Calcium Losses Resulting from an Acute Bout of Moderate-Intensity Exercise

1999 ◽  
Vol 9 (3) ◽  
pp. 275-284 ◽  
Author(s):  
Daryll B. Bullen ◽  
Mary L. O'Toole ◽  
Karen C. Johnson

The purpose of this study was to compare daily calcium (Ca) losses in sweat (S) and urine (U) on an exercise day (E) with losses on the preceding day (i.e., a rest day) during which no exercise (NE) was performed. Ten healthy male volunteers (23.9 ± 3.2 years) performed a single bout of moderate exercise (running at 80% HRmax) for 45 min in a warm (32 °C, 58% relative humidity) environment on E. When E and NE were compared, neither Ca intake (1,232 ± 714 and 1,148 ±482 mg, respectively) nor urinary Ca excretion (206 ± 128 and 189 ± 130 mg, respectively) were different (p > .05). Sweat Ca losses during the exercise bout averaged 45 ± 12 mg. The results indicate that, although a small amount of Ca is lost in sweat during 45 min of moderate-intensity exercise, measured (sweat and urine losses combined) Ca losses (251 ±128 and 189 ± 130 mg) were not different (p > .05) between days (E and NE, respectively). These data suggest that moderate exercise for up to 45 min in a warm, humid environment does not markedly increase Ca intake requirements.

2021 ◽  
Vol 10 (3) ◽  
Author(s):  
Sandra A. Billinger ◽  
Alicen A. Whitaker ◽  
Allegra Morton ◽  
Carolyn S. Kaufman ◽  
Sophy J. Perdomo ◽  
...  

Background The primary aim of this study was to characterize the middle cerebral artery blood velocity (MCAv) dynamic response to an acute bout of exercise in humans at 3‐ and 6‐months poststroke. As a secondary objective, we grouped individuals according to the MCAv dynamic response to the exercise bout as responder or nonresponder. We tested whether physical activity, aerobic fitness, and exercise mean arterial blood pressure differed between groups. Methods and Results Transcranial Doppler ultrasound measured MCAv during a 90‐second baseline followed by a 6‐minute moderate intensity exercise bout. Heart rate, mean arterial blood pressure, and end‐tidal CO 2 were additional variables of interest. The MCAv dynamic response variables included the following: baseline, time delay, amplitude, and time constant. Linear mixed model revealed no significant differences in our selected outcomes between 3‐ and 6‐months poststroke. Individuals characterized as responders demonstrated a faster time delay, higher amplitude, and reported higher levels of physical activity and aerobic fitness when compared with the nonresponders. No between‐group differences were identified for baseline, time constant, or exercise mean arterial blood pressure. In the nonresponders, we observed an immediate rise in MCAv following exercise onset followed by an immediate decline to near baseline values, while the responders showed an exponential rise until steady state was reached. Conclusions The MCAv dynamic response profile has the potential to provide valuable information during an acute exercise bout following stroke. Individuals with a greater MCAv response to the exercise stimulus reported statin use and regular participation in exercise.


1999 ◽  
Vol 87 (5) ◽  
pp. 1752-1757 ◽  
Author(s):  
Scott A. Spier ◽  
M. Harold Laughlin ◽  
Michael D. Delp

Reductions in blood pressure that are associated with exercise training have been hypothesized to be the result of a sustained postexertional vascular alteration following single bouts of exercise. The purpose of this study was to determine whether a decrease in vascular sensitivity to vasoconstrictor agonists occurs after a single bout of exercise and whether this vascular alteration is sustained through various periods of exercise training. Vascular responses of abdominal aortic rings to norepinephrine (NE; 10−9–10−4M) were determined in vitro. Aortas were isolated from sedentary rats immediately after rats performed a single bout of treadmill exercise (30 m/min for 1 h); 24 h after the last exercise bout in rats exercised for 1 day; and 1, 2, 4, and 10 wk of training at 30 m/min, 60 min, 5 days/wk. Sensitivity to NE was only diminished after 10 wk of training. This diminished vascular sensitivity to NE was abolished with the removal of the endothelial cell layer. Furthermore, there were no reductions in developed tension or vascular sensitivity to the vasoconstrictor agonists KCl (10–100 mM), phenylephrine (10−8–10−4M), and arginine vasopressin (10−9–10−5M) in vessels either with or without the endothelial layer after a single bout of exercise. These data indicate that a single bout of exercise does not diminish aortic responsiveness to vasoconstrictor agonists and thus is not responsible for the diminished contractile responsiveness that occurs between 4 and 10 wk of moderate-intensity exercise training in rats. This vascular adaptation to exercise training appears to be mediated through an endothelium-dependent mechanism.


Author(s):  
Douglas Lopes Almeida ◽  
Gabriel Sergio Fabricio ◽  
Laize Peron Tófolo ◽  
Tatiane Aparecida Ribeiro ◽  
Camila Cristina Ianoni Matiusso ◽  
...  

