The effect of interval sprinting exercise on vascular function and aerobic fitness of post-menopausal women.

Menopausal transition accelerates an age-associated decrease in vascular function and a decline in aerobic fitness. The purpose of this study was to examine the effect of 8 weeks of interval sprinting cycle ergometer exercise on arterial stiffness, basal forearm blood flow, and aerobic fitness of post-menopausal women. Sixty overweight post-menopausal women were randomized into either exercise (Ex, n = 30) or control (C, n = 30) groups. Ex participants completed 24 interval sprinting exercise (ISE) sessions over 8 weeks. Each 20-minute ISE session comprised of alternating 8 seconds sprints and 12 seconds of light pedaling. Arterial stiffness assessed through ankle-brachial pulse wave velocity (baPWV) and augmentation index (AIx), basal forearm blood flow (FBF) assessed using venous occlusion, and aerobic fitness were assessed before and after the intervention. baPWV was significantly decreased in the Ex group by 7.2%, P = .03, whereas AIx demonstrated a 10% decrease, P = .002. No changes were found in basal FBF. Aerobic fitness was significantly increased, P = .002, in the Ex group (14%) with no change occurring in the control group.ISE training, despite minimal exercise commitment time (8 hours over 8 weeks), significantly lowered the arterial stiffness and increased the aerobic fitness of post-menopausal women. These results suggest that ISE positively influences the negative change in arterial stiffness and aerobic fitness that typically accompanies menopause.

The Effect of Sprint Interval Training on Body Composition of Postmenopausal Women.

INTRODUCTION: Menopause is accompanied by body composition changes that include a decrease in lean mass and aerobic fitness and an increase in fat mass. Sprint interval training (SIT) may be able to reverse these changes. PURPOSE: To examine the effect of an 8-wk SIT program on body composition and aerobic fitness of overweight postmenopausal women. METHODS: Forty postmenopausal women were randomized into SIT (n = 20) or control (n = 20) groups. The SIT group completed three SIT sessions a week for 8 wk with each session consisting of 20 min of alternating 8-s sprints and 12-s of light pedaling. Total mass, regional lean mass, and fat mass were assessed using dual-energy x-ray absorptiometry. Maximal oxygen uptake (V˙O2max) was predicted using a submaximal test. RESULTS: Total lean mass was significantly increased from pretest (48.1 ± 5.81 kg) to posttest (48.8 ± 5.96 kg) and fat mass was significantly reduced (pre, 29.5 ± 7.29 kg; post, 29.1 ± 7.61 kg) for the SIT group. Lean mass was mostly increased in the trunk (pre, 24.4 ± 2.79 kg; post, 24.8 ± 2.93 kg) and legs (pre, 15.6 ± 2.31 kg; post, 15.9 ± 2.34 kg). V˙O2max was significantly increased from pretest (21.7 ± 4.89 mL⋅kg⋅min) to posttest (24.4 ± 5.96 mL⋅kg⋅min) for the SIT group only. CONCLUSIONS: The SIT intervention increased total lean mass, decreased fat mass, and increased aerobic fitness of postmenopausal women after only 8 h of actual exercise over 8 wk.

Cardiovascular response of postmenopausal women to 8 weeks of sprint interval training.

INTRODUCTION: Menopause is accompanied by decreased aerobic fitness and increased risk of cardiovascular disease. Sprint interval training (SIT) is a time-efficient intervention for improving cardiovascular function and aerobic fitness of young adults. AIM: To determine the effect of an 8-week SIT program on the cardiovascular function and aerobic fitness of overweight postmenopausal women. METHOD: Thirty overweight postmenopausal women were randomized into exercise (n = 15) or control (n = 15) groups. The intervention group completed three SIT sessions a week for 8 weeks. Each session consisted of 20 min of 8-s sprints and 12 s of light pedalling. Participants also completed 8 min of light aerobic cycle exercise, before and after the SIT intervention. Cardiovascular function including heart rate, stroke volume (SV), and diastolic filling time (DFT) was assessed before and after the intervention and during 8 min of light aerobic exercise. Estimated maximal oxygen uptake ([Formula: see text]) was also assessed. RESULTS: Resting SV was increased (p = 0.001) from pre- (77.5 ± 17.0 mL) to post-SIT (81.3 ± 17.0 mL), whereas SV during 8 min of light aerobic exercise was increased (p = 0.000), from pre- (97.8 ± 1.6 mL) to post-test (103.5 ± 17.8 mL). Resting DFT was increased, (p = 0.010), at pre- (333.4 ± 94.4 mL) to post-SIT (357.4 ± 88.2 mL), whereas DFT during 8 min of aerobic exercise was increased, (p = 0.000), from pre- (480.1 ± 99.5 mL) to posttest (527.2 ± 123.0 mL). Predicted [Formula: see text] was increased, (p = 0.016), from pre- (19.5 ± 5.87 mL kg-1 min-1) to post-SIT (21.4 ± 7.02 mL kg-1 min-1). CONCLUSION: SIT improved cardiovascular function and aerobic fitness of overweight postmenopausal women after 8 weeks of exercise.

