Effects of Carnitine Coingested Caffeine on Carnitine Metabolism and Endurance Capacity in Athletes.

Abstract

SummaryThe purpose of this study was to examine whether caffeine (CAF), carnitine (CAR), or CAP+CAR mixture administration affects exercise endurance time via carnitine metabolism. Water (CON), CAF, CAR, or CAF+CAR mixture was administered to five male rugby athletes participating in this study by a randomized double-blind fashion who were made to ride a cycle ergometer for exercise. The CAF effect on exercise endurance time was small, but the CAR trial significantly increased the exercise endurance time compared with CON trial; a further CAP +CAR mixture trial had greater effects on the exercise endurance time than those of a CON, CAF, or CAR trial. A CAR or CAF+CAR mixed trial increased uri nary nonesterified carnitine (NEC) and total carnitine (TCAR), but no changes were ob served in acid-soluble acylcarnitine (ASAC) and acid-insoluble acylcarnitine (AIAC) excre tion. A CAR or CAF+CAR mixed trial resulted in higher levels of plasma NEC, ASAC, and TCAR fractions than the CON and CAF trials did on exhaustion time. Total cholesterol, triglyceride, and free fatty acid in blood were significantly increased at exhaustion time, but they were not affected in the CAF or the CAR trial. These results suggest that carnitine in gestion could promote fat oxidation, resulting in higher endurance performance in athletes, and especially these ergogenic effects of carnitine coingested with caffeine may be greater than those of carnitine alone.

Effect of Various Carbohydrate-Electrolyte Fluids on Cycling Performance and Maximal Voluntary Contraction

“…Carnitine may (Cha et al, 2001) or may not (Broad, Maughan, & Galloway, 2005;Colombani et al, 1996) increase aerobic performance. Ingestion of carnitine can increase whole-body glucose uptake (Mingrone et al, 1999), but the few studies observing increases in performance with carnitine (Cha et al) used concentrations much greater (15 g) than those used in the current study (~90 mg).…”

Does Caffeine Added to Carbohydrate Provide Additional Ergogenic Benefit for Endurance?

“…Thirty-three peer-reviewed research articles met the inclusion criteria (Alves et al, 1995;Bell, Jacobs, & Zamecnik, 1998;Berglund & Hemmingsson, 1982;Bridge & Jones, 2006;Butts & Crowell, 1985;Cadarette, Levine, Berube, Posner, & Evans, 1983;Cha et al, 2001;Cohen et al, 1996;Collomp et al, 2002;Conway, Orr, & Stannard, 2003;Costill et al, 1978;Denadai & Denadai, 1998;French et al, 1991;Fulco et al, 1994;Graham, Hibbert, & Sathasivam, 1998;Graham & Spriet, 1991;Greer, Hudson, Ross, & Graham, 2001;Ivy et al, 1979;Jenkins, Trilk, Singhal, O'Conner, & Cureton, 2008;Lindinger, Graham, & Spriet, 1993;MacIntosh & Wright, 1995;McLellan, Bell, & Kamimori, 2004;McNaughton et al, 2008;Norager, Jensen, Madsen, & Laurberg, 2005;Pasman et al, 1995;Powers, Byrd, Tulley, & Callendar, 1983;Sasaki et al, 1987;Slivka et al, 2008;Spriet et al, 1992;Trice & Haymes, 1995;Van Soeren & Graham, 1998; Table 3). Three research articles Berglund & Hemmingsson, 1982;Butts & Crowell, 1985) reported Note.…”

Antioxidant and oligonutrient status, distribution of amino acids, muscle damage, inflammation, and evaluation of renal function in elite rugby players

“…Its role in intense exercise is unclear and debated. It seems that a supplement of carnitine helps the athlete to use fat as substratum of energy in a more effective way (46) . Carnitine would also allow a delay in the feeling of tiredness during a long and strong training (47) .…”