Enjoyment of high-intensity interval training in an overweight/obese cohort: a short report

Exercise enjoyment has been shown to be important for adherence. Minimal data exist on enjoyment of intense exercise, especially in clinical populations. The purpose of this study was to evaluate enjoyment levels of overweight and obese subjects undergoing 3 weeks of high-intensity interval training. Forty-two generally healthy overweight and obese men and women (body mass index = 30·8 ± 4·8 kg × m⁻²) volunteered for this study. Exercise enjoyment was quantified using the Exercise Enjoyment Scale before and after each of nine total interval training sessions, over a three-week period. Heart rate and ratings of perceived exertion (RPE) were measured at the end of each interval and training session. There were no significant differences in enjoyment between training groups (P > 0·05). Exercise enjoyment improved significantly over the three-week training phase (P < 0·05). Enjoyment levels were relatively high to begin training: mean ± SD: 4·2 ± 1·0 out of a 7 point scale. Heart rate and RPE were significantly reduced (P < 0·05) from pre- (day 1) to post-training (day 9). High-intensity interval training may be an enjoyable form of exercise for overweight and obese men and women. Enjoyment levels may continue to increase following initial introduction to this type of training. Due to the small time demand and high enjoyment, interval training may be an effective exercise approach in a sedentary population.     

Effects of intense exercise training on endothelium-dependent exercise-induced vasodilatation

To determine whether intense exercise training affects exercise-induced vasodilatation, six subjects underwent 4 weeks of handgrip training at 70% of maximal voluntary contraction. Exercise forearm vascular conductance (FVC) responses to an endothelium-dependent vasodilator (acetylcholine, ACH; 15, 30, 60 μg min^?1) and an endothelium-independent vasodilator (sodium nitroprusside, SNP; 1·6, 3·2, 6·4 μg min^?1) and FVC after 10 min of forearm ischaemia were determined before and after training. Training elicited significant (P<0·001) increases in grip strength (43·4 ± 2·3 vs. 64·1 ± 3·5 kg, before vs. after, mean ± SEM), forearm circumference (26·7 ± 0·4 vs. 27·9 ± 0·4 cm) and maximal FVC (0·4630 ± 0·0387 vs. 0.6258 ± 0·0389 units, P<0·05). Resting FVC did not change significantly with training (0·0723 ± 0·0162 vs. 0.0985 ± 0·0171 units, P>0·4), but exercise FVC increased (0·1330 ± 0·0190 vs. 0.2534 ± 0·0387 units, P<0·05). Before and after the training, ACH increased exercise FVC above the control (no drug) exercise FVC, whereas SNP did not. Training increased (P<0·05) the exercise FVC responses to ACH (0·3344 ± 0·1208 vs. 0.4303 ± 0·0858 units, before vs. after training, 60 μg min^?1) and SNP (0·2066 ± 0·0849 vs. 0.3172 ± 0·0628 units, 6·4 μg min^?1). However, these increases were due to the increase in control (no drug) exercise FVC, as the drug-associated increase in exercise FVC above control did not differ between trials (P>0·6). These results suggest that exercise FVC is increased by both exercise training and stimulating the release of endothelium-dependent vasodilators. However, training does not affect the vascular response to these vasodilators.     

Women with metabolic syndrome present different autonomic modulation and blood pressure response to an acute resistance exercise session compared with women without metabolic syndrome