The combined effect of green tea and acute interval sprinting exercise on fat oxidation of trained and untrained males.

PURPOSE: This study investigated the combined effect of green tea and acute interval sprinting exercise on fat oxidation of trained and untrained males. METHODS: Fourteen trained and 14 untrained males ingested one capsule containing either green tea or cellulose with breakfast, lunch, and dinner, 24 hours before two exercise sessions. A fourth capsule was consumed 90 minutes before exercise after overnight NPO (nil per os). Participants performed a 20-minute interval sprinting cycling protocol, consisting of repeated bouts of 8-seconds of sprint cycling (at 65% of maximum power output) and 12-seconds of recovery (at 25% of maximum power output), followed by 75 minutes of post-exercise recovery. RESULTS: Fat oxidation was significantly greater in the resting condition after green tea ingestion (p < 0.05) compared with the placebo. Fat oxidation was also significantly increased post-exercise in the green tea, compared with the placebo condition (p < 0.01). During and after exercise the plasma glycerol levels significantly increased in both groups after green tea consumption and were significantly higher in the untrained group compared with the trained group (p < 0.05). Compared with the placebo, the plasma epinephrine levels were significantly higher for both groups in the green tea condition during and after exercise, however, norepinephrine levels were only significantly greater, p < 0.05, during and after exercise in the untrained group. CONCLUSION: Green tea significantly increased resting and post-exercise fat oxidation and also elevated plasma glycerol and epinephrine levels during and after interval sprinting. Glycerol and norepinephrine levels during interval sprinting were significantly higher in the untrained group compared with the trained group.

Effect of acute interval sprinting exercise on postprandial lipemia of sedentary young men.

PURPOSE: Postprandial lipemia (PPL) contributesto the development of atherosclerosis. In females, repeated 8-second bouts of interval sprinting exercise reduced PPL, however, the effect of 8-second bouts of interval sprinting on PPL of overweight males is undetermined. Thus, the effect of 8-secondsof interval sprinting for 20 min, the night before ingestion of a high-fat meal (HFM), on plasma triacylglycerol(TG) levelswas examined. METHODS: Ten overweight males acted as participants (BMI = 26±3.0kg/m2, age 22 ± 2.5 years). A crossover design was employed withinterval sprinting and a noexercise condition separated by 7days. Participants consumed a milkshake (high-fat meal;HFM = 4170 kJ/993 Kcal) the morning after an overnight fast, followed by 4 hourly blood samples. Participants performedone bout of interval sprinting (8seconds sprinting at 110-115rpm, 12seconds active recovery at ~60rpm for 20 minutes) the evening before the consumption of the HFM. RESULTS: Postprandial TG was 22.5% lower in the interval sprinting compared to the noexercise condition when comparing the change in total area under the curve (ΔAUCT): ISE(7.15±1.90mmolL(-1)h(-1)) versus noexercise (9.22±3.44mmolL(-1)h(-1)), p=.014. The correlation between fasting TG levels in the noexercise condition and total reduction in AUCT between the conditions was significant (r=.87, p=.001). CONCLUSION: One 20-min bout of interval sprinting,the night before consumption of a HFM,significantly attenuated the PPL response of sedentary males.

The effect of a lifestyle intervention on metabolic health in young women.

