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.     

Does type 1 diabetes alter post‐exercise thermoregulatory and cardiovascular function in young adults?

Recent data demonstrated that individuals with type 1 diabetes mellitus (T1DM) exhibit impaired sweating and increased rectal temperature (i.e., heat storage) during exercise compared with healthy controls. Our purpose in this study was to investigate the consequences of T1DM on post‐exercise thermal homeostasis. Sixteen participants (eight controls matched with eight T1DM) performed 90 min of cycling followed by 60 min of seated recovery. Esophageal and rectal temperatures, sweating (forearm, chest, and upper back), skin blood flow [forearm and upper back, presented as cutaneous vascular conductance (CVC)], and blood pressure [mean arterial pressure (MAP)] were measured at baseline and throughout recovery. Esophageal temperature was similar during baseline and recovery between groups (P = 0.88). However, rectal temperature was elevated in our T1DM group throughout recovery (P = 0.05). Sweating and CVC were similar between groups at all sites from 10‐min post‐exercise until the end of recovery (P ≥ 0.16). While absolute MAP was similar between groups (P = 0.43), the overall decrease in MAP post‐exercise was greater in controls from 20 min (T1DM: ? 8 ± 5 vs control: ? 13 ± 6 mmHg, P = 0.03) until the end of recovery. We conclude that despite increased heat storage during exercise, individuals with T1DM exhibit a suppression in heat loss similar to their healthy counterparts during recovery.     

Cutaneous blood flow rate in areas with and without arterovenous anastomoses during exercise

In 10 healthy subjects, skin blood flow rate was measured in the thumb pulp by the heat-washout method, and in the skin fold between the thum and the forefinger by the ¹³³Xe-washout method. The former but not the latter skin area contains arterovenous anastomoses (AVAs). In response to 10 min moderate cycle exercise, an instantaneous decrease in flow was seen in the thumb pulp followed after about 4.6 min by an increase to resting levels. Blood flow in the skin fold remained constant. The results indicate that the initial reduction in blood flow rate and later increase observed in the finger at the onset of moderate exercise take place in the AVAs and not in the capillaries.     

The effect of callisthenic exercise on physical fitness values of sedentary women

Introduction

The purpose of this study was done to determine the effects of a 12-week callisthenic exercise program on some physical and physiological parameters of young, middle-aged and menopausal women.

Synthesis

We studied, during 12 weeks, 172 subjects’ age, height and body weight means were determined. Physical characteristics of Group I were (between19–30 years) 26.72 ± 3.57 years, 158.18 ± 4.66 cm and 71.45 ± 10.32 kg, for Group II (between 31–44 years) were as 41.43 ± 4.69 years, 156.94 ± 5.27 cm and 73,89 ± 10,66 kg, and Group III (between 45–56 years) were as 50.60 ± 4.05 years, 154.45 ± 4.18 cm and 75.51 ± 11.71 kg, respectively. All subjects attended the study, 50 minutes per session, three sessions per week, aerobic and calisthenic exercise programs. The intensity of the exercise was determined by Karvonen method (60 or 70%). There were significant differences in increase among aerobic power, sit-up, push-up, and handgrip strength values in Groups I, II and III. There was a significant difference among Group I, II and III in decreased blood pressure (p < 0.05).

Conclusion

It was determined that physical fitness values had decreased as the age increased. As a result, it can be said that the long-term callisthenic exercises cause the similar positive changes on women at different ages.     

The effect of liniment on blood flow

The effect of liniment applied by massage or stick on skin and calf blood flow was studied in 12 subjects. The blood flow was recorded with laser Doppler flowmetry with skin probe and strain gauge plethysmography. A massage liniment used to lower the friction that is not supposed to have any therapeutic effect (Frisco) was massaged into the right lower leg for 10 min and the registration was performed for 60 min. Then the liniment studied, Tiger Balm was massaged into the left lower leg and another registration was carried out. This procedure was performed a second time and the liniments were applied with a stick and wiped off after 10 min. Liniments with massage resulted in an increase in both skin and calf blood flow. The effect was greater and longer lasting when using Tiger Balm. When the liniments were applied with a stick, a decrease in skin and calf blood flow was noted when using Frisco. Tiger Balm caused a slight increase in the skin blood flow but had no influence on the calf blood flow.     