Abstract Exercise counteracts obesity effects, but information on how early-life obesity may affect long-term adaptation to exercise is lacking. This study investigates the impact of early-life postnatal overfeeding (PO) on animals’ adaptation to exercise. Only male Wistar rats were used. On postnatal day (PN) 30, rats from control (NL-9 pups) or PO (SL-3 pups) litters were separated into four groups: NL-sedentary (NL-Se), NL-exercised (NL-Ex), SL-sedentary (SL-Se), and SL-exercised (SL-Ex). Exercised groups performed moderate-intensity exercise, running on a treadmill, from PN30 to PN90. Further experiments were carried out between PN90 and PN92. PO promoted obesity in SL versus NL rats (P < 0.05). Exercise reduced body weight (P < 0.001), body fat (P < 0.01), and improved glucose homeostasis in SL-Ex versus SL-Se. SL-Ex presented lower VO2max (P < 0.01) and higher post-exercise LDH (P < 0.05) compared to NL-Ex rats. Although moderate exercise counteracted obesity in SL rats, early-life overnutrition restricts fitness gains in adulthood, indicating that early obesity may impair animals’ adaptation to exercise.


1998 ◽  
Vol 274 (2) ◽  
pp. E304-E308 ◽  
Author(s):  
Janice A. Koval ◽  
Ralph A. DeFronzo ◽  
Robert M. O’Doherty ◽  
Richard Printz ◽  
Hossein Ardehali ◽  
...  

A single bout of exercise increases the rate of insulin-stimulated glucose uptake and metabolism in skeletal muscle. Exercise also increases insulin-stimulated glucose 6-phosphate in skeletal muscle, suggesting that exercise increases hexokinase activity. Within 3 h, exercise increases hexokinase II (HK II) mRNA and activity in skeletal muscle from rats. It is not known, however, if a single bout of moderate-intensity exercise increases HK II expression in humans. The present study was undertaken to answer this question. Six subjects had percutaneous biopsies of the vastus lateralis muscle before and 3 h after a single 3-h session of moderate-intensity aerobic (60% of maximal oxygen consumption) exercise. Glycogen synthase, HK I, and HK II activities as well as HK I and HK II mRNA content were determined from the muscle biopsy specimens. The fractional velocity of glycogen synthase was increased by 446 ± 84% after exercise ( P < 0.005). Hexokinase II activity in the soluble fraction of the homogenates increased from 1.2 ± 0.4 to 4.5 ± 1.6 pmol ⋅ min−1 ⋅ μg−1( P < 0.05) but was unchanged in the particulate fraction (4.3 ± 1.3 vs. 5.3 ± 1.5). HK I activity in neither the soluble nor particulate fraction changed after exercise. Relative to a 28S rRNA control signal, HK II mRNA increased from 0.091 ± 0.02 to 0.195 ± 0.037 ( P < 0.05), whereas HK I mRNA was unchanged (0.414 ± 0.061 vs. 0.498 ± 0.134, P < 0.20). The increase in HK II activity after moderate exercise in healthy subjects could be one factor responsible for the enhanced rate of insulin-stimulated glucose uptake seen after exercise.


2018 ◽  
Vol 3 (2) ◽  
pp. 484-487
Author(s):  
Santosh Kumar Deo ◽  
Kopila Agrawal ◽  
Prem Bhattrai ◽  
Raju Kumar Chaudhary

Introduction: Working memory is a kind of short term memory important for reasoning and guiding decision-making and behavioral process.Objective: The goal of the present research was to study the outcome of single bout of acute moderate-intensity exercise on working memory.Methodology: Twenty two male subjects were asked to perform working memory task by 2n back task in baseline resting, immediately after exercise and after five minute of exercise session. 3 minute step test procedure was used as a moderate intensity exercise intervention.Results: The percentage correctness of 2n back task of working memory was found to be 64.36% for baseline resting condition, 78.01 % for immediately after 3-minute step test and 80.70% for 5 minute after the exercise. In both exercise session (i.e. immediately after exercise and after 5 minute of exercise), significant improvement (p value <0.05) in working memory was seen as compared to the baseline resting session while no such significant beneficial improvement was seen when compared between immediately after exercise and after 5 minute of exercise.Conclusion: Improvement in working memory after moderate exercise intervention was seen, which is important for learning and memory and decision-making.  BJHS 2018;3(2)6:484-487.


2021 ◽  
Vol 33 (2) ◽  
pp. 82-89
Author(s):  
Yasmeen Mezil ◽  
Joyce Obeid ◽  
Inna Ushcatz ◽  
Sandeep Raha ◽  
Brian W. Timmons

Purpose: In girls and women, the authors studied the effects of an acute bout of low-impact, moderate-intensity exercise serum on myoblast and osteoblast proliferation in vitro. Methods: A total of 12 pre/early pubertal girls (8–10 y old) and 12 women (20–30 y old) cycled at 60% VO2max for 1 hour followed by 1-hour recovery. Blood samples were collected at rest, mid-exercise, end of exercise, mid-recovery, and end of recovery. C2C12 myoblasts and MC3T3E1 osteoblasts were incubated with serum from each time point for 1 hour, then monitored for 24 hours (myoblasts) or 36 hours (osteoblasts) to examine proliferation. Cells were also monitored for 6 days (myoblasts) to examine myotube formation and 21 days (osteoblasts) to examine mineralization. Results: Exercise did not affect myoblast or osteoblast proliferation. Girls exhibited lower cell proliferation relative to women at end of exercise (osteoblasts, P = .041; myoblasts, P = .029) and mid-recovery (osteoblasts, P = .010). Mineralization was lower at end of recovery relative to rest (P = .014) in both girls and women. Myotube formation was not affected by exercise or group. Conclusion: The systemic environment following one acute bout of low-impact moderate-intensity exercise in girls and women does not elicit osteoblast or myoblast activity in vitro. Differences in myoblast and osteoblast proliferation between girls and women may be influenced by maturation.


