Gastric emptying, intestinal absorption of electrolytes and exercise performance in electrolyte-supplemented horses (original) (raw)
Related papers
Plasma and sweat electrolyte concentrations in the horse during long distance exercise
Equine Veterinary Journal, 1980
SummaryBlood samples were taken from 20 horses competing in a 100 km endurance ride and plasma concentrations of sodium, potassium, chloride, bicarbonate and protein measured. Measurements were performed on samples taken before the ride (pre‐ride), at the mid point and end of the ride and after a 30 min recovery period (post‐ride). Sweat samples were collected from 6 horses competing in the endurance ride and 14 horses competing in a 3‐day event competition and sweat concentrations of sodium, potassium and chloride measured. There were substantial decreases in plasma electrolyte concentrations, which were greater than previously reported. Decreases from pre to post ride samples of 5 mmol/1 of sodium, 1.2 mmol/1 of potassium and 16 mmol/1 of chloride were found. These losses appeared to be related directly to sweat electrolyte concentrations, where potassium and chloride had relatively greater concentrations than in plasma.RésuméDes échantillons de sang ont été prélevés sur 20 chevau...
European Journal of Applied Physiology, 1998
This study investigated the eects on running economy (RE) of ingesting either no¯uid or an electrolyte solution with or without 6% carbohydrate (counterbalanced design) during 60-min running bouts at 80% maximal oxygen consumption ( O 2max ). Tests were undertaken in either a thermoneutral (22±23°C; 56±62% relative humidity, RH) or a hot and humid natural environment (Singapore: 25±35°C; 66±77% RH). The subjects were 15 young adult male Singaporeans [ O 2max 55.5 (4.4 SD) ml kg A1 min A1 ]. The RE was measured at 3 m s A1 [65 (6)% O 2max ] before (RE1) and after each prolonged run (RE2). Fluids were administered every 2 min, at an individual rate determined from prior tests, to maintain body mass (group mean 17.4 ml min A1 ). The O 2 during RE2 was higher (P < 0.05) than that during the RE1 test for all treatments, with no dierences between treatments (ANOVA). The mean increase in O 2 from RE1 to RE2 ranged from 3.4 to 4.7 ml kg A1 min A1 across treatments. In conclusion, the deterioration in RE at 3 m s A1 (65% O 2max ) after 60 min of running at 80% O 2max appears to occur independently of whether¯uid is ingested and regardless of whether the¯uid contains carbohydrates or electrolytes, in both a thermoneutral and in a hot, humid environment.
Medicine & Science in Sports & Exercise, 2020
Background: There is limited information on the effects of sports drinks on cognitive function after exercise in the heat. We aimed to investigate the effects of ingesting a commercially available carbohydrate-electrolyte (CHO) solution on cognitive performance following exercise-induced hyperthermia. Methods: Twelve participants completed three practices of cognitive tests, one full familiarisation and two experimental trials in an environmental chamber (dry bulb temperature: 30.2 ± 0.3°C, relative humidity: 70 ± 3%). The experimental trials consisted of five cognitive tests (symbol digit matching, search and memory, digit span, choice reaction time and psychomotor vigilance test) performed before and after a 75-min run on a treadmill at 70% VO 2 max. One ml/kg body mass of a 6.8% CHO solution or placebo was consumed at the start, every 15 min during exercise and between cognitive tests after exercise. Core temperature, heart rate, blood glucose concentrations, subjective ratings and cognitive performance were assessed (symbol digit matching, search and memory, digit span, choice reaction time and psychomotor vigilance). Results: Participants were hyperthermic at the end of the run (placebo: 39.5 ± 0.4°C, CHO: 39.6 ± 0.5°C; Mean ± SD; p = 0.37). The change in blood glucose was higher with CHO ingestion (1.6, 0.7 to 4.5 mmol/L) (median, range) than with placebo ingestion (0.9,-0.1 to 4.7 mmol/L; p < 0.05). CHO ingestion reduced the maximum span of digits memorized, in contrast to an increase in maximum span with placebo ingestion (p < 0.05). CHO solution had no effect on other cognitive tests (p > 0.05). Conclusions: These results suggest that CHO solution ingestion may impair short-term memory following exertional heat stress.