With the increasing obesity rates in Western countries, an effective lifestyle intervention for fat reduction and metabolic benefits is needed. High-intensity intermittent exercise (HIIE), Mediterranean eating habits (Mediet), and fish oil (ω-3) consumption positively impact metabolic health and adiposity, although the combined effect has yet to be determined. A 12-week lifestyle intervention on adiposity, insulin resistance, and interleukin-6 (IL-6) levels of young overweight women was administered. Thirty women with a body mass index of 26.6±0.5 kg/m(2), blood pressure of 114/66±1.9/1.5 mmHg, and age of 22±0.8 years were randomly assigned to either an intervention group receiving Mediet advice, daily ω-3 supplementation, and HIIE 3 days/week for 12 weeks or a control group. The group receiving Mediet advice, daily ω-3 supplementation, and HIIE experienced a significant reduction in total body fat mass (P<0.001), abdominal adiposity (P<0.05), waist circumference (P<0.001), systolic blood pressure (P<0.05), fasting plasma insulin (P<0.05), IL-6 (P<0.001), and triglycerides (P<0.05). The greatest decreases in fasting plasma insulin (P<0.05) and IL-6 (P<0.001) occurred by week 6 of the intervention. Significant improvements in eating habits (P<0.05) and aerobic fitness (P<0.001) were also found following the intervention. A multifaceted 12-week lifestyle program comprising a Mediet, ω-3 supplementation, and HIIE induced significant improvements in fat loss, aerobic fitness, and insulin and IL-6 levels, positively influencing metabolic health.

Effect of high-intensity intermittent exercise on postprandial plasma triacylglycerol in sedentary young women.

High-intensity intermittent exercise (HIIE) such as the 30-s Wingate test attenuates postprandial triacylglycerol (TG), however, the ability of shorter versions of HIIE to reduce postprandial TG is undetermined. Thus, the effect of 8-s sprinting bouts of HIIE on blood TG levels of 12 females after consumption of a high-fat meal (HFM) was examined. Twelve young, sedentary women (BMI 25.1 ± 2.3 kg/m²; age 21.3 ± 2.1 years) completed a maximal oxygen uptake test and then on different days underwent either an exercise or a no-exercise postprandial TG condition. Both conditions involved consuming a HFM after a 12-hr fast. The HFM, in milkshake form provided 4170 kJ (993 Kcal) of energy and 98 g fat. Order was counter-balanced. In the exercise condition participants completed 20-min of HIIE cycling consisting of repeated bouts of 8 s sprint cycling (100-115 rpm) and 12 s of active rest (easy pedaling) 14 hr before consuming the HFM. Blood samples were collected hourly after the HFM for 4 hr. Total postprandial TG was 13% lower, p = .004, in the exercise (5.84 ± 1.08 mmol L⁻¹ 4 h⁻¹) compared with the no-exercise condition (6.71 ± 1.63 mmol L⁻¹ 4 h⁻¹). In conclusion, HIIE significantly attenuated postprandial TG in sedentary young women.

Rating of perceived exertion after 12 weeks of high-intensity, intermittent sprinting.

The effect of a 12-week high-intensity intermittent exercise (HIIE) intervention on the rating of perceived exertion (RPE) response of young males was examined. Participants (N = 38; M BMI = 28.7 kg x m(-2), SD = 3.1; M age = 24.9 yr., SD = 4.3) were randomly assigned to either an exercise or control group. The exercise group received HIIE three times per week, 20 min. per session, for 12 weeks. RPE was assessed before and after HIIE training and during pre- and post-maximal oxygen uptake (VO2 max) testing. After HIIE training, RPE was significantly higher in Weeks 11-12 compared to Weeks 1-2. In contrast, heart rate was similar throughout training. Comparing post- to pre-VO2 max test, RPE was significantly lower in the exercise group, whereas for controls, RPE was similar. Aerobic power improved 15% for the exercise group, with no significant change for controls. HIIE resulted in significant increases in RPE, whereas RPE during the VO2 max test was significantly decreased.

The relationship between cardiac autonomic function and maximal oxygen uptake response to high-intensity intermittent-exercise training.

Major individual differences in the maximal oxygen uptake response to aerobic training have been documented. Vagal influence on the heart has been shown to contribute to changes in aerobic fitness. Whether vagal influence on the heart also predicts maximal oxygen uptake response to interval-sprinting training, however, is undetermined. Thus, the relationship between baseline vagal activity and the maximal oxygen uptake response to interval-sprinting training was examined. Exercisers (n = 16) exercised three times a week for 12 weeks, whereas controls did no exercise (n = 16). Interval-sprinting consisted of 20 min of intermittent sprinting on a cycle ergometer (8 s sprint, 12 s recovery). Maximal oxygen uptake was assessed using open-circuit spirometry. Vagal influence was assessed through frequency analysis of heart rate variability. Participants were aged 22 ± 4.5 years and had a body mass of 72.7 ± 18.9 kg, a body mass index of 26.9 ± 3.9 kg · m(-2), and a maximal oxygen uptake of 28 ± 7.4 ml · kg(-1) · min(-1). Overall increase in maximal oxygen uptake after the training programme, despite being anaerobic in nature, was 19 ± 1.2%. Change in maximal oxygen uptake was correlated with initial baseline heart rate variability high-frequency power in normalised units (r = 0.58; P < 0.05). Thus, cardiac vagal modulation of heart rate was associated with the aerobic training response after 12 weeks of high-intensity intermittent-exercise. The mechanisms underlying the relationship between the aerobic training response and resting heart rate variability need to be established before practical implications can be identified.

