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Brian C. Focht, Deborah J. Knapp, Timothy P. Gavin, Thomas D. Raedeke and Robert C. Hickner

This study examined the psychological responses to an acute bout of aerobic exercise in sedentary older and younger adults. Eighteen young (mean age 24 years) and 15 older adults (mean age 64 years) completed a 20-min bout of stationary cycling at 65% of VO2peak. Affective responses were assessed before, during, and immediately after exercise. Participants’ exercise self-efficacy beliefs were assessed before and immediately after exercise. Both groups reported reduced pleasant feeling states and self-efficacy and increased physical exhaustion in response to acute exercise. Older adults also demonstrated a significant decrease in revitalization during and after cycling. Correlation analyses revealed that self-efficacy was related to feelings of fatigue during exercise and postexercise feelings of energy and fatigue. Both groups reported negative shifts in affect and self-efficacy during and 5 min after cycling. Acute affective and self-efficacy responses might influence one’s motivation to adopt and maintain regular physical activity. The relationship between these acute responses and physical activity behavior across the life span warrants future inquiry.

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Joel B. Mitchell, James R. Rowe, Meena Shah, James J. Barbee, Austen M Watkins, Chad Stephens and Steve Simmons

To examine the effect of prior exercise on the postprandial lipid response to a high-carbohydrate meal in normal-weight (NW = BMI h25) and overweight (OW = BMI ≥25) women (age 18–25), 10 NW and 10 OW participants completed 2 conditions separated by 1 month. In the morning, the day after control (CT = no exercise) or exercise conditions (EX = 60 min cycling at 60% VO2peak), participants consumed a high-carbohydrate meal (80% CHO, 15% protein, 5% fat; 75 kJ/kg BM) followed by 6 hr of hourly blood sampling. Blood was analyzed for triglycerides (TG), blood glucose (BG), and insulin (IN). TG levels over the 6-hr period were lower in NW than OW (p = .021) and lower in EX than in CT (p = .006). Area under the curve (AUC) for TG was lower in NW than OW (p = .016) and EX than CT (p = .003). There were nonsignificant tendencies for reduced BG over time (p = .053) and AUC (p = .083), and IN AUC was lower in EX than in CT (p = .040) for both groups and lower in NW than in OW (p = .039). Prior exercise improved TG levels after a high-carbohydrate meal in both groups, and OW women demonstrated a greater postprandial lipemic response than NW regardless of condition. There were tendencies for improved glucose removal with prior exercise in NW vs. OW. Acute exercise can improve postprandial TG responses and might also improve postprandial BG and IN after a large meal in NW and OW young women.

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Daniel G. Syrotuik, Kirsten L. MacFadyen, Vicki J. Harber and Gordon J. Bell

To examine the effects of elk velvet antler supplementation (EVA) combined with training on resting and exercise-stimulated hormonal response, male (n = 25) and female (n = 21) rowers ingested either E VA (560 mg/d) or placebo (PL) during 10 wk of training. VO2max, 2000 m rowing time, leg and bench press strength were determined before and after 5 and 10 wk of training. Serum hormone levels were measured prior to and 5 and 60 min after a simulated 2000 m rowing race. VO2max and strength increased and 2000 m times decreased similarly (P < 0.05) with training. There was no significant difference between the EVA and PL group for any hormonal response. Testosterone (males only) and growth hormone (both genders) were higher 5 min after the simulated race (P < 0.05) but returned to baseline at 60 min. Cortisol was higher 5 and 60 min compared to rest (both genders) (P < 0.05) and was higher 60 min post-exercise following 5 and 10 wk of training. It appears that 10 wk of EVA supplementation does not significantly improve rowing performance nor alter hormonal responses at rest or after acute exercise than training alone.

