EFFECTS OF 2-CHLOROPROPIONATE ON VENOUS PLASMA LACTATE CONCENTRATION AND ANAEROBIC POWER DURING PERIODS OF INCREMENTAL INTENSIVE EXERCISE IN HUMANS

We investigated the effects of a stimulation of pyruvate dehydrogenase (PDH) activity induced by 2-chloropropionate (2-CP) on venous plasma lactate concentration and peak anaerobic power (W-an,W-peak) during pe riods (6 s) of incremental intense exercise, i.e. a force-velocity (F- v) test known to induce a marked accumulation of lactate in the blood. The F-v test was performed twice by six subjects according to a doubl e-blind randomized crossover protocol: once with placebo and once with 2-CP (43 mg . kg(-1) body mass). Blood samples were taken at ingestio n of the drug, at 10, 20, and 40 min into the pretest period, at the e nd of each period of intense exercise, at the end of each 5-min recove ry period, and after completion of the F-v test at 5, 10, 15, and 30 m in. During the F-v test, venous plasma lactate concentrations with bot h placebo and 2-CP increased significantly when measured at the end of each period of intense exercise (F = 33.5, P < 0.001), and each 5-min recovery period (F = 24.6, P < 0.001). Venous plasma lactate concentr ations were significantly lower with 2-CP at the end of each recovery period (P < 0.01), especially for high braking forces, i.e. 8 kg (P < 0.05), 9 kg (P < 0.02), and maximal braking force (P < 0.05). After co mpletion of the F-v test, venous plasma lactate concentrations were al so significantly lower with 2-CP (P < 0.001). The percentage of lactat e decrease between 5- and 30-min recovery was significantly higher wit h 2-CP than with the placebo [59 (SEM 4)% vs 44.6 (SEM 5.5)%, P < 0.05 ]. Furthermore, W-an,W-peak was significantly higher with 2-CP than wi th the placebo [1016 (SEM 60) W vs 957 (SEM 55) W, P < 0.05]. In concl usion, PDH activation by 2-CP attenuated the increase in venous plasma lactate concentration during the F-v test. Ingestion of 2-CP led to a n increased W-an,W-peak.