High-intensity intermittent exercise and cardiovascular and autonomic function.

OBJECTIVE: The effect of 12 weeks of high-intensity intermittent exercise (HIIE) on cardiac, vascular, and autonomic function of young males was examined. METHODS: Thirty-eight young men with a BMI of 28.7 ± 3.1 kg m(-2) and age 24.9 ± 4.3 years were randomly assigned to either an HIIE or control group. The exercise group underwent HIIE three times per week, 20 min per session, for 12 weeks. Aerobic power and a range of cardiac, vascular, and autonomic measures were recorded before and after the exercise intervention. RESULTS: The exercise, compared to the control group, recorded a significant reduction in heart rate accompanied by an increase in stroke volume. For the exercise group forearm vasodilatory capacity was significantly enhanced, P < 0.05. Arterial stiffness, determined by pulse wave velocity and augmentation index, was also significantly improved, after the 12-week intervention. For the exercise group, heart period variability (low- and high-frequency power) and baroreceptor sensitivity were significantly increased. CONCLUSION: High-intensity intermittent exercise induced significant cardiac, vascular, and autonomic improvements after 12 weeks of training.

The effects of high-intensity intermittent exercise training on cardiovascular response to mental and physical challenge.

The purpose was to examine the effect of a 12-week exercise intervention on the cardiovascular and autonomic response of males to mental and physical challenge. Thirty four young overweight males were randomly assigned to either an exercise or control group. The exercise group completed a high-intensity intermittent exercise (HIIE) program three times per week for 12weeks. Cardiovascular response to the Stroop task was determined before and after the intervention by assessing heart rate (HR), stroke volume (SV), arterial stiffness, baroreflex sensitivity (BRS), and skeletal muscle blood flow. The exercise group improved their aerobic fitness levels by 17% and reduced their body weight by 1.6kg. Exercisers compared to controls experienced a significant reduction in HR (p<0.001) and a significant increase in SV (p<0.001) at rest and during Stroop and exercise. For exercisers, arterial stiffness significantly decreased at rest and during Stroop (p<0.01), whereas BRS was increased at rest and during Stroop (p<0.01). Forearm blood flow was significantly increased during the first two minutes of Stroop (p<0.05). HIIE induced significant cardiovascular and autonomic changes at rest and during mental and physical challenge after 12weeks of training.

Regional adiposity distribution and insulin resistance in young Chinese and European Australian women.

OBJECTIVE: Lower than normal leg fat mass and excessive trunk fat mass are predictive of insulin resistance (IR) in obese women of European descent. Whether this regional adiposity relationship applies to moderately overweight women of Chinese descent is undetermined. Thus, the relationship between leg and trunk fat mass and IR of young (22.3 ± 0.3 years) sedentary Australian women of either Chinese (CW; n = 22) or European (EW; n = 36) descent was examined. MATERIAL AND METHODS: Subjects underwent a maximal oxygen uptake test, blood draw, and dual energy x-ray absorptiometry to measure body composition. Fasting insulin levels and C-reactive protein (CRP) were assessed by ELISA and IR was calculated by HOMA-IR. Blood lipids and glucose were quantified by an automated enzymatic method (Cholestech LDX, USA). RESULTS: Total, arm, trunk, and leg fat was significantly greater (p < 0.05) for the EW group, whereas IR was significantly higher for CW. Fasting lipids and glucose were within normal levels for both groups, whereas CRP levels were significantly higher in EW. For EW trunk fat mass was the only variable significantly correlated with IR (r = 0.40, p < 0.05). In contrast, for CW leg fat mass was significantly correlated with IR (r = − 0.49, p < 0.05). CONCLUSIONS: Greater trunk fat mass was associated with higher IR of Australian women of European descent, whereas smaller leg fat mass was associated with higher IR of women of Chinese descent.

High-intensity intermittent exercise and fat loss.

