The effects of water-based circuit exercise training on vascular function in people with coronary heart disease.

Impaired endothelial function in people with coronary heart disease (CHD) is associated with increased mortality. Water immersion can increase peripheral artery shear stress which may provide an additional stimulus to the endothelium during exercise. This study compared the effects of water-based circuit exercise training (WEX) and gym-based circuit exercise training (GEX) on vascular function in people with stable CHD. Participants were randomized to 12 wk of WEX (n = 20), GEX (n = 20), or a control group (usual activities; n = 12). Endothelium-dependent flow-mediated dilation (FMD) and glyceryl trinitrate-mediated dilation (GTN) of the brachial artery were assessed pre- and postintervention. FMD increased following WEX [4.0% (3.0%-5.1%) to 5.3% (4.1%-6.5%); P = 0.016], but was unchanged following GEX [4.9% (3.8%-5.9%) to 5.0% (3.8%-6.1%); P = 0.822]. There were no between-group differences in the change in FMD and no significant changes in GTN-mediated dilation percentage. Triglycerides decreased following GEX [1.2 mmol·L-1 (1.0-1.4 mmol·L-1) to 1.0 mmol·L-1 (0.8-1.3 mmol·L-1); P = 0.022], but there were no further differences in lipid profiles. WEX improved endothelial function of the brachial artery in people with stable CHD, suggesting that WEX is an effective alternative to gym-based exercise in people living with CHD, which may specifically address vascular health.NEW & NOTEWORTHY This study found that 12 wk of water-based circuit exercise training was well tolerated and improved vascular endothelial function in people with stable coronary heart disease. However, there was no effect on endothelium-independent function. Water-based exercise appears to be an effective alternative to gym-based exercise for people with coronary heart disease, which has specific benefits to vascular health and function.

Testosterone and exercise: effects on fitness, body composition, and strength in middle-to-older aged men with low-normal serum testosterone levels.

As men age, serum testosterone (T) concentrations decrease, as do fitness, strength, and lean mass. Whether testosterone treatment confers additive benefit to reverse these changes when combined with exercise training in middle-to-older aged men remains unclear. We assessed the effects of T treatment and exercise, alone and in combination, on aerobic capacity (V̇o2peak), body composition, and muscular strength in men 50-70 yr, waist circumference ≥95 cm and low-normal serum T (6-14 nmol·L-1). Participants (n = 80) were randomized to AndroForte5 (testosterone 5.0% wt/vol, 100 mg/2 mL) cream (T), or matching placebo (P), applied transdermally daily, and supervised center-based exercise (Ex) or no additional exercise (NEx), for 12-wk. Exercise increased V̇o2peak and strength versus nonexercise (V̇o2peak: T + Ex: +2.5 mL·kg-1·min-1, P + Ex: +3.2 mL·kg-1·min-1, P < 0.001; leg press: T + Ex: +31 kg, P + Ex: +24 kg, P = 0.006). T treatment did not affect V̇o2peak or strength. Exercise decreased total (T + Ex: -1.7, P + Ex: -2.3 kg, P < 0.001) and visceral fat (T + Ex: -0.1 kg, P + Ex: -0.3 kg, P = 0.003), and increased total (T + Ex: +1.4 kg, P + Ex: +0.7 kg, P = 0.008) and arm lean mass (T + Ex: +0.5 kg, P + Ex: +0.3 kg, P = 0.024). T treatment did not affect total or visceral fat, but increased total (T + Ex: +1.4 kg, T + NEx: +0.7 kg, P = 0.015), leg (T + Ex: +0.3 kg, T + NEx: +0.2 kg, P = 0.024), and arm lean mass (T + Ex: +0.5 kg, T + NEx: +0.2 kg, P = 0.046). T + Ex increased arm lean mass (T + Ex: +0.5 kg vs. P + NEx: -0.0 kg, P = 0.001) and leg strength (T + Ex: +31 kg vs. P + NEx: +12 kg, P = 0.032) compared with P + NEx, with no other additive effects. Exercise training was more effective than T treatment in increasing aerobic capacity and decreasing total and visceral fat mass. T treatment at therapeutic doses increased lean mass but conferred limited additional benefit when combined with exercise. Exercise should be evaluated as an antiaging intervention in preference to testosterone treatment in men.NEW & NOTEWORTHY We illustrate that exercise training generates superior outcomes to testosterone treatment for improving aerobic fitness, muscular strength, and total and visceral fat mass in men 50-70 yr with low-normal serum testosterone concentrations. Adding testosterone treatment to exercise did not provide any additive benefit for these variables. Testosterone treatment alone and exercise alone had similar impacts on lean mass. Therefore, men unable to exercise may obtain benefit from testosterone treatment alone to improve lean mass.

Effects of testosterone treatment, with and without exercise training, on ambulatory blood pressure in middle-aged and older men.

