Time course and magnitude of fluid and electrolyte shifts during recovery from high-intensity exercise in Standardbred racehorses

2005 ◽  
Vol 2 (2) ◽  
pp. 77-87 ◽  
Author(s):  
Amanda Waller ◽  
Michael I Lindinger

AbstractThe present study characterized the fluid and electrolyte shifts that occur in Standardbred racehorses during recovery from high-intensity exercise. Jugular venous blood was sampled from 13 Standardbreds in racing condition, at rest and for 2 h following a high-intensity training workout. Total body water (TBW), extracellular fluid volume (ECFV) and plasma volume (PV) were measured at rest using indicator dilution techniques (D2O, thiocyanate and Evans Blue, respectively). Changes in TBW were assessed from measures of body mass, and changes in PV and ECFV were calculated from changes in plasma protein concentration. Exercise resulted in a 26.9% decrease in PV. At 10 min of recovery TBW and ECFV were decreased by 2.2% and 16.5% respectively, while intracellular fluid volume was increased by 7.1%. There was a continued loss of fluid due to sweating throughout the recovery period such that TBW was decreased by 3.9% at 90 min of recovery. This decrease in TBW was nearly equally partitioned between the extracellular and intracellular fluid compartments. Plasma Na+ and Cl− contents were decreased at 1 min of recovery, but not different from rest by 40 min of recovery. Plasma K+ content at 1 min post exercise was not different from the pre-exercise value; however, by 5 min of recovery K+ content was significantly decreased and it remained decreased throughout the recovery period. It is concluded that there are very rapid and large fluid and electrolyte shifts between body compartments during and after high-intensity exercise, and that full recovery of these shifts requires 90–120 min.

2004 ◽  
Vol 1 (2) ◽  
pp. 131-139 ◽  
Author(s):  
Michael I Lindinger ◽  
Gloria McKeen ◽  
Gayle L Ecker

AbstractThe purpose of the present study was to determine the time course and magnitude of changes in extracellular and intracellular fluid volumes in relation to changes in total body water during prolonged submaximal exercise and recovery in horses. Seven horses were physically conditioned over a 2-month period and trained to trot on a treadmill. Total body water (TBW), extracellular fluid volume (ECFV) and plasma volume (PV) were measured at rest using indicator dilution techniques (D2O, thiocyanate and Evans Blue, respectively). Changes in TBW were assessed from measures of body mass, and changes in PV and ECFV were calculated from changes in plasma protein concentration. Horses exercised by trotting on a treadmill for 75–120 min incurred a 4.2% decrease in TBW. During exercise, the entire decrease in TBW (mean±standard error: 12.8±2.0 l at end of exercise) could be attributed to the decrease in ECFV (12.0±2.4 l at end of exercise), such that there was no change in intracellular fluid volume (ICFV; 0.9±2.4 l at end of exercise). PV decreased from 22.0±0.5 l at rest to 19.8±0.3 l at end of exercise and remained depressed (18–19 l) during the first 2 h of recovery. Recovery of fluid volumes after exercise was slow, and characterized by a further transient loss of ECFV (first 30 min of recovery) and a sustained increase in ICFV (between 0.5 and 3.5 h of recovery). Recovery of fluid volumes was complete by 13 h post exercise. It is concluded that prolonged submaximal exercise in horses favours net loss of fluid from the extracellular fluid compartment.


2005 ◽  
Vol 2 (2) ◽  
pp. 119-127 ◽  
Author(s):  
Amanda Waller ◽  
Michael I Lindinger

AbstractThe present study used the physicochemical approach to characterize the changes in acid–base status that occur in Standardbred racehorses during recovery from high-intensity exercise. Jugular venous blood was sampled from nine Standardbreds in racing condition, at rest and for 2 h following a high-intensity training workout. Plasma [H+] increased from 39.1±1.0 neq l−1 at rest to 44.8±2.7 neq l−1 at 1 min of recovery. A decreased strong ion difference ([SID]) was the primary contributor to the increased [H+] immediately at the end of exercise, while increased plasma weak ion concentration ([Atot]) was a minor contributor to the acidosis. A decreased partial pressure of carbon dioxide (PCO2) at 1 min of recovery had a slight alkalinizing effect. The decreased [SID] at 1 min of recovery was a result of a 15.1±3.1 meq l−1 increase in [lactate−], as [Na+] and [K+] were also increased by 6.5±0.7 and 1.14±0.06 meq l−1, respectively, at 1 min of recovery. It is concluded that high-intensity exercise and recovery is associated with significant changes in acid–base balance, and that full recovery of many parameters that determine acid–base status requires 60–120 min.