准备运动与放松运动对剧烈运动中及运动后颈总动脉血流速度的影响

８名男性大学生参加了下列３组实验：（１）单纯５分钟的剧烈运动（大于９０％ｏｆＶＯ２ｍａｘ）;（２）５分钟的准备运动（５０％ｏｆＶＯ２ｍａｘ）后再进行上述剧烈运动;（３）上述剧烈运动后再进行５分钟的放松运动（５５％ｏｆＶＯ２ｍａｘ）。在上述实验的同时,检测了每位被试者的颈总动脉血流平均速度（平均ＶＣＣＡ）、心率（ｆｃ）、左肱动脉平均血压（Ｐｍ）,并根据血流速度参数计算出反映脑血流阻力的指标———阻抗指数（ＲＩ）。结果显示：在５分钟的剧烈运动中,不论有否准备运动,上述４种参数均明显增加。在准备运动中,平均ＶＣＣＡ和ｆｃ均有所增加,ＲＩ的增加几乎达到了剧烈运动时的水平。剧烈运动后,Ｐｍ和ｆｃ很快恢复,放松运动中这两个指标有所恢复。但是平均ＶＣＣＡ和ＲＩ在放松运动中保持着剧烈运动时的高水平。准备运动中阻抗指数明显增加提示脑血流阻力增加,这可防止由于颈总动脉平均血流速度和心率的增加而引起脑血流的过多增加（尤其是对那些有脑血管缺陷的人）,有利于机体接着进行剧烈的运动。本研究中的放松运动可减缓颈总动脉血流平均速度等几种生理指标在剧烈运动后的恢复速度,使剧烈运动后机体（尤其是心脑血管调节功能差的人）的生理功能逐渐得到恢复,?     

Effects of aerobic exercise in early evening onthe following nocturnal sleep and its haemodynamic response

We determined effect of aerobic exercise in early evening on the quality, quantity, and haemodynamic response of subsequent nocturnal sleep in the home. Ten healthy young participants performed two protocols, with/without cycle ergometer exercise (60 min at 50% heart rate reserve) in early evening. Blood pressure (BP) (Holter) and physical activity (accelerometer) were measured from late afternoon of day 1 until noon of next day (day 2). Additionally, at bedtime participants were equipped with a small device worn on the wrist that identified sleep stage. There were no substantial differences in objective indices of sleep between two protocols (total sleep time: 438 ± 76 vs. 457 ± 64 min; P > 0.10). BP during nocturnal sleep tended to be lowered by prior exercise (MAP: 71 ± 5 vs. 68 ± 6 mmHg; P = 0.08). Aerobic exercise in early evening apparently has no acute effect on sleep per se, but seems to have a residual effect on haemodynamics, i.e. prolongation of post-exercise hypotension.     

Trunk exercise training improves muscle size,strength, and function in older adults: A randomized controlled trial

The aim of this study was to assess the effectiveness of a multimodal exercise program to increase trunk muscle morphology and strength in older individuals, and their associated changes in functional ability. Using a single‐blinded parallel‐group randomized controlled trial design, 64 older adults (≥60 years) were randomly allocated to a 12‐week exercise program comprising walking and balance exercises with or without trunk strengthening/motor control exercises; followed by a 6‐week walking‐only program (detraining; 32 per group). Trunk muscle morphology (ultrasound imaging), strength (isokinetic dynamometer), and functional ability and balance (6‐Minute Walk Test; 30 second Chair Stand Test; Sitting and Rising Test; Berg Balance Scale, Multi‐Directional Reach Test; Timed Up and Go; Four Step Square Test) were the primary outcome measures. Sixty‐four older adults (mean [SD]; age: 69.8 [7.5] years; 59.4% female) were randomized into two exercise groups. Trunk training relative to walking‐balance training increased (mean difference [95% CI]) the size of the rectus abdominis (2.08 [1.29, 2.89] cm²), lumbar multifidus (L4/L5:0.39 [0.16, 0.61] cm; L5/S1:0.31 [0.07, 0.55] cm), and the lateral abdominal musculature (0.63 [0.40, 0.85] cm); and increased trunk flexion (29.8 [4.40, 55.31] N), extension (37.71 [15.17, 60.25] N), and lateral flexion (52.30 [36.57, 68.02] N) strength. Trunk training relative to walking‐balance training improved 30‐second Chair Stand Test (5.90 [3.39, 8.42] repetitions), Sitting and Rising Test (1.23 [0.24, 2.23] points), Forward Reach Test (4.20 [1.89, 6.51] cm), Backward Reach Test (2.42 [0.33, 4.52] cm), and Timed Up and Go Test (?0.76 [?1.40, ?0.13] seconds). Detraining led to some declines but all outcomes remained significantly improved when compared to pre‐training. These findings support the inclusion of trunk strengthening/motor control exercises as part of a multimodal exercise program for older adults.     