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Rachael C. Gliottoni, John R. Meyers, Sigurbjörn Á. Arngrímsson, Steven P. Broglio and Robert W. Motl

This experiment examined the effect of a moderate dose of caffeine on quadriceps muscle pain during a bout of high-intensity cycling in low- versus high-caffeine-consuming males. College-age men who were low (≤100 mg/day; n = 12) or high (≥400 mg/day; n = 13) habitual caffeine consumers ingested caffeine (5 mg/kg body weight) or a placebo in a counterbalanced order and 1 hr later completed 30 min of cycle ergometry at 75–77% of peak oxygen consumption. Perceptions of quadriceps muscle pain, as well as oxygen consumption, heart rate, and work rate, were recorded during both bouts of exercise. Caffeine ingestion resulted in a statistically significant and moderate reduction in quadriceps muscle-pain-intensity ratings during the 30-min bout of high-intensity cycle ergometry compared with placebo ingestion in both low (d = −0.42) and high (d = −0.55) caffeine consumers. The results suggest that caffeine ingestion is associated with a moderate hypoalgesic effect during high-intensity cycling in college-age men who are low or high habitual caffeine consumers, but future work should consider better defining and differentiating pain and effort when examining the effects of caffeine during acute exercise.

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Andrea T. Duran, Erik Gertz, Daniel A. Judelson, Andrea M. Haqq, Susan J. Clark, Kavin W. Tsang and Daniela Rubin

Prader-Willi Syndrome (PWS), the best characterized form of syndromic obesity, presents with abnormally high fat mass. In children, obesity presents with low-grade systemic inflammation. This study evaluated if PWS and/or nonsyndromic obesity affected cytokine responses to intermittent aerobic exercise in children. Eleven children with PWS (11 ± 2 y, 45.4 ± 9.5% body fat), 12 children with obesity (OB) (9 ± 1 y, 39.9 ± 6.8% body fat), and 12 lean (LN) children (9 ± 1 y, 17.5 ± 4.6% body fat) participated. Children completed 10 2-min cycling bouts of vigorous intensity, separated by 1-min rest. Blood samples were collected preexercise (PRE), immediately postexercise (IP), and 15, 30, and 60 min into recovery to analyze possible changes in cytokines. In all groups, IL-6 and IL-8 concentrations were greater during recovery compared with PRE. PWS and OB exhibited higher IL-6 area under the curve (AUC) than LN (p < .01 for both). PWS demonstrated higher IL-8 AUC than LN (p < .04). IL-10, TNF-α, and IFN-γ did not change with exercise (p > .05 for all). Results indicate that children with PWS respond with increased Il-6 and IL-8 concentrations to acute exercise similarly to controls. Excess adiposity and epigenetic modifications may explain the greater integrated IL-6 and IL-8 responses in PWS compared with controls.

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Amy S. Welch, Angie Hulley and Mark Beauchamp

To investigate the relationship between cognitive and affective responses during acute exercise, 24 low-active females completed two 30-min bouts of cycle ergometer exercise at 90% of the ventilatory threshold. In one condition participants had full knowledge of the exercise duration (KD); in the other, exercise duration was unknown (UD). Affect and self-efficacy were measured before and every 3 min during exercise, and affect was also measured postexercise. Affect declined throughout the first half of both conditions, and continued its decline until the end of the UD condition, when a rebound effect was observed. Self-efficacy during exercise displayed a similar pattern. Hierarchical regression analyses demonstrated that during-exercise self-efficacy was a stronger predictor of during-exercise affect than preexercise self-efficacy, and that this relationship was strongest at the end of exercise when duration was unknown. These results indicate that repetitive cognitive appraisal of self and the task could impact the exercise experiences of low-active women during the adoption phase of an exercise program.

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Christine M. Tallon, Ryan G. Simair, Alyssa V. Koziol, Philip N. Ainslie and Alison M. McManus

Purpose: To understand the extent different types of acute exercise influence cerebral blood flow during and following exercise in children. Methods: Eight children (7–11 y; 4 girls) completed 2 conditions: high-intensity interval exercise (HIIE; 6 × 1-min sprints at 90% watt maximum) and moderate-intensity steady-state exercise (MISS; 15 min at 44% watt maximum). Blood velocity in the middle cerebral artery (MCAV) and heart rate were assessed continuously. The partial pressure of end-tidal carbon dioxide and mean arterial pressure were assessed at baseline and following exercise. Results: Percentage of maximum heart rate during HIIE was 82% (4%), compared with 69% (4%) during MISS. MCAV was increased above baseline in MISS after 75 seconds (5.8% [3.9%], P × .004) but was unchanged during HIIE. MCAV was reduced below baseline (−10.7% [4.1%], P × .004) during the sixth sprint of HIIE. In both conditions, MCAV remained below baseline postexercise, but returned to baseline values 30-minute postexercise (P < .001). A postexercise increase in mean arterial pressure was apparent following HIIE and MISS, and persisted 30-minute postexercise. Partial pressure of end-tidal carbon dioxide declined post HIIE (−3.4 mm Hg, P < .05), but not following MISS. Conclusion: These preliminary findings show HIIE and MISS elicit differing intracranial vascular responses; however, research is needed to elucidate the implications and underlying regulatory mechanisms of these responses.