2018 ◽  
Vol 43 (7) ◽  
pp. 691-696 ◽  
Author(s):  
Ana Luiza Matias Correia ◽  
Filipe Dinato de Lima ◽  
Martim Bottaro ◽  
Amilton Vieira ◽  
Andrew Correa da Fonseca ◽  
...  

The purpose of this study was to investigate the effects of a single-dose of β-hydroxy-β-methylbutyrate free acid (HMB-FA) supplementation on muscle recovery after a high-intensity exercise bout. Twenty-three trained young males were randomly assigned to receive either a single-dose supplementation of 3 g of HMB-FA (n = 12; age, 22.8 ± 3.0 years) or placebo (PLA; n = 11; age, 22.9 ± 3.1 years). A muscle damage protocol was applied 60 min after supplementation, and consisted of 7 sets of 20 drop jumps from a 60-cm box with 2-min rest intervals between sets. Muscle swelling, countermovement jump (CMJ), maximal voluntary isometric torque (MVIT), and work capacity (WC) were measured before, immediately after, and 24, 48, and 72 h after the exercise protocol. Muscle swelling, CMJ, and MVIT changed similarly in both groups after the exercise protocol (p < 0.001), but returned to pre-exercise levels after 24 h in both groups. WC decreased similarly in both groups after the exercise protocol (p < 0.01). For HMB-FA, WC returned to pre-exercise level 24 h after exercise protocol. However, for PLA, WC did not return to pre-exercise level even 72 h after the exercise protocol. In summary, a single-dose of HMB-FA supplementation improved WC recovery after a high-intensity exercise bout. However, HMB-FA did not affect the time-course of muscle swelling, MVIT, and CMJ recovery.


1986 ◽  
Vol 6 (10) ◽  
pp. 434
Author(s):  
Vickie Hollingsworth ◽  
Barry Franklin ◽  
Jim Cameron ◽  
Seymour Gordon ◽  
C. Timmis Gerald

2013 ◽  
Vol 9 (2) ◽  
pp. 103-108
Author(s):  
R.J. Bloomer ◽  
T.M. Farney

Intensity of exercise can influence substrate utilization, with increasing intensity resulting in lower rates of fat oxidation and the reliance on carbohydrate as the preferred fuel. Fat oxidation (or more specifically, mobilization) can be assessed via the measurement of circulating glycerol, with most prior research focusing on aerobic exercise and measurements obtained during the actual exercise bout. The present study determined the degree of fat oxidation/mobilization by measuring plasma glyctierol concentrations during the one hour post-exercise recovery period following three difference exercise bouts. On four different days, exercise trained men (n=12; 23.7±1.1 years) either rested quietly or performed aerobic cycle exercise (60 min at 70% heart rate reserve), 60 s cycle sprints at 100% max wattage obtained during graded exercise testing (GXT) - a total of five, or 15 s cycle sprints at 200% max wattage obtained during GXT - a total of 10. Blood was collected before and at 1, 30 and 60 min post-exercise. Haematocrit and haemoglobin were measured to correct for changes in plasma volume. Glycerol was analysed in plasma and the area under the curve was calculated. Glycerol increased across time (P<0.0001) from pre-exercise (8.4±0.3 μg/dl) to 1 min (13.1±0.7 μg/dl), 30 min (11.3±0.6 μg/dl) and 60 min (9.1±0.5 μg/dl) post-exercise, with 1 min and 30 min post-exercise greater than pre-exercise and 60 min post-exercise (P<0.05). Area under the curve was greater (P=0.0004) for aerobic exercise (24.7±2.0 μg/dl/h), 60 second sprints (23.4±1.9 μg/dl/h) and 15 sec sprints (24.4±1.5 μg/dl/h), as compared to rest (15.3±0.8 μg/dl/h), with no differences noted between exercise bouts (P≯0.05). All exercise bouts increase circulating glycerol, with no differences noted between bouts. Although previous data indicate that low intensity aerobic exercise results in greater fat oxidation than high intensity exercise (when assessed during the actual exercise session), our findings suggest that high intensity exercise may result in similar fat oxidation/mobilization as compared to aerobic exercise during the acute post-exercise period.


