The effects of high intensity exercise on the plasma concentration of lactate, potassium and other electrolytes

Abstract

Summary To study the effect of short term high intensity exercise on plasma lactate, potassium, sodium and chloride concentrations, five Thoroughbred horses were galloped on a treadmill at a 5° incline. Following a standardised warm‐up period, they were galloped at 8, 10, or 12 metres/sec for 2 mins. One horse also galloped at 14 metres/sec for 1.5 mins. Sequential arterial and/or venous blood samples were collected during exercise and recovery. At 12 metres/sec, the effect of different recovery modes, ie, standing, walking or trotting, on the electrolytes was also examined. There was a progressive rise in plasma potassium concentration during galloping, with peak values occurring at the end of the exercise bout. In some cases, values above 10 mmol/litre were recorded at the highest workloads. Plasma lactate concentrations peaked during early recovery, with values up to 32 mmol/litre. A high correlation existed between peak potassium and lactate concentrations (venous r=0.923, and arterial r=0.989). Following exercise there was a rapid return to baseline plasma potassium concentrations, but by 12 mins recovery there was still an elevated lactate concentration, the extent depending on the intensity of the exercise bout and the recovery mode. There was a small rise in plasma sodium but no significant change in plasma chloride concentrations during exercise. However, when adjusted for the decrease in plasma volume, as determined from total plasma protein concentration, there was a decrease in circulating amounts of both electrolytes.

Perfil hematológico de equinos submetidos à prova de Team Penning

“…Neste estudo, observou-se aumento do volume globular após a prática de atividade física, fato também relatado por Snow et al (1983a), Harris & Snow (1988 (2000), Gómez et al (2004), Orozco (2007) e Ferraz et al (2009. No presente estudo, isto também ocorreu, possivelmente, com o intuito de aumentar a capacidade de oxigenação do sangue como resposta fisiológica ao exercício.…”

Evaluation of the Usefulness of the Portable Device Lactate Pro for Measurement of Lactate Concentrations in Equine Whole Blood

“…7 In horses, plasma lactate concentrations during or shortly after maximal treadmill exercise may rise to even 32 mmol/liter, but this is very rare under field circumstances. 2 Obviously, such values are not within the range provided by the manufacturer and are possibly too high for reliable measurement using the Lactate Pro. Whether this instrument can be used to measure lactate concentrations in high-intensity exercise remains to be determined, using blood samples with higher lactate concentrations.…”

Effects of the Daily Administration of a Rehydrating Supplement to Trotter Horses

“…The largest losses of fluids and electrolytes are observed in endurance races, but they are also considerable in track races, especially at high temperatures, when the race is preceded by a long warm-up, and when horses have not rested sufficiently after a long transfer trip [9]. A rapid, albeit transient, d e c r e a s e i n i n t r a c e l l u l a r K + a n d i n c r e a s e i n extracellular K + concentrations may contribute to fatigue onset during high-intensity exercise [17].…”