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Jonathan M. Peake

Ascorbic acid or vitamin C is involved in a number of biochemical pathways that are important to exercise metabolism and the health of exercising individuals. This review reports the results of studies investigating the requirement for vitamin C with exercise on the basis of dietary vitamin C intakes, the response to supplementation and alterations in plasma, serum, and leukocyte ascorbic acid concentration following both acute exercise and regular training. The possible physiological significance of changes in ascorbic acid with exercise is also addressed. Exercise generally causes a transient increase in circulating ascorbic acid in the hours following exercise, but a decline below pre-exercise levels occurs in the days after prolonged exercise. These changes could be associated with increased exercise-induced oxidative stress. On the basis of alterations in the concentration of ascorbic acid within the blood, it remains unclear if regular exercise increases the metabolism of vitamin C. However, the similar dietary intakes and responses to supplementation between athletes and nonathletes suggest that regular exercise does not increase the requirement for vitamin C in athletes. Two novel hypotheses are put forward to explain recent findings of attenuated levels of cortisol postexercise following supplementation with high doses of vitamin C.

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Jaqueline P. Batista, Igor M. Mariano, Tállita C.F. Souza, Juliene G. Costa, Jéssica S. Giolo, Nádia C. Cheik, Foued S. Espindola, Sarah Everman and Guilherme M. Puga

The aim of this study was to compare the hemodynamic and salivary responses after mat Pilates, aerobics, resistance exercises, and control. A total of 16 normotensive postmenopausal women performed: Pilates, 10 floor exercises; aerobics, 35 min on a treadmill (60–70% of heart rate reserve); resistance exercises, 60% of one-repetition maximum; and control, no physical exercise. Blood pressure and heart rate variability were evaluated at rest and 60 min after the intervention. Saliva samples were collected at rest, immediately after, and 30 and 60 min after exercise for analysis of nitrite concentration and total proteins. Systolic blood pressure, diastolic blood pressure, and mean blood pressure area under the curve were lower (p < .05) after both aerobic and resistance exercises sessions but not after the Pilates session when compared with the control session. Nitrite concentrations in saliva were higher 60 min after the end of all exercise sessions. Heart rate variability was higher after the resistance exercise. Aerobic and resistance exercises were capable of decreasing arterial blood pressure after acute exercise.

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Patrick J. O’Connor, Melanie S. Poudevigne, M. Elaine Cress, Robert W. Motl and James F. Clapp III

Objective:

Describe safety and efficacy of a supervised, low-to-moderate intensity strength training program adopted during pregnancy among women at increased risk for back pain.

Methods:

32 women adopted strength training twice per week for 12 weeks. Data on musculoskeletal injuries, symptoms, blood pressure, and the absolute external load used for 5 of 6 exercises were obtained during each session. A submaximal lumbar extension endurance exercise test was performed at weeks 5, 10, and 13.

Results:

The mean (± SD) exercise session attendance rate was 80.5% (± 11.3%). No musculoskeletal injuries occurred. Potentially adverse symptoms (eg, dizziness) were infrequent (2.1% of sessions). Repeated-measures ANOVA showed large increases in the external load across 12 weeks (all P values < .001) and the percentage increases in external load from weeks 1 to 12 were 36% for leg press, 39% for leg curl, 39% for lat pull down, 41% for lumbar extension and 56% for leg extension. Training was associated with a 14% increase in lumbar endurance. Blood pressure was unchanged following acute exercise sessions and after 12 weeks of exercise training.

Conclusion:

The adoption of a supervised, low-to-moderate intensity strength training program during pregnancy can be safe and efficacious for pregnant women.