The effect of regular aerobic exercise on body fat is negligible; however, other forms of exercise may have a greater impact on body composition. For example, emerging research examining high-intensity intermittent exercise (HIIE) indicates that it may be more effective at reducing subcutaneous and abdominal body fat than other types of exercise. The mechanisms underlying the fat reduction induced by HIIE, however, are undetermined. Regular HIIE has been shown to significantly increase both aerobic and anaerobic fitness. HIIE also significantly lowers insulin resistance and results in a number of skeletal muscle adaptations that result in enhanced skeletal muscle fat oxidation and improved glucose tolerance. This review summarizes the results of HIIE studies on fat loss, fitness, insulin resistance, and skeletal muscle. Possible mechanisms underlying HIIE-induced fat loss and implications for the use of HIIE in the treatment and prevention of obesity are also discussed.

Vascular and baroreceptor abnormalities in young males with a family history of hypertension.

Vascular and baroreceptor abnormalities in 44 young males, mean age 21 years, comprising of offspring with (FH(+); n = 22) and without (FH(-); n = 22) hypertensive parents, were investigated. Peak forearm blood flow (FBF), which was defined as the highest blood flow obtained following reactive hyperaemia, was assessed using strain gauge plethysmography following 5 min of ischemia. Cardiopulmonary baroreceptor sensitivity was assessed using lower body negative pressure for 5 min at -20 mmHg and was determined by calculating change of stroke volume and forearm vascular resistance (FVR) to lower body negative pressure. Carotid baroreceptor sensitivity was assessed using neck suction at -20, -40, -60, and -80 mmHg and was calculated by dividing RR interval by systolic blood pressure. Augmentation index, a measure of wave reflection, was assessed using applanation tonometry and was calculated as the ratio of augmented pressure and pulse pressure. Peak FBF of FH(+) was 19% lower than the FH(-) (p = 0.02). Also FH(+) had 17% higher peak FVR compared to FH(-) (p = 0.04). However, there were no significant differences between groups for cardiopulmonary, carotid baroreceptor sensitivity, and augmentation index. These results suggest that peripheral vascular dysfunction appears earlier than abnormal baroreceptor sensitivity in young males with a family history of hypertension.

Elevated levels of circulating cortisol in young normotensive adult men with a family history of hypertension.

1. Differences in blood lipids, glucose, insulin, amylin, adrenocorticotropic hormone (ACTH), cortisol, aldosterone, angiotensin II, metabolites of nitric oxide (nitrate, nitrite), asymmetric dimethyl arginine, endothelial leucocyte adhesion molecule-1, vascular cell adhesion molecule-1, C-reactive protein, homocysteine and oxidative status (urate, vitamin A, vitamin E, beta-carotene and total anti-oxidant capacity) were investigated in men (aged 18-25 years) with (+) or without (-) a family history (FH) of hypertension. 2. In the present study, FH+ was defined as having at least one parent or grandparent taking medication for hypertension. Blood (60 mL) was sampled (0800-1000 hours) from a cannulated forearm vein after an overnight fast and 24 h abstinence from caffeine-containing products and alcohol. 3. Comparing FH+ with FH-, systolic blood pressure (124 +/- 1 vs 117 + 3 mmHg, respectively; n = 50 and 14, respectively; P < 0.05) and plasma cortisol (377 +/- 23 vs 298 +/- 24 nmol/L, respectively; n = 43 and 12, respectively; P < 0.05) were found to be significantly higher in the former group. 4. No significant difference was found between the two groups for body mass index, resting heart rate, diastolic and mean blood pressures or any of the biochemical measures studied. 5. A significant correlation was found between cortisol and ACTH (r = 0.73). No correlation was found between cortisol and any other parameter measured. 6. These data indicate that elevated cortisol levels are characteristic of young lean normotensive FH+ men. The future impact of this on their vascular health and hypertension remains to be determined.

Metabolic response of trained and untrained women during high-intensity intermittent cycle exercise.

The metabolic response to two different forms of high-intensity intermittent cycle exercise was investigated in young women. Subjects (8 trained and 8 untrained) performed two bouts of high-intensity intermittent exercise: short sprint (SS) (8-s sprint, 12-s recovery) and long sprint (LS) (24-s sprint, 36-s recovery) for 20 min on two separate occasions. Both workload and oxygen uptake were greater in the trained subjects but were not significantly different for SS and LS. Plasma glycerol concentrations significantly increased during exercise. Lactate concentrations rose over the 20 min and were higher for the trained women. Catecholamine concentration was also higher postexercise compared with preexercise for both groups. Both SS and LS produced similar metabolic response although both lactate and catecholamines were higher after the 24-s sprint. In conclusion, these results show that high-intensity intermittent exercise resulted in significant elevations in catecholamines that appear to be related to increased venous glycerol concentrations. The trained compared with the untrained women tended to show an earlier increase in plasma glycerol concentrations during high-intensity exercise.