European Journal of Applied Physiology
Purpose To reduce the need for invasive and expensive measures of human biomarkers, sweat is becoming increasingly popular in use as an alternative to blood. Therefore, the (in)dependency of blood and sweat composition has to be explored. Methods In an environmental chamber (33 °C, 65% relative humidity; RH), 12 participants completed three subsequent 20-min cycling stages to elicit three different local sweat rates (LSR) while aiming to limit changes in blood composition: at 60% of their maximum heart rate (HRmax), 70% HRmax and 80% HRmax, with 5 min of seated-rest in between. Sweat was collected from the arm and back during each stage and post-exercise. Blood was drawn from a superficial antecubital vein in the middle of each stage. Concentrations of sodium, chloride, potassium, ammonia, lactate and glucose were determined in blood plasma and sweat. Results With increasing exercise intensity, LSR, sweat sodium, chloride and glucose concentrations increased (P ≤ 0.026), while simul...
Fluid and electrolyte supplementation for exercise heat stress
The American Journal of Clinical Nutrition
During exercise in the heat, sweat output often exceeds water intake, resulting in a body water deficit (hypohydration) and electrolyte losses. Because daily water losses can be substantial, persons need to emphasize drinking during exercise as well as at meals. For persons consuming a normal diet, electrolyte supplementation is not warranted except perhaps during the first few days of heat exposure. Aerobic exercise is likely to be adversely affected by heat stress and hypohydration; the warmer the climate the greater the potential for performance decrements. Hypohydration increases heat storage and reduces a person's ability to tolerate heat strain. The increased heat storage is mediated by a lower sweating rate (evaporative heat loss) and reduced skin blood flow (dry heat loss) for a given core temperature. Heat-acclimated persons need to pay particular attention to fluid replacement because heat acclimation increases sweat losses, and hypohydration negates the thermoregulatory advantages conferred by acclimation. It has been suggested that hyperhydration (increased total body water) may reduce physiologic strain during exercise heat stress, but data supporting that notion are not robust. Research is recommended for 3 populations with fluid and electrolyte balance problems: older adults, cystic fibrosis patients, and persons with spinal cord injuries.
Antioxidants, 2020
Low-osmolality carbohydrate–electrolyte solution (LCS) ingestion can replace losses from exercise-induced dehydration, but the benefits of LCS ingestion strategy after exhaustive endurance exercise (EEE) remain unknown. The present study evaluated the effects of LCS ingestion on dehydration, oxidative stress, renal function, and aerobic capacity after EEE. In our study with its double-blind, crossover, counterbalanced design, 12 healthy male participants were asked to consume LCS (150 mL four times per hour) or placebo (water) 1 h before and 1 h after EEE. All participants completed a graded exercise test to exhaustion on a treadmill for the determination of maximal oxygen consumption ( V ˙ O 2 max ), applied to further intensity calibration, and then completed the EEE test. The average heart rate, maximal heart rate, running time to exhaustion, and peak oxygen uptake (VO2peak) were recorded during the exercise period. The participants’ body weight was recorded at different time poi...
Changes in arterial, mixed venous and intraerythrocytic ion concentrations during prolonged exercise
Equine Veterinary Journal, 2010
Reasons for performing study: Prolonged equine exercise can cause hypochloraemic alkalosis and hypokalaemia secondary to the loss of hypertonic sweat. Movement of ions in and out of erythrocytes during exercise may help regulate acid-base balance and changes in plasma ion concentrations. The extent to which this happens during prolonged equine exercise has not been reported. Objectives: To measure changes in blood gases and major plasma and intraerythrocytic (iRBC) ion concentrations of horses undergoing prolonged submaximal exercise. Methods: Six horses were trotted at~30% V O2max on a treadmill for 105 min. Arterial (a) and mixed venous (v) blood samples were collected every 15 min, and pre-and post exercise. Blood gases and plasma (pl) concentrations of sodium, potassium, chloride and protein were measured and their iRBC concentrations calculated and compared (P<0.05
Sports Medicine, 2015
Intramuscular acidosis is a contributing factor to fatigue during high-intensity exercise. Many nutritional strategies aiming to increase intra-and extracellular buffering capacity have been investigated. Among these, supplementation of beta-alanine (*3-6.4 g/day for 4 weeks or longer), the rate-limiting factor to the intramuscular synthesis of carnosine (i.e. an intracellular buffer), has been shown to result in positive effects on exercise performance in which acidosis is a contributing factor to fatigue. Furthermore, sodium bicarbonate, sodium citrate and sodium/calcium lactate supplementation have been employed in an attempt to increase the extracellular buffering capacity. Although all attempts have increased blood bicarbonate concentrations, evidence indicates that sodium bicarbonate (0.3 g/kg body mass) is the most effective in improving high-intensity exercise performance. The evidence supporting the ergogenic effects of sodium citrate and lactate remain weak. These nutritional strategies are not without side effects, as gastrointestinal distress is often associated with the effective doses of sodium bicarbonate, sodium citrate and calcium lactate. Similarly, paresthesia (i.e. tingling sensation of the skin) is currently the only known side effect associated with beta-alanine supplementation, and it is caused by the acute elevation in plasma beta-alanine concentration after a single dose of beta-alanine. Finally, the co-supplementation of beta-alanine and sodium bicarbonate may result in additive ergogenic gains during high-intensity exercise, although studies are required to investigate this combination in a wide range of sports.