Quantifying in vivo hemodynamic response to exercise in patients with intermittent claudication and abdominal aortic aneurysms using cine phase‐contrast MRI

Purpose:

To evaluate rest and exercise hemodynamics in patients with abdominal aortic aneurysms (AAA) and peripheral occlusive disease (claudicants) using phase‐contrast MRI.

Materials and Methods:

Blood velocities were acquired by means of cardiac‐gated cine phase‐contrast in a 0.5 Tesla (T) open MRI. Volumetric flow was calculated at the supraceliac (SC), infrarenal (IR), and mid‐aneurysm (MA) levels during rest and upright cycling exercise using an MR‐compatible exercise cycle.

Results:

Mean blood flow increased during exercise (AAA: 130%, Claudicants: 136% of resting heart rate) at the SC and IR levels for AAA participants (2.6 ± 0.6 versus 5.8 ± 1.6 L/min, P < 0.001 and 0.8 ± 0.4 versus 5.1 ± 1.7 L/min, P < 0.001) and claudicants (2.3 ± 0.5 versus 4.5 ± 0.9 L/min, P < 0.005 and 0.8 ± 0.2 versus 3.3 ± 0.9 L/min, P < 0.005). AAA participants had a significant decrease in renal and digestive blood flow from rest to exercise (1.8 ± 0.7 to 0.7 ± 0.6 L/min, P < 0.01). The decrease in renal and digestive blood flow during exercise correlated with daily activity level for claudicants (R = 0.81).

Conclusion:

Abdominal aortic hemodynamic changes due to lower extremity exercise can be quantified in patients with AAA and claudication using PC‐MRI. The redistribution of blood flow during exercise was significant and different between the two disease states. J. Magn. Reson. Imaging 2010; 31: 425–429. © 2010 Wiley‐Liss, Inc.

     

The effect of hypoxia and exercise on heart rate variability,immune response,and orthostatic stress

Hypoxia with exercise is commonly used to enhance physiological adaptation in athletes, but may prolong recovery between training bouts. To investigate this, heart rate variability (HRV), systemic immune response, and response to an orthostatic challenge were measured following exercise in hypoxia and air. Eleven trained men performed a 10‐km cycling time trial breathing hypoxia (16.5 ± 0.5% O₂) or air. HRV and the heart rate response to an orthostatic challenge were measured for 3 days before and after each trial, while venous blood samples were collected pre‐, 0, 2, and 24 h post‐exercise. Hypoxia had no significant effect compared with air. Subgroup analysis of those who had a drop in oxyhemoglobin saturation (SpO₂) > 10% between hypoxia and air compared with those who did not, demonstrated a significantly altered HRV response (△HFnu: ?2.1 ± 0.9 vs 8.6 ± 9.3, △LFnu: 2.1 ± 1.0 vs ?8.6 ± 9.4) at 24 h post‐exercise and increased circulating monocytes (1.3 ± 0.2 vs 0.8 ± 0.2 × 10⁹/L) immediately post‐hypoxic exercise. Exercise and hypoxia did not change HRV or the systemic immune response to exercise. However, those who had a greater desaturation during hypoxic exercise had an attenuate recovery 24 h post‐exercise and may be more susceptible to accumulating fatigue with subsequent training bouts.     

SPECT evaluation of cerebral blood flow during arm exercise in patients with subclavian steal

Objectives To explore the cerebral hemodynamics in subclavian steal syndrome, we examined the cerebral perfusion of seven patients with subclavian steal (one symptomatic and six asymptomatic) using single-photon emission computed tomography (SPECT) during resting, arm exercise, and acetazolamide-activated conditions. Methods The regional CBF (rCBF) was measured with SPECT under all conditions, and region of interest (ROI) analysis was performed using a three-dimensional stereotaxic ROI template (3DSRT). We evaluated the relationship between arm exercise-induced rCBF change and (1) presence of subclavian artery stenosis, (2) vertebral reverse flow severity, (3) presence of vertebro-basilar insufficiency (VBI) symptoms, and (4) cerebrovascular reactivity (CVR) to acetazolamide. Results Overall, no arm exercise-induced rCBF reduction was observed on either the affected or the unaffected side, even in patients with severe vertebral reverse flow. One patient with VBI symptoms showed an arm exercise-induced global rCBF reduction in the cerebrum and cerebellum, whereas the other asymptomatic patients did not. The %rCBF changes in segments with severely impaired CVR (−8.6%± 10.7%, mean ± SD) were significantly lower than those in other segments with less impaired CVR (P < 0.01). Conclusions Our results suggest that subclavian steal is a benign condition in asymptomatic patients. On the other hand, arm exercise-induced rCBF reduction can occur in the cerebrum and cerebellum in patients with VBI symptoms possibly related to low CVR.     