Metabolic syndrome (MetS) is a cluster of risk factors in individuals with high risk of diabetes and heart disease. Resistance training (RT) has been proposed to be a safe, effective and worthwhile method for the prevention and treatment of metabolic and cardiovascular diseases. However, no study has analysed the acute response of blood pressure (BP) and autonomic control of heart rate (HR) after a RT session in female patients with MetS. The aim of the present study was to analyse the response of laboratory assessed and ambulatory BP and cardiac autonomic modulation after a RT session in women with MetS. Nine women without MetS (35·0 ± 6·7 years) and 10 women with MetS (34·1 ± 9·4 years) completed one experimental exercise session and a control session. Laboratory BP, heart rate variability (HRV) and ambulatory BP of each subject were measured at rest, over 60 min, and for 24 h after the end of the sessions, respectively. There was a significant reduction in systolic blood pressure (SBP), night time diastolic blood pressure (DBP) and mean blood pressure (MBP) only for women with MetS, for all periods after the RT session when compared with the control session (P<0·05). Significantly lower laboratory values of SBP and DBP (10, 30 and 40 min postexercise) and MBP (10, 40 and 50 min postexercise) were observed in women with MetS (P<0·05). Patients with MetS exhibited significant lower basal HRV and a lower autonomic responsiveness during the 60 min of acute recovery. These results confirmed that an acute session of resistance exercise induced a lower BP during day time and sleeping hours in women with MetS that may offer a cardio‐protective effect. Women with MetS exhibited an impaired autonomic modulation at rest and a lower acute autonomic responsiveness to a RT session. The dissociation between BP and HRV responses suggests that other factors than autonomic control could be involved in the hypotensive effect of a RT session in MetS patients.     

Menopause is associated with the stiffness of the common carotid artery in 50-year-old women

To determine if menopause has an effect on the elasticity of the arteries, the stiffness index of the common carotid artery was studied in 84 premenopausal and 139 post-menopausal women. The study group was age-homogeneous, all women being 50 years of age. There were no significant differences between pre- and post-menopausal women regarding atherosclerosis, when measured as the number of subjects with plaques or intimal-medial thickness. The diameter of the common carotid artery was significantly larger in post-menopausal women. The diameter was correlated to measurements of body size which did not, however, differ between the two groups. The mean stiffness indexes were 4·99 ± 1·02 and 5·38 ± 1·21 in the pre- and post-menopausal groups respectively (P<0·05). In a multivariate analysis, menopause (P<0·05), and also serum insulin levels (P<0·01) and smoking (P<0·05) were found to have independent significant associations to the stiffness index. In conclusion, menopause is associated with reduced elasticity of the carotid arteries in 50-year-old women.     

Influence of arterial wave reflection on carotid blood pressure and intima‐media thickness in older endurance trained men and women with pre‐hypertension

Increased carotid intima‐media thickness (IMT) with aging is a significant predictor of mortality. Older endurance trained (ET) individuals have lower carotid artery stiffness but similar carotid IMT when compared to sedentary (SED) age‐matched peers. The purpose of this study was to examine the contribution of arterial wave reflections to carotid hemodynamics and IMT in older ET and SED with pre‐hypertension. Subjects consisted of endurance‐trained master athletes and age‐matched sedentary controls (mean age 67 years). Carotid artery Beta‐stiffness index and IMT was assessed with ultrasonography. Carotid pressure and augmented pressure from wave reflections (obtained from pulse contour analysis) was measured with applanation tonometry. Carotid systolic blood pressure (SBP) and IMT were not different between groups (P>0·05). Carotid stiffness was significantly lower in ET versus SED (7·3 ± 0·8 versus 9·9 ± 0·6, P<0·05). Augmented pressure was significantly greater in ET versus SED (17·7 ± 1·6 versus 13·3 ± 1·5 mmHg, P<0·05). When adjusting for differences in resting heart rate, there were no group differences in augmented pressure. In conclusion, older ET persons with pre‐hypertension have reduced carotid artery stiffness, but similar carotid SBP and carotid IMT when compared to SED. The lack of change in carotid SBP and IMT in older ET may be related to the inability of chronic exercise training to reduce bradycardia‐related augmented pressure from wave reflections with aging.     

