Sucrose ingestion following exercise: selected cardiovascular, hormonal, renal, and metabolic effects.

Abstract

Carbohydrates, frequently consumed following exercise for glycogen resynthesis, have been shown to have other systemic effects in resting men. We examined the effects of postexercise sucrose (a disaccharide carbohydrate) ingestion on the renal, cardiovascular, and sympathetic nervous systems. Eight men consumed 1 l of water (W) or 1 l of a 200 g sucrose solution (S) following 1 hour of bicycle exercise at 70% heart rate reserve. Measurements were made during 2 hours of recovery. Heart rate and systolic blood pressure were elevated following S as compared to W (p < 0.009, p < 0.04, respectively). Diastolic blood pressure was lower after S (p < 0.04) and mean blood pressure did not differ between beverages. Plasma and urinary catecholamines decreased similarly after exercise regardless of treatment. After S insulin (p = 0.0019) and glucose (p = 0.0036) were increased but serum aldosterone (p = 0.0083) and potassium (p = 0.0285) responses were lower. No differences were observed for plasma renin activity. Urine volume and kaliuresis were less after S (p = 0.03, p = 0.03). A 24% increase in metabolic rate (p = 0.002) and increased respiratory exchange ratio (p = 0.02) after S were observed. Systemic effects of sucrose ingestion following exercise include cardiovascular, renal, endocrine, and metabolic changes.

Systemic effects of ingesting varying amounts of a commercial carbohydrate beverage postexercise.

“…Carbohydrate ingestion may have attenuated decreases seen in postexercise SBP by virtue of increased splanchnic perfusion and subsequent increases in HR and CO. Elevation in blood pressure and HR following carbo hydrate have been associated with increased sympathetic nervous system activity at rest [20,21]. However, in a previous study on normotensive men, we found no differ ence in plasma catecholamine levels when sucrose was consumed as compared to water ingestion postexercise [13]. Consequently, we did not measure catecholamines in the studies reported here.…”

“…Ingestion of a beverage containing 200 g of glucose polymer/fructose dissolved in 1 L of water, or approxi mately 2.7 g/kg body weight CHO, resulted in systemic changes similar to those reported following ingestion of a beverage containing 200 g of sucrose [13]. In general, the effects were less pronounced when the beverage contained 1.5 g/kg body weight of the commercial carbohydrate powder.…”

“…SBP was elevated as compared to W ingestion only at the higher level of CHO consumption (Study A). Previous studies have shown increases in HR and SBP following consump tion of 1 g/kg of various sugars at rest [10], and when 200 g of sucrose was consumed postexercise [13]. It appears, therefore, that glucose polymer/fructose must be provided in amounts >1.5 g/kg postexercise to elevate SBP over simple water ingestion following exercise.…”

“…Previously, we examined effects of postexercise sucrose ingestion on cardiovascular and renal parameters in normotensive men [13]. Sucrose ingestion attenuated the de crease in SBP typically observed during exercise recovery [14] compared to W. No significant effect of sucrose on catecholamines was found.…”

“…Although carbohydrate ingestion has in some studies been associated with a rise in catecholamines [11,12], other studies [9,13] have failed to show consistent increases in epinephrine or norepinephrine during carbohydrate-induced hypertension. Preuss et al [9] reported carbohydrate-induced SBP elevations in rats, without concomitant increases in catecholamine lev els.…”