| Study |
Population |
Daily carnitine dose |
Treatment duration |
Endpoints |
Carnitine effects |
|
| Marconi et al, 1985 (25) |
6 competitive walkers |
4 g orally |
2 wk |
 O2max, lactate, RQ |
Increase in O2max, no change in RQ at fixed workload |
| Greig et al, 1987 (32) |
9 untrained subjects |
2 g orally |
14 d |
Maximal exercise, lactate |
No change in O2max or lactate |
| Greig et al, 1987 (32) |
10 untrained subjects |
2 g orally |
28 d |
Maximal exercise, lactate |
No change in O2max or lactate |
| Dragan et al, 1987 (43) |
40 elite athletes |
3 g orally |
21 d |
O2max |
Increase in O2max |
| Oyono-Enguelle et al, 1988 (36) |
10 untrained males |
2 g orally |
28 d |
O2, CO2, RQ, lactate, workload exercise |
No effect of carnitine plasma glucose at fixed |
| Soop et al, 1988 (37) |
7 moderately trained males |
5 g orally |
5 d |
FFA turnover during exercise, O2 at fixed workload exercise |
No effect of carnitine |
| Gorostiaga et al, 1989 (24) |
10 trained athletes |
2 g orally |
28 d |
RQ, O2, heart rate, lactate, plasma glucose at fixed workload |
Decrease in RQ; no other significant changes |
| Siliprandi et al, 1990 (41) |
10 moderately trained males |
2 g orally |
1 dose 1 h before exam |
Plasma lactate |
Postexercise lactate reduced by carnitine |
| Vecchiet et al, 1990 (42) |
10 moderately trained males |
2 g orally |
1 dose 1 h before exercise |
O2max, plasma lactate |
O2max increased and lactate decreased |
| Wyss et al, 1990 (33) |
7 healthy males |
3 g orally |
7 d |
O2max RQ |
No effect of carnitine under normal conditions |
| Decombaz et al, 1993 (38) |
9 healthy males |
3 g orally |
7 d |
Fat oxidation, RQ, perceived exercise after glycogen depletion |
No effect of carnitine exertion, lactate, heart rate during |
| Natali et al, 1993 (44) |
12 active males |
3 g intravenously |
1 dose 40 min before exercise |
O2, CO2, substrate oxidation during and after exercise |
No changes during exercise, but increased fatty acid oxidation during recovery with carnitine |
| Trappe et al, 1994 (34) |
20 male athletes |
2 g BID orally |
7 d |
Swimming performance, lactate concentration |
No effect of carnitine |
| Brass et al, 1994 (15) |
14 healthy males |
92.5 mol/kg or 18.5 mol/kg intravenously |
1 dose at beginning of exercise |
RQ, O2 lactate, muscle glycogen at fixed workload |
No effect of carnitine |
| Vukovich et al, 1994 (39) |
8 healthy males |
6 g orally |
7–14 d |
RQ, FFA glucose utilization, O2 during fixed workload exercise |
No effect of carnitine |
| Barnett et al, 1994 (40) |
8 healthy males |
4 g orally |
14 d |
Lactate during exercise, muscle carnitine content |
No effect of carnitine |
| Colombani et al, 1996 (35) |
7 male athletes |
4 g orally |
Day of event |
Marathon time and postrace lactate |
No effect of carnitine |
|
| 1BID, twice daily; FFA, free fatty acids; CO2, carbon dioxide production; O2, oxygen consumption; O2 max, maximal oxygen consumption during exercise; RQ, respiratory quotient (CO2 /O2). |