Identification of anaerobic threshold by analysis of heart rate variability during discontinuous dynamic and resistance exercise protocols in healthy older men

The purposes of this study were to determine anaerobic threshold (AT) during discontinuous dynamic and resistive exercise protocols by analysing of heart rate variability (HRV) and blood lactate (BL) in healthy elderly subjects and compare the cardiovascular, metabolic and autonomic variables obtained from these two forms of exercise. Fourteen elderly (70 ± 4 years) apparently healthy males underwent the following tests: (i) incremental ramp test on cycle ergometer, (ii) one repetition maximum (1RM) leg press at 45°, (iii) a discontinuous exercise test on a cycle ergometer (DET‐C) protocol and (iv) a resistance exercise leg press (DET‐L) protocol. Heart rate, blood pressure and BL were obtained during each increment of exercise intensity. No significant differences (P>0·05) were found between methods of AT determination (BL and HRV) nor the relative intensity corresponding to AT (30% of maximum intensity) between the types of exercise (DET‐C and DET‐L). Furthermore, no significant differences (P>0·05) were found between the DET‐C and DET‐L in relation to HRV, however, the DET‐L provided higher values of systolic blood pressure and BL (P<0·05) from the intensity corresponding to AT. We conclude that HRV was effective in determination of AT, and the parasympathetic modulation responses obtained during dynamic and resistive exercise protocols were similar when compared at the same relative intensity. However, DET‐L resulted in higher values of blood pressure and BL at workloads beyond AT.     

Physical training plasma lipoproteins and faecal steroid excretion in sedentary men

Summary. Thirty sedentary men aged 25–52 participated in a 4-month randomized and controlled study of the effects of exercise on plasma lipoproteins and faecal steroid excretion. After 4 months the aerobic training group showed a significant (P= 0·047) increase in physical work capacity (+38 watts) and a significant (P= 0·025) decrease in faecal total steroid excretion (-257 mg/day) compared to corresponding changes in the control group. The drop in faecal total steroid excretion in the men who trained was mainly due to a significant (P<0·05) fall in faecal neutral sterol excretion (-240 mg/day). Plasma lipoprotein lipid concentrations did not change significantly during the study although plasma levels of very low density lipoprotein (VLDL) cholesterol and low density lipoprotein (LDL) cholesterol tended to fall in the men who trained. In the aerobic training group individual changes in plasma LDL cholesterol levels were significantly correlated with decreases in faecal total steroid excretion (p = 0·615, P<0·05) and faecal neutral sterol excretion (p = 0·627, P<0·05). The results of this study show that regular exercise is associated with a drop in faecal neutral sterol excretion which, if sufficiently large, may be associated with a decrease in plasma LDL cholesterol concentration.     

Sequence effects of combined resistance exercises with step choreography in the same session in women's oxygen uptake during and postexercise

The combination of step choreography (SC) with resistance training exercises (RE) in the same session is common in class fitness rooms populated mainly by women to increase energy expenditure. The aim of this study was to evaluate the differences in the exercise oxygen uptake and postexercise between two different combinations of resistance training exercises and step choreography, regarding the order of execution. Thirteen active women (30·31 ± 4·42 years, 62·02 ± 5·37 kg, 162·65 ± 4·40 cm, 19·14 ± 3·29% body fat) performed two combinations: step choreography before resistance training, where resistance training was divided into two blocks of analysis (10 min each); and step choreography divided into three equal blocks (10 min for each block), before, in the middle and after resistance exercise. There were significant differences (P<0·05) between the two sessions in oxygen uptake postexercise in the period of 0–5 min. A significant increase (P<0·0001) in the oxygen uptake absolute and relative in the heart rate between blocks 1 and 2 of resistance exercise in the two sessions was observed. In the step choreography in blocks, a significant (P = 0·001) decrease between blocks 2 and 3 in the step choreography before resistance exercise and a significant (P<0·05) increase in the heart rate in both sessions between blocks were observed. The combination of step choreography and resistance exercises during the same exercise session is a good strategy to promote an elevation of women's oxygen uptake during and after an exercise session, independent of the sequence used.     

