Effects of fructose-1,6-diphosphate on heart rate, ventilation, oxygen consumption and endurance performance.

A controlled study was carried out in 12 healthy male volunteers to evaluate the effects of fructose-1,6-diphosphate (FDP) on cardiac and respiratory parameters and work capacity during maximal muscular exercise on a cycloergometer. Each subject was studied in 3 sessions, separated by at least 36 hours. Workload started at 50 watts with stepwise increases, consisting of 25 watts every 3 minutes, up to muscular exhaustion or until the predicted maximum heart rate was attained. The first session, with no treatment, served as the control test; in the other two sessions, each subject received, prior to exercising, a single intravenous dose of either 7.5 g dextrose or 15 g FDP, according to a within-subject comparative study design. In resting conditions and during the exercise, heart rate, ventilation (VE), and oxygen consumption (VO2) were monitored. At the end of each session, the total work (TW) performed and the maximum oxygen consumption (VO2 max) were computed. No difference was found between the values obtained in the control and dextrose treatment sessions. The increments in heart rate, VE and VO2 at each workload observed after FDP treatment were lower (p less than 0.01) than those in control and dextrose sessions. A 25% increase in TW associated with a 12% increase in VO2 max was observed after FDP (p less than 0.01). The data indicate that FDP is potentially capable of improving muscular performance, and several possible mechanisms of action for the observed effects are discussed.