The effects of physical fitness and body composition on oxygen consumption and heart rate recovery after high-intensity exercise

The aim of this study was to investigate the potential relationship between excess post-exercise oxygen consumption (EPOC), heart rate recovery (HRR) and their respective time constants (tvo2 and t HR) and body composition and aerobic fitness (VO2max) variables after an anaerobic effort. 14 professional cyclists (age=28.4±4.8 years, height=176.0±6.7 cm, body mass=74.4±8.1 kg, VO2max=66.8±7.6 mL·kg - 1·min - 1) were recruited. Each athlete made 3 visits to the laboratory with 24 h between each visit. During the first visit, a total and segmental body composition assessment was carried out. During the second, the athletes undertook an incremental test to determine VO2max. In the final visit, EPOC (15-min) and HRR were measured after an all-out 30 s Wingate test. The results showed that EPOC is positively associated with % body fat (r=0.64), total body fat (r=0.73), fat-free mass (r=0.61) and lower limb fat-free mass (r=0.55) and negatively associated with HRR (r= - 0.53, p<0.05 for all). HRR had a significant negative correlation with total body fat and % body fat (r= - 0.62, r= - 0.56 respectively, p<0.05 for all). These findings indicate that VO2max does not influence HRR or EPOC after high-intensity exercise. Even in short-term exercise, the major metabolic disturbance due to higher muscle mass and total muscle mass may increase EPOC. However, body fat impedes HRR and delays recovery of oxygen consumption after effort in highly trained athletes.     

Effects of capsaicin application on the skin during resting exposure to temperate and warm conditions

We investigated thermoregulatory and cardiovascular responses at rest in a temperate (20°C) and in a warm (30°C) environment (40% RH) without and with the application of capsaicin on the skin. We hypothesized that regardless of environmental temperature, capsaicin application would stimulate heat loss and concomitantly deactivate heat conservation mechanisms, thus resulting in rectal temperature (Tre) and mean blood pressure decline due to excitation of heat‐sensitive TRPV1. Ten male subjects were exposed, while seated, for 30 minutes to 20.8 ± 1.0°C or to 30.6 ± 1.1°C: without (NCA) and with (CA) application of capsaicin patches on the skin. Thermoregulatory (Tre, proximal‐distal skin temperature gradient) and cardiovascular variables (modelflow technique) as well as oxygen uptake were continuously measured. The area under the curve for Tre decline at 20°C was smaller in CA (?2.1 ± 1.3 a.u.) than in NCA (?0.6 ± 1.1 a.u., P < 0.01, r = 0.8). Likewise, at 30°C it was smaller in CA (?2.2 ± 2.1 a.u.) compared to NCA (?0.8 ± 2.0 a.u., P = 0.02, r = 0.7). Local vasomotor tone and oxygen uptake, were significantly lower by 36.7% ± 94.2% and 12.3% ± 12.3%, respectively, with capsaicin compared to NCA (P = 0.05 and P < 0.01, respectively). Additionally, in 30°C CA mean arterial pressure was lower by 10.7% ± 5.9%, 8.9% ± 5.9%, and 10.6% ± 7.0% compared to 30°C NCA, 20°C NCA, and 20°C CA, respectively (P < 0.01, P = 0.02, and P < 0.01, respectively, d = 1.4‐1.8). In conclusion, capsaicin application on the skin induced vasodilation and Tre decline. At 30°C CA, thermal responses were accompanied by arterial hypotension most likely due to the interactive effects of both stressors (warm environment and capsaicin) on cutaneous vascular regulation.     

The effect of drugs on the cardiovascular response to exercise

Anti-hypertensives, diuretics, digitalis, beta-blockers, nitrates, anti-arrhythmics, and psychiatric drugs are reviewed for their effects on the cardiovascular response to exercise, in particular work capacity, heart rate, blood pressure, anginal threshold, and exertional arrhythmias. The limitations of these measurements to assess changes in the various aspects of cardiovascular performance in the presence of drugs becomes evident, emphasizing the need for an understanding of the relationship between drug effects on specific target organs and the altered integrated exercise response. The variable response of individuals to drug therapy, depending on the pathophysiological effects of their disease, demonstrates the value of exercise testing in selecting optimal drug regimens.     