The influence of water ingestion on postexercise hypotension and standing haemodynamics

In young healthy adults, postexercise hypotension (PEH) occurs after a single bout of dynamic exercise due to peripheral vasodilation. Gravitational stress may further aggravate the magnitude of PEH, thus predisposing to orthostatic intolerance. As water drinking activates sympathetic vasoconstriction, it might offset PEH via enhanced α‐adrenergic vascular responsiveness. We hypothesized that water ingestion before exercise would decrease the magnitude of PEH and improve the haemodynamic reaction to active standing postmaximal exercise. In a randomized fashion, 17 healthy adults (nine men; eight women, 21·2 ± 1·6 years) ingested 50 and 500 ml of water before completing resting, cycle ergometer and recovery protocols on two separate days. After exercise, measurements [arterial blood pressure (BP), heart rate and spectral heart rate variability (HRV)] were taken in the seated position followed by 5 min of active standing. Compared to that seen post‐50 ml of water, the 500 ml volume elicited an overall increase in BP (P < 0·05). Nevertheless, the magnitude of PEH was not different after either volume of water. There was an overall bradycardic effect of water, and this was accompanied by increased high‐frequency power (P < 0·05). Finally, no BP, heart rate or HRV differences were found between conditions in response to active standing. These data suggest that, despite being well preserved after maximal exercise, the water pressor response does not affect the magnitude of PEH. They also indicate that drinking 500 ml of water does not impact the BP, heart rate or HRV response to 5 min of active standing during recovery postmaximal exercise.     

Cardiac power output and its response to exercise in athletes and non‐athletes

Cardiac power output (CPO) is an integrative measure of overall cardiac function as it accounts for both, flow‐ and pressure‐generating capacities of the heart. The purpose of the present study was twofold: (i) to assess cardiac power output and its response to exercise in athletes and non‐athletes and (ii) to determine the relationship between cardiac power output and reserve and selected measures of cardiac function and structure. Twenty male athletes and 32 age‐ and gender‐matched healthy sedentary controls participated in this study. CPO was calculated as the product of cardiac output and mean arterial pressure, expressed in watts. Measures of hemodynamic status, cardiac structure and pumping capability were assessed by echocardiography. CPO was assessed at rest and after peak bicycle exercise. At rest, the two groups had similar values of cardiac power output (1·08 ± 0·2 W versus 1·1 ± 0·24 W, P>0·05), but the athletes demonstrated lower systolic blood pressure (109·5 ± 6·2 mmHg versus 117·2 ± 8·2 mmHg, P<0·05) and thicker posterior wall of the left ventricle (9·8 ± 1 mm versus 9 ± 1·1 mm, P<0·05). Peak CPO was higher in athletes (5·87 ± 0·75 W versus 5·4 ± 0·69 W, P<0·05) as was cardiac reserve (4·92 ± 0·66 W versus 4·26 ± 0·61 W, P<0·05), respectively. Peak exercise CPO and reserve were only moderately correlated with end‐diastolic volume (r = 0·54; r = 0·46, P<0·05) and end‐diastolic left ventricular internal diameter (r = 0·48; r = 0·42, P<0·05), respectively. Athletes demonstrated greater maximal cardiac pumping capability and reserve than non‐athletes. The study provides new evidence that resting measures of cardiac structure and function need to be considered with caution in interpretation of maximal cardiac performance.     

Muscular adaptations to fatiguing exercise with and without blood flow restriction

The purpose of this study was to determine the muscular adaptations to low‐load resistance training performed to fatigue with and without blood flow restriction (BFR). Middle‐aged (42–62 years) men (n = 12) and women (n = 6) completed 18 sessions of unilateral knee extensor resistance training to volitional fatigue over 6 weeks. One limb trained under BFR, and the contralateral limb trained without BFR [free flow (FF)]. Before and after the training, measures of anterior and lateral quadriceps muscle thickness (MTh), strength, power and endurance were assessed on each limb. The total exercise training volume was significantly greater for the FF limb compared with the BFR limb (P<0·001). Anterior quadriceps thickness and muscle function increased following the training in each limb with no differences between limbs. Lateral quadriceps MTh increased significantly more (P<0·05) in the limb trained under BFR (BFR: 3·50 ± 0·61 to 3·67 ± 0·62 cm; FF: 3·49 ± 0·73 to 3·56 ± 0·70 cm). Low‐load resistance training to volitional fatigue both with and without BFR is viable options for improving muscle function in middle‐aged individuals. However, BFR enhanced the hypertrophic effect of low‐load training and reduced the volume of exercise needed to elicit increases in muscle function.     