Fatness is related to blunted vascular stress responsivity, independent of cardiorespiratory fitness in normal and overweight men.

Obesity is associated with disturbed cardiovascular responsivity to mental stress, which may mediate psychosocial disease pathways. Whether being aerobically fit is protective against psychophysiological dysfunction in the presence of overweight or obesity is undetermined. Peripheral blood flow, blood pressure, and cardiac responses were measured during a 2-min mental stress task in 48 healthy men (aged 18-32 years). Mental stress-evoked increases in mean arterial pressure and heart rate, forearm vasodilatation, and cardiac parasympathetic withdrawal. Multiple linear regression analyses adjusted for age, peak oxygen uptake, and baseline forearm vascular resistance, revealed that greater fatness was related to a blunted vasodilatation response to mental stress (beta=-.31, p<.05). There were no interactive effects of fitness and fatness. Fitness does not appear to moderate the association between fatness and impaired vascular stress responsivity in normal and overweight men.

Reproducibility of skeletal muscle vasodilatation responses to Stroop mental challenge over repeated sessions.

Skeletal muscle blood flow responses to stress have implications for psychobiological disease pathways. An important assumption underlying psychophysiological studies relating stress reactivity with disease risk is that individuals are characterized by stable response profiles that can be reliably assessed using acute psychophysiological stress testing. We examined the reproducibility of forearm vasodilatation, blood pressure, and cardiac responses to a 2 min Stroop mental challenge over two repeated stress sessions that were on average 3.6 months apart. Participants were 21 healthy men and women (aged 21.8+/-3.7 years). Vasodilatation, blood pressure and heart rate responses displayed no habituation between sessions, although there was significantly greater cardiac parasympathetic involvement during the second testing session. Significant test-retest correlations between the sessions were observed for both forearm blood flow and heart rate reactivity. These findings demonstrate skeletal muscle vasodilatation responses to repeated stress are robust, so may be a useful psychophysiological indicator in studies of stress reactivity and disease risk.

Cardiovascular response to Stroop: effect of verbal response and task difficulty.

The purpose was to examine the effect of verbal response and task difficulty on cardiovascular response to the Stroop task. Heart rate, mean arterial blood pressure, forearm blood flow (FBF), and catecholamine response of 13 males was assessed during 3, 5-min differing versions of the Stroop task. Heart rate, epinephrine, and FBF were significantly greater during Stroop 1 (the color-word conflict task) compared to Stroop 3 (a non-verbal version of Stroop where participants responded cognitively without any oral or behavioural response), whereas mean arterial pressure was significantly greater during Stroop 1 than that of Stroop 2 (slides in monochrome without color conflict) and Stroop 3. Rating of level of difficulty and concentration was lower for Stroop 2 compared to the other two Stroop tasks. These results suggest that performance of the traditional Stroop task caused significant cardiovascular, FBF, and epinephrine reactivity. This reactivity was attenuated during reading of monochrome words and was virtually abolished when performing the Stroop without verbally responding.

Acute exercise reduces vascular reactivity to mental challenge in offspring of hypertensive families.

OBJECTIVE: To examine the effects of acute exercise on cardiac and vascular responses to mental challenge in males at risk of hypertension. DESIGN: A within-subjects, counterbalanced design. PARTICIPANTS: Normotensive, healthy males with (n = 22) and without (n = 8) family history of hypertension. METHOD: A moderately stressful behavioural task was performed for 10 min after 20 min of moderate intensity cycle ergometry exercise, and on a separate occasion after an attentional control task. The blood pressure, heart rate, cardiac output, stroke volume, forearm blood flow, forearm vascular resistance, and total peripheral resistance were measured at rest, during the task, and at recovery. Stress reactivity was defined as the difference in values between the task and the baseline. RESULTS: An enhanced peripheral vasodilatation response to the Stroop task was observed in men with familial risk of hypertension compared with the control group. However, this enhanced response was significantly blunted in offspring hypertensive participants following an acute bout of exercise so that differences in the vasodilatation response were no longer observed in comparison with men without familial risk of hypertension. The post-exercise heart rate reactivity in comparison with the control session was also significantly blunted in both groups (P < 0.05). CONCLUSION: Acute exercise may be an important intervention strategy to reduce the impact of cardiovascular hyper-reactivity on disease progression in males with familial risk of hypertension.