The effect of prior high-intensity cycling exercise on the VO2 kinetics during high-intensity cycling exercise is situated at the additional slow component

In previous studies conclusions about the effect of prior exercise on VO2 kinetics of subsequent high-intensity exercise are generally based on observed changes in the overall VO2 response without considering the effects on the VO2 fast and slow component. The aim of the present study was to examine the effect on the VO2 fast and slow component separately. Therefore 10 subjects performed an exercise protocol consisting of an initial 3 min period of unloaded cycling followed by two constant-load work bouts at a work rate corresponding to 90% VO2peak, separated by 3 min of rest and 3 min of unloaded cycling. VO2 was measured on a breath-by-breath basis, and the response curves were analysed by a biexponential model. To increase signal-to-noise ratio, subjects performed four repetitions of the exercise protocol, each separated by at least one day. There was no significant alteration in VO2 kinetic parameters of the primary, fast component after high-intensity exercise. However, there was a significant effect of prior high-intensity exercise on the VO2 kinetic parameters of the slow component. The time constant and the amplitude of the slow component were reduced by respectively 44% (from 231.0 +/- 111.7 s to 130.1 +/- 50.4 s) and 49% (from 824 +/- 270 ml x min(-1) to 417 +/- 134 ml x min(-1)). The results of this study indicate that the effect of high-intensity exercise on the VO2 kinetics of a subsequent high-intensity exercise is probably limited to an effect on the slow component.     

Eryptosis and hemorheological responses to maximal exercise in athletes: Comparison between running and cycling

We compared the effects of cycling and running exercise on hemorheological and hematological properties, as well as eryptosis markers. Seven endurance‐trained subjects randomly performed a progressive and maximal exercise test on a cycle ergometer and a treadmill. Blood was sampled at rest and at the end of the exercise to analyze hematological and blood rheological parameters including hematocrit (Hct), red blood cell (RBC ) deformability, aggregation, and blood viscosity. Hemoglobin saturation (SpO2), blood lactate, and glucose levels were also monitored. Red blood cell oxidative stress, calcium content, and phosphatidylserine exposure were determined by flow cytometry to assess eryptosis level. Cycling exercise increased blood viscosity and RBC aggregation whereas it had no significant effect on RBC deformability. In contrast, blood viscosity remained unchanged and RBC deformability increased with running. The increase in Hct, lactate, and glucose concentrations and the loss of weight at the end of exercise were not different between running and cycling. Eryptosis markers were not affected by exercise. A significant drop in SpO2 was noted during running but not during cycling. Our study showed that a progressive and maximal exercise test conducted on a cycle ergometer increased blood viscosity while the same test conducted on a treadmill did not change this parameter because of different RBC rheological behavior between the 2 tests. We also demonstrated that a short maximal exercise does not alter RBC physiology in trained athletes. We suspect that exercise‐induced hypoxemia occurring during running could be at the origin of the RBC rheological behavior differences with cycling.     

Influence of high-intensity exercise training on the ventilatory response to exercise in patients with reduced ventricular function.

BACKGROUND: Exercise training increases exercise capacity in patients with reduced ventricular function in part through improved skeletal muscle metabolism, but the effect training might have on abnormal ventilatory and gas exchange responses to exercise has not been clearly defined. METHODS: Twenty-five male patients with reduced ventricular function after a myocardial infarction were randomized to either a 2-month high-intensity residential exercise training program or to a control group. Before and after the study period, upright exercise testing was performed with measurements of ventilatory gas exchange, lactate, arterial blood gases, cardiac output, and pulmonary artery and wedge pressures. RESULTS: In the exercise group, peak VO2 and VO2 at the lactate threshold increased 29 and 39%, respectively, whereas no increases were observed among controls. Maximal cardiac output increased only in the exercise group (1.7 L x min(-1), P < 0.05), and no changes in rest or peak exercise pulmonary pressures were observed in either group. At baseline, modest inverse relationships were observed between pulmonary wedge pressure and peak VO2 both at rest (r = -0.56, P < 0.05) and peak exercise (r = -0.43, P < 0.05). Maximal VE/VCO2 was inversely related to maximal cardiac output (r = -0.72, P < 0.001). Training did not have a significant effect on these relationships. Training lowered VE/VO2, heart rate, and blood lactate levels at matched work rates throughout exercise and tended to lower maximal Vd/Vt. The slope of the relationship between VE and VCO2 was reduced after training in the exercise group (0.33 pre vs 0.27 post, P < 0.01), whereas control patients did not differ. CONCLUSIONS: Exercise training among patients with reduced left ventricular function results in a systematic improvement in the ventilatory response to exercise. Training increased maximal cardiac output, tended to lower Vd/Vt, and markedly improved the efficiency of ventilation. Peak VO2 and ventilatory responses to exercise were only modestly related to pulmonary vascular pressures, and training had no effect on the relationships between exercise capacity, ventilatory responses, and pulmonary pressures.