Plasma lipid and lipoprotein profiles in pre- and post-menopausal middle-aged runners

Summary. Plasma lipid and lipoprotein profiles were compared in middle-aged trained and untrained women before and after menopause. Subjects were assigned to one of four groups: (1) pre-menopausal trained (Pre-T: n= 17, aged 42 ±5 years, body fat 19±5%, training distance 53 ±20 km week^-1, V?o_2max 49 ±4 ml kg^-1 min^-1, mean±SD); (2) pre-menopausal untrained (Pre-UT: n= 26, 42 ±5 years, 24 ±7%, 34 ±6 ml kg^-1 min^-1); (3) post-menopausal trained (Post-T: n= 16, 54 ±3 years, 20 ±4%, 43 ±19 km week^-1, 41 ±5 ml kg^-1 min^-1); and (4) post-menopausal untrained (Post-UT: n= 15, 55 ±3 years, 25 ±6%, 31 ±3 ml kg^-1 min^-1). There were no significant differences in total cholesterol (range 173–194 mg dl^-1), triglyceride (56–72 mg dl^-1), and HDL-cholesterol (HDLC: 76–85 mg dl^-1) among the four groups. LDL-cholesterol (LDLC) in the post-menopausal women (Post-T: 96 ±32 mg dl^-1; Post-UT: 104 ±23 mg dl^-1) tended to be higher than in the premenopausal women (Pre-T: 86 ± 25 mg dl^-1, Pre-UT: 81 ± 23 mg dl^-1). LDLC/HDLC ratio in Post-UT (1·42 ±0·38 unit) was higher than in the pre-menopausal women (Pre-T: 1·03±0·31 unit, P<0·01; Pre-UT: 1·10±0·38 unit, P<0·05), whereas the ratio in Post-T (1·20 ±0·38 unit) was not different from those of the pre-menopausal groups. These results suggest that endurance running protects against the increase in LDLC/HDLC ratio that frequently occurs after menopause.     

Leg uptake of calcitonin gene‐related peptide during exercise in spinal cord injured humans

Exercise‐induced increases in cardiac output (CO) and oxygen uptake (VO₂) are tightly coupled, as also in absence of central motor activity and neural feedback from skeletal muscle. Neuromodulators of vascular tone and cardiac function – such as calcitonin gene related peptide (CGRP) – may be of importance. Spinal cord injured individuals (six tetraplegic and four paraplegic) performed electrically induced cycling (FES) with their paralyzed lower limbs for 29 ± 2 min to fatigue. Voluntary cycling performed both at VO₂ similar to FES and at maximal exercise in six healthy subjects served as control. In healthy subjects, CGRP in plasma increased only during maximal exercise (33·8 ± 3·1 pmol l^?1 (rest) to 39·5 ± 4·3 (14%, P<0·05)) with a mean extraction over the working leg of 10% (P<0·05). Spinal cord injured individuals had more pronounced increase in plasma CGRP (33·2 ± 3·8 to 46·9 ± 3·6 pmol l^?1, P<0·05), and paraplegic and tetraplegic individuals increased in average by 23% and 52%, respectively, with a 10% leg extraction in both groups (P<0·05). The exercise induced increase in leg blood flow was 10–12 fold in both spinal cord injured and controls at similar VO₂ (P<0·05), whereas CO increased more in the controls than in spinal man. Heart rate (HR) increased more in paraplegic subjects (67 ± 7 to 132 ± 15 bpm) compared with controls and tetraplegics (P<0·05). Mean arterial pressure (MAP) was unchanged during submaximal exercise and increased during maximal exercise in healthy subjects, but decreased during the last 15 min of exercise in the tetraplegics. It is concluded that plasma CGRP increases during exercise, and that it is taken up by contracting skeletal muscle. The study did not allow for a demonstration of the origin of the CGRP, but its release does not require activation of motor centres. Finally, the more marked increase in plasma CGRP and the decrease in blood pressure during exercise in tetraplegic humans may indicate a role of CGRP in regulation of vascular tone during exercise.     