2013
Heavy sweating after prolonged exercise can cause body fluid losses and alteration of the body function. The purpose of this study was to identify whether electrolytes supplementation promoting rehydration following exercise induced dehydration in male rats. Animals assigned into four equal groups. GroupI served as control, GroupII animals practiced exercise through training program on treadmill,GroupIII animals exercised on treadmill then supplemented by Rehydran-n content dissolved in water. GroupIV animals exercised on treadmill and then supplemented by Rehydran-n content and (Magnesium + Calcium) citrate dissolved in water. After 6 weeks animals were slaughtered and the harvested serum was used to estimate creatine phosphokinase (CPK), lactate dehydrogenase (LDH) enzymes, kidney function (urea and creatinine), Na , K , Cl , Mg , Ca , P ions and aldosterone. Also heart and kidney tissues were dissected out for + + - 2+ 2+ histopathological examination. The results revealed an inc...
2010
Early postexercise muscle glycogen recovery is enhanced with a carbohydrate-protein supplement. present study, we tested the hypothesis that a carbohydrate-protein (CHO-Pro) supplement would be more effective in the replenishment of muscle glycogen after exercise compared with a carbohydrate supplement of equal carbohydrate content (LCHO) or caloric equivalency (HCHO). After 2.5 Ϯ 0.1 h of intense cycling to deplete the muscle glycogen stores, subjects (n ϭ 7) received, using a rank-ordered design, a CHO-Pro (80 g CHO, 28 g Pro, 6 g fat), LCHO (80 g CHO, 6 g fat), or HCHO (108 g CHO, 6 g fat) supplement immediately after exercise (10 min) and 2 h postexercise. Before exercise and during 4 h of recovery, muscle glycogen of the vastus lateralis was determined periodically by nuclear magnetic resonance spectroscopy. Exercise significantly reduced the muscle glycogen stores (final concentrations: 40.9 Ϯ 5.9 mmol/l CHO-Pro, 41.9 Ϯ 5.7 mmol/l HCHO, 40.7 Ϯ 5.0 mmol/l LCHO). After 240 min of recovery, muscle glycogen was significantly greater for the CHO-Pro treatment (88.8 Ϯ 4.4 mmol/l) when compared with the LCHO (70.0 Ϯ 4.0 mmol/l; P ϭ 0.004) and HCHO (75.5 Ϯ 2.8 mmol/l; P ϭ 0.013) treatments. Glycogen storage did not differ significantly between the LCHO and HCHO treatments. There were no significant differences in the plasma insulin responses among treatments, although plasma glucose was significantly lower during the CHO-Pro treatment. These results suggest that a CHO-Pro supplement is more effective for the rapid replenishment of muscle glycogen after exercise than a CHO supplement of equal CHO or caloric content. catecholamines; glucose; lactate; insulin; nuclear magnetic resonance spectroscopy MUSCLE GLYCOGEN IS an essential fuel source for moderate-to high-intensity exercise. Once depleted, the capacity to perform at these exercise intensities is lost or severely limited . Therefore, the faster the muscle glycogen stores can be replenished after exercise the faster the recovery process and theoretically