2005 ◽  
Vol 288 (4) ◽  
pp. R799-R814 ◽  
Author(s):  
Jeroen P. H. M. van den Wijngaard ◽  
Asli Umur ◽  
Raymond T. Krediet ◽  
Michael G. Ross ◽  
Martin J. C. van Gemert

We developed a mathematical model of twin-twin transfusion syndrome (TTTS) that includes a hydropic recipient twin, adding interstitial and intracellular fluid compartments, fetal congestive cardiac failure, and the dynamics of renin-angiotensin system (RAS) mediators to our previous TTTS model. Ten differential equations for each twin, coupled by the net fetofetal transfusion of blood and blood components, i.e., colloids, osmoles, and RAS mediators, describe the development of fetal arterial and venous blood volumes, blood osmolality and colloid osmotic pressure (COP), interstitial fluid volume and COP, intracellular fluid volume, amniotic fluid volume and osmolality, and RAS mediator concentration. We included varying placental anastomoses, placental sharing, and amnionicity. The 20 differential equations were solved numerically from 0 to 40 wk with a 0.6-s time step. Consistent with clinical experience, model predictions are as follows. Unidirectional arteriovenous anastomoses and arteriovenous anastomoses inadequately compensated by oppositely directed anastomoses cause severe TTTS that includes a hydropic recipient. Adequately compensated arteriovenous anastomoses simulated TTTS without hydrops. The probability that oppositely directed anastomoses prevent onset of a hydropic recipient after TTTS onset, i.e., the largest interval between onset of TTTS and onset of hydrops in the recipient, was best for a venovenous anastomosis, closely followed by an arterioarterial and finally an oppositely directed arteriovenous anastomosis. Hydropic recipients have decreased amniotic fluid volume. Unequal placental sharing and amnionicity modify hydrops onset. In conclusion, our model simulates a sequence of events that results in a hydropic recipient twin in severe TTTS. The model may allow an assessment of the efficacy of current therapeutic interventions for TTTS cases that include a hydropic recipient twin.


2018 ◽  
Vol 13 (8) ◽  
pp. 1028-1033 ◽  
Author(s):  
Sjors Groot ◽  
Lars H.J. van de Westelaken ◽  
Dionne A. Noordhof ◽  
Koen Levels ◽  
Jos J. de Koning

Background: Research has shown that gross efficiency (GE) declines during high-intensity exercise, but the time course of recovery of GE after high-intensity exercise has not yet been investigated. Purpose: To determine the time course of the recovery of GE after time trials (TTs) of different lengths. Methods: Nineteen trained male cyclists participated in this study. Before and after TTs of 2000 and 20,000 m, subjects performed submaximal exercise at 55% of the power output attained at maximal oxygen uptake (PVO2max). The postmeasurement continued until 30 min after the end of the TT, during which GE was determined over 3-min intervals. The magnitude-based-inferences approach was used for statistical analysis. Results: GE decreased substantially during the 2000-m and 20,000-m TTs (−11.8% [3.6%] and −6.2% [4.0%], respectively). A most likely and very likely recovery of GE was found during the first half of the submaximal exercise bout performed after the 2000-m, with only a possible increase in GE during the first part of the submaximal exercise bout performed after the 20,000-m. After both distances, GE did not fully recover to the initial pre-TT values, as the difference between the pre-TT value and average GE value of minutes 26–29 was still most likely negative for both the 2000- and 20,000-m (−6.1% [2.8%] and −7.0% [4.5%], respectively). Conclusions: It is impossible to fully recover GE after TTs of 2000- or 20,000-m during 30 min of submaximal cycling exercise performed at an intensity of 55% PVO2max.


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