Effects of swim training on body weight,carbohydrate metabolism,lipid and lipoprotein profile

The beneficial effects of regularexercise are primarily based on data using land-based exercise. Currently, no data exist thatdemonstrate the efficacy of swimming exercise for the treatment of obesity and cardiovascularrisk factors, despite the fact that swimming is a widely recommended exercise mode. Eighteenpreviously sedentary obese individuals were divided into a swim-training group and a non-exercising control group. The training group swam at 60% of maximal heart rate reservefor 45 min per day for 3 days per week for 10 weeks, whereas the control group remainedsedentary. The swim-training programme produced significant cardiovascular training effects,as evidenced by reductions (P<0·05) in resting and submaximal heartrate values in the training group. Significant reductions (P<0·05) werealso observed in the rating of perceived exertion and blood lactate concentrations during fixedsubmaximal exercise on an arm cycle ergometer. Caloric and macronutrient intake estimatedfrom the dietary records stayed constant before and after training. Body mass, body fatpercentage (36±2% vs. 35±2%) and body mass index, as well asregional adiposity, showed no statistically significant changes. Neither the training nor thecontrol groups experienced significant changes in fasting serum glucose and insulinconcentrations and glucose–insulin ratio during the study. Total, high-densitylipoprotein (HDL)- and low-density lipoprotein (LDL)-cholesterol did not change significantlyin either group. It was concluded that swim training of the duration, frequency and intensityused in the present study failed to elicit favourable modifications in these traditionalcardiovascular risk factors.     

Autonomic nervous function at rest in aerobically trained and untrained oldermen

Therelationship between aerobictraining, vagal influence on the heart and ageing was examined by assessing aerobic fitness andresting heart rate variability in trained and untrained older men. Subjects were 11 trained cyclistsand runners (mean age=6±61·6 years) and 11 untrained, age-matchedmen (mean age=66±1·2 years). Heart rate variability testing involvedsubjects lying supine for 25 min during which subjects’ breathing was paced andmonitored (7·5 breaths min^?1). Heart rate variability was assessedthrough time series analysis (HRV_ts) of the interbeat interval. Results indicated thattrained older men (3·55±0·21 l min^?1) hadsignificantly (P<0·05) greater VO _2maxthan that of control subjects (2·35±0·15 l min^?1).Also, trained older men (52±1·8 beats min^?1) hadsignificantly (P<0·05) lower supine resting heart rate than that of controlsubjects (65±4·2 beats min^?1). HRV_ts at highfrequencies was greater for trained men (5·98±0·22) than for untrainedmen (5·23±0·32). These data suggest that regular aerobic exercise inolder men is associated with greater levels of HRV_ts at rest.     

Effects of load and type of physical training on resting and postexercise cardiac autonomic control

The aim of the study was to investigate the influence of training load and exercise mode on heart rate variability and heart rate recovery (HRR) in healthy individuals. The subjects were divided into three groups: sedentary (SED), resistance trained (RT) and aerobically trained (RT). Resting and postmaximal exercise RR intervals were recorded on supine and seated position, respectively. The HRV indices calculated in the resting position were RMSSD and LF and HF power densities. The following HRR indices were calculated throughout the 5‐minute postmaximal recovery period: semi‐logarithmic regression analysis of the first 30 s (T30); absolute difference between the peak and 60 s HR (HRR_60s); and mono‐exponential time constant of HRR (HRRτ). The RMSSD on subsequent 30‐s segments (RMSSD_30s) on recovery period was also calculated. Both RT and AT groups presented faster HRR than SED (P<0·05). The aerobic trained group was the only group that presented vagal reactivation, when analysing the RMSSD_30s. There were no correlations between the Baecke sport score and the HRV vagal‐related indices. However, it was significantly correlated with HRR. It was concluded that that the training load positively influences the HRR, but has no effect on the HRV at rest and that the type of exercise, showed a marked influence on HRV recovery.     

