data were analyzed by GLM and presented as mean (SD) or change (95% CI).
Results
We observed a significant increase in TAC at wk-9 in LCR (0.18 mmol/L, 95% CI, 0.07, 0.28). A significant increase was seen in serum GPx at wk-9 in LCR (1.75 U/ml, 95% CI, 0.61, 2.90). There was a significant decrease in serum IL-6 at wk-9 in LCR (-0.53 pg/mL, 95% CI, -1.00, -0.06). The percent change from baseline in serum TAC was increased only in LCR (11.5%), but not in PLA (-0.02%), or CON (-1.94%). There was a significant decrease in percent change from baseline in serum MDA only in LCR (-31.1%), but not in CON (14.5%). A significant increase was seen in serum GPx only in LCR (17.4%), nut not in PLA (-3.26).
Conclusion
Our results indicate that LCR supplementation at the dose of 2 g/day-1 improves total antioxidant capacity, while it attenuates exercise-induced oxidative stress makers in resistance-trained males.