Animals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 486
Author(s):  
Wendy Pearson ◽  
Julia Guazzelli Pezzali ◽  
Renan Antunes Donadelli ◽  
Ashley Wagner ◽  
Preston Buff

There is little information available to describe the inflammatory consequences of and recovery from moderate-intensity exercise bouts in hunting dogs. The purpose of the current study is to generate pilot data on the appearance and disappearance of biomarkers of inflammation and inflammation resolution following a typical one-hour exercise bout in basset hounds. Four hounds were set out to find a scent and freely adopted running or walking over wooded terrain for approximately one hour. Venous blood samples were obtained before the exercise and at 1, 2, 4, 6, and 10 h following cessation of exercise and were analyzed for biomarkers of inflammation (prostaglandin E2 (PGE2), nitric oxide (NO), interleukin 1β (IL-1β)) tumour necrosis factor-α (TNF-α)), and inflammation resolution (resolvin D1 (RvD1)). There was an increase in inflammation one hour after the exercise, shown by a significant increase in PGE2. Following this peak, PGE2 steadily declined at the same time as RvD1 increased, with RvD1 peaking at six hours. This pilot study provides evidence that dogs that undergo an hour of hunt exercise experience transient inflammation that peaks one hour after the end of exercise; inflammation resolution peaks six hours after the end of exercise. Future studies should seek to further understand the distinct and combined roles of PGE2 and RvD1 in dog adaptation to exercise stress.


Healthcare ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 425
Author(s):  
Marianna Masiero ◽  
Helen Keyworth ◽  
Gabriella Pravettoni ◽  
Mark Cropley ◽  
Alexis Bailey

The primary aim of this study was to assess the effectiveness of a short bout (10 min) of moderate-intensity exercise to reduce withdrawal symptomatology, craving and negative affect; while the secondary aim was to assess how the effectiveness of a short bout of moderate exercise can be modulated by the perception of intensity in physically active and low-activity smokers. Fifty low-activity and physically active smokers were recruited (24 male and 26 female) and randomized in three different conditions. Prescribed (objective) moderate intensity (OBJ) and perceived moderate intensity (PER), and passive waiting (PW). After the intervention (T3), smokers reported less desire to smoke in the PER (p < 0.001) and OBJ (p < 0.001) conditions, relative to the PW condition. At T3 smokers in the PER condition reported less negative affect than smokers in the PW condition relative to the baseline (T1) (p < 0.007). Further, smokers in the PER condition reported less negative affect than smokers in the PW condition (p < 0.048). Physically active (PA) smokers perceived less exertion than low-activity (LA) smokers, and the effects were stronger in the PER condition relative to OBJ. Generally, our results suggest that a short bout of moderate exercise helps both LA and PA smokers. These findings provided a novel insight into the psychological mechanisms that affect the efficacy of the exercise in smoking cessation and suggest that exercise should be tailored according to individual perception of intensity.


2010 ◽  
Vol 105 (4) ◽  
pp. 506-516 ◽  
Author(s):  
Nicholas M. Hurren ◽  
Frank F. Eves ◽  
Andrew K. Blannin

Moderate-intensity exercise can lower the TAG response to a high-fat meal; however, the British diet is moderate in fat, and no study to date has compared the effect of such exercise on responses to high-fat and moderate-fat meals. The present work investigated the effect of brisk walking performed 13 h before intake of both high-fat and moderate-fat meals on postprandial plasma TAG concentrations. Eight inactive, overweight men completed four separate 2 d trials, i.e. rest (Con) or a 90-min treadmill walk (Ex) on the evening of day 1, followed by the ingestion of a moderate-fat (Mod) or high-fat (High) meal on the morning of day 2. High-fat meals contained 66 % of total energy as fat, while the percentage was 35 % for moderate-fat meals; both the meals were, however, isoenergetic. On day 2, venous blood was sampled in the fasted state, 30 and 60 min after ingesting the test meal and then hourly until 6 h post-meal. Exercise reduced plasma TAG concentrations significantly (P < 0·001), with no exercise × meal interaction (P = 0·459). Walking reduced the total TAG response to a high-fat meal by 29 % (relative to High Con); the same bout of exercise performed before ingesting a moderate-fat meal lowered total TAG by 26 % (compared with Mod Con). The ability of a single moderate-intensity aerobic exercise bout to lower postprandial TAG concentrations is just as great, in percentage terms, when the test meal ingested is of a moderate rather than a high fat content.


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