Can geometric indices of heart rate variability predict improvement in autonomic modulation after resistance training in chronic obstructive pulmonary disease?

Chronic obstructive pulmonary disease (COPD) is associated with autonomic dysfunctions that can be evaluated through heart rate variability (HRV). Resistance training promotes improvement in autonomic modulation; however, studies that evaluate this scenario using geometric indices, which include nonlinear evaluation, thus providing more accurate information for physiological interpretation of HRV, are unknown. This study aimed to investigate the influence of resistance training on autonomic modulation, using geometric indices of HRV, and peripheral muscle strength in individuals with COPD. Fourteen volunteers with COPD were submitted to resistance training consisting of 24 sessions lasting 60 min each, with a frequency of three times a week. The intensity was determined as 60% of one maximum repetition and was progressively increased until 80% for the upper and lower limbs. The HRV and dynamometry were performed at two moments, the beginning and the end of the experimental protocol. Significant increases were observed in the RRtri (4·81 ± 1·60 versus 6·55 ± 2·69, P = 0·033), TINN (65·36 ± 35·49 versus 101·07 ± 63·34, P = 0·028), SD1 (7·48 ± 3·17 versus 11·04 ± 6·45, P = 0·038) and SD2 (22·30 ± 8·56 versus 32·92 ± 18·78, P = 0·022) indices after the resistance training. Visual analysis of the Poincare plot demonstrated greater dispersion beat-to-beat and in the long-term interval between consecutive heart beats. Regarding muscle strength, there was a significant increase in the shoulder abduction and knee flexion. In conclusion, geometric indices of HRV can predict improvement in autonomic modulation after resistance training in individuals with COPD; improvement in peripheral muscle strength in patients with COPD was also observed.     

Circulatory response to single circuit weight and walking training sessions of similar energy cost in middle‐aged overweight females

The aim of this study was to compare circulatory responses to circuit weight (CWT) and aerobic walking training sessions of similar energy cost in middle‐aged overweight females. Thirty‐three middle‐aged pre‐menopausal females participated in the experiment. They were divided into overweight (n=18, 36·2 ± 6·3 years, 166·3 ± 8·0 cm, 83·5 ± 9·7 kg, BMI 30·2 ± 3·1 kg m^–2) and non‐overweight control (n=15, 34·1 ± 6·3 years, 165·0 ± 5·6 cm, 61·6 ± 5·0 kg, BMI 22·7 ± 1·5 kg m^–2) groups. Individual physical working capacity (PWC) was measured using the cycle ergometer test (calculated at the level of predicted HR_max (205 – ½ age). A CWT session consisted of leg extension, bench press, sit‐ups and leg press exercises. The subjects performed four circuits at the maximal possible speed, using a work‐to‐rest ratio of 60 s. Blood pressure (BP) was measured during every rest period between the exercises, and the heart rate (HR) was recorded continuously during the whole CWT programme. During the walking training session, the subjects walked as fast as possible on the indoor track. The total energy cost of the walking training session was the same as during the CWT session, approximately 270 kcal, and was controlled by a CALTRAC accelerometer. HR and BP were measured every 5 min during the walking training session. The PWC index was significantly (P<0·05) higher in the overweight group in comparison with the control females (215·4 ± 76·1 and 187·9 ± 42·4 W, respectively). The resting BP was normal in both groups (<140/90 mmHg). HR was between 120 and 140 beats min^–1 during CWT and walking sessions. There were no differences in BP during both training sessions in overweight and control subjects. It was concluded that both CWT and walking training sessions were acceptable forms of physical activity to increase cardiovascular fitness in middle‐aged overweight and normal body weight females.