The Effects of Ingesting Polylactate or Glucose Polymer Drinks during Prolonged Exercise

Abstract

Five trained, fasted male cyclists rode a cycle ergometer three times at 50% of,max for 180 min. Using a balanced order, double-blind procedure,subjects were given either a solution containing polylactate (PL: 80% polylactate, 20% sodium lactate, in 7% solution with water), glucose polymer (GP: multidextrin in 7% solution with water), or control (C: water sweetened with aspartame) 5 min before exercise and at 20-min intervals during exercise. Venous blood samples were taken at rest and at 20-min intervals during exercise. In general, PL and GP rendered similar results except that pH and bicarbonate () were higher in PL. There were no differences between treatments in perceived exertion, sodium, potassium, chloride, lactate, heart rate, oxygen consumption, rectal temperature, or selected skin temperatures. These data show that polylactate may help maintain blood glucose and enhance blood buffering capacity during prolonged exercise and could be a useful component in an athletic fluid replacement beverage.

Adding Polylactate to a Glucose Polymer Solution Does Not Improve Endurance

“…Originally, we wanted to compare a 7 % PL solution to a 7 % GP solution, but we were unable to use PL in concentrations 2.5 % because the supplement, as supplied by the manufacturer and under our experimental conditions, produced severe gastro-intestinal distress within 1-3 hours after the start of a trial. Fahey et al (14) also found that PL had a similar effect on most of their subjects (personal communication). Their test mixture, however, contained 5.6 grams of PL and 1.4 grams of sodium lactate per 100 ml of water.…”

“…It is doubtful that such an effect would prolong aerobic endurance, but it could improve the ability to perform intense, short duration exercise, such as been shown for bicarbonate induced alkalosis (11,16,18,29). Fahey et al (14) found that a 7% PL solution significantly increased blood pH, a finding which suggests that PL may have similar performance effects as bicarbonate. We were unable, however, to corroborate Fahey's finding, as the GP/PL mixture and the GP solution had similar, non-significant effects on blood pH.…”

“…Given that Fahey et a!. (14) administered more PL per hour than we did, and the large dose (0.3 g per kg of body wt bolus) of the more potent Table 3 Changes in free fatty acid, glycerol, glucose, insulin, lactate and pH during the first 180 minutes of exercise at 70 % of maximum aerobic power.…”

“…This carbohydrate supplement is called Poly L-LactateTM (PL). The only study that has examined PUs potential as an exogenous carbohydrate source during exercise in man was conducted by Fahey et al (14). They found that a 7% PL solution was as effective at maintaining plasma glucose levels as a 7 % GP solution during 3 hours of cycling at 50 % of VO2max, which suggests the product has the potential to prolong exercise endurance when compared to water, The purpose of our study was, therefore, to more fully assess PL's usefulness as an exogenous carbohydrate source by determining if the addition of PL to a GP solution affects time to exhaustion during a cycling trial at 70% of VO2max.…”

Efeitos da suplementação crônica de lactato de cálcio e bicarbonato de sódio sobre desempenho físico em exercício intermitente de alta intensidade

“…Contudo, apenas um estudo apresentou resultados positivos, com uma grande melhora de 25% no desempenho aeróbio (AZEVEDO et al, 2007). No entanto, como há aumento dos níveis de pH (FAHEY et al, 1991;MORRIS, et al, 2011;PAINELLI et al, 2014) e bicarbonato (FAHEY et al, 1991;PAINELLI et al, 2014) (MCNAUGHTON, et al, 1999), pois pode promover um incremento maior no bicarbonato sanguíneo com o maior período de suplementação, mas esse protocolo ainda precisa ser explorado. Os dados estão apresentados como média ± desvio-padrão.…”