EFFECTS OF DICHLOROACETATE ON EXERCISE PERFORMANCE IN HEALTHY-VOLUNTEERS

Dichloroacetate (DCA), a stimulator of the pyruvate dehydrogenase comp lex, decreases lactate levels and peripheral resistance and increases cardiac output. This study was performed to examine the effects of DCA on exercise performance in humans. Eight healthy male volunteers (age 20-28 years) were tested by bicycle spiro-ergometry using a microproc essor-controlled gas analysis system after infusion of DCA (50 mg/kg b ody weight) or saline. Prior infusion of DCA significantly reduced the increase of lactate levels during exercise when compared with infusio n of saline (1.40 +/- 0.21 vs 2.10 +/- 0.09 mmol.l-1 at 50 % of the ex pected maximal working capacity, P < 0.05; 8.53 +/- 0.45 vs 9.92 +/- 0 .59 mmol.l-1 at maximal working capacity, P < 0.05). Oxygen uptake inc reased significantly after DCA when compared with saline from 7.5 +/- 0.4 vs 7.4 +/- 0.5 to 27.2 +/- 1.5 vs 23.7 +/- 1.7 (P < 0.05) at anaer obic threshold and to 35.6 +/- 1.7 vs 30.5 +/- 1.0 ml.kg-1 min-1 (P < 0.05) at maximal exercise capacity. Following DCA infusion the workloa d at which the anaerobic threshold was reached was significantly highe r (160 +/- 7 vs 120 +/- 5 W, P < 0.05) and the maximal working capacit y was significantly increased (230 +/- 9 vs 209 +/- 8 W, P < 0.05). In summary, DCA reduced the increase of lactate levels during exercise a nd increased oxygen uptake at the anaerobic threshold and at maximal w orking capacity, which was significantly increased. These results warr ant further studies on a potential therapeutic application of DCA in p atients with reduced exercise capacity.