CONTEXT: With age, testosterone (T) and physical activity levels often decline in parallel. The effect of combining T treatment and exercise training on ambulatory blood pressure (ABP) is unclear. OBJECTIVE: To assess T and exercise effects, alone and in combination, on ABP in men aged 50-70 years, waist circumference ≥ 95 cm and low-normal serum T (6-14 nmol/L), without organic hypogonadism. DESIGN: A 2 × 2 factorial randomised, placebo-controlled study. INTERVENTION: Randomization to daily transdermal AndroForte5® (Testosterone 5.0%w/v, 100 mg in 2 ml) cream (T), or matching placebo (P) (double-blind), and to supervised exercise (Ex) or no additional exercise (NEx), for 12 weeks. RESULTS: Average 24-h systolic blood pressure (SBP) increased with T treatment (testosterone*time, p = .035). Average 24-h SBP increased in T+Ex (T+Ex:+3.0 vs. P+NEx: -3.0 mmHg, p = .026) driven by day-time changes (T+Ex:+3.5 vs. P+NEx: -3.0 mmHg, p = .026). There was an effect of T for 24-h average diastolic blood pressure (DBP, testosterone*time, p = .044) driven by the decrease in P+Ex (P+Ex: -3.9 vs. T+NEx: -0.5 mmHg, p = .015). Night-time DBP was lower with exercise (P+Ex: -4.0 vs. P+NEx: +0.7 mmHg, p = .032). The effect of exercise to lower night-time DBP was not apparent in the presence of T (T+Ex: -0.4 vs. P+NEx: +0.7 mmHg, p > .05). Ex increased average 24-h pulse pressure (PP, exercise*time, p = .022), largely during daytime hours (exercise*time, p = .013). CONCLUSIONS: There was a main effect of T to increase 24-h SBP, primarily seen when T was combined with Ex. Exercise alone decreased 24-h and night-time DBP; an effect attenuated by T. BP should be carefully assessed and monitored, when prescribing T treatment to middle-aged and older men, especially when combined with exercise training.

Higher circulating androgens and higher physical activity levels are associated with less central adiposity and lower risk of cardiovascular death in older men.

OBJECTIVE: Low endogenous sex hormones and low physical activity (PA) levels have been associated with CVD risk. Whether these interact to influence CVD outcomes remains unclear. We assessed whether sex hormone concentrations and PA were additively associated with lower central adiposity and CVD risk. PATIENTS: 3351 community-dwelling men, mean age 77 years. MEASUREMENTS: Baseline testosterone (T), dihydrotestosterone (DHT) and oestradiol (E2) were assayed. Levels of PA were ascertained by questionnaire. Men were stratified using median splits into high hormone + high PA (H/H), high hormone + low PA (H/L); low hormone + high PA (L/H) and low hormone + low PA (L/L) groups. RESULTS: A total of 865 CVD events and 499 CVD deaths occurred during 10-year mean follow-up. Men with higher T, DHT or SHBG and higher PA had the lowest BMI, waist circumference and risk of metabolic syndrome. Men with higher T had the lowest risk of incident CVD events, irrespective of PA level. Men with higher T or DHT and higher PA had the lowest risk of dying from CVD (eg, hazard ratios for T/PA H/H 0.76 P = 0.031; H/L 0.85 P = 0.222; L/H 0.80 P = 0.075; L/L 1.00). CONCLUSION: Higher circulating androgens and higher PA were associated with less central adiposity at baseline and fewer CVD deaths during follow-up. These findings are consistent with a potential additive effect of androgens and PA on cardiometabolic outcomes in older men.

Greater physical activity and higher androgen concentrations are independently associated with lower cardiometabolic risk in men.

CONTEXT: Male ageing is associated with lower circulating testosterone (T) and increased incidence of cardiovascular disease (CVD). Whether physical activity (PA) interacts with hormones to modify CVD risk is unclear. OBJECTIVE: We assessed whether PA and sex hormone concentrations were independently associated with measures of CVD risk. PARTICIPANTS: A total of 1649 men. METHODS: Leisure, home, work and total PA were ascertained. At baseline, serum T, dihydrotestosterone (DHT) and oestradiol (E2) were assayed. Men were stratified into high PA+high hormone (H/H); low PA+high hormone (L/H); high PA+low hormone (H/L); and low PA+low hormone (L/L). RESULTS: Mean age was 49.8 years at outset with 415 CVD events and 127 CVD deaths occurring during 20-year follow-up. Men with higher PA and higher T or DHT had lower odds of metabolic syndrome (eg leisure H/H vs L/L odds ratio [OR] 0.17 P<.001 for T, 0.26 P<.001 for DHT). Men with higher PA and E2 had lower risk of metabolic syndrome (eg leisure PA H/H vs L/L OR 0.51, P=.001). Men with higher leisure, work or total PA and higher DHT had the lowest risk of CVD death (eg leisure H/H hazard ratio [HR] 0.55 vs L/L, P=.033). Men with lower leisure, home or work PA and higher E2 were at greater risk of CVD death (eg leisure L/H HR 1.60 vs L/L, P=.039). CONCLUSIONS: Considering T, DHT and E2 in the context of PA better informs consideration of cardiovascular risk. A 2×2 factorial RCT assessing PA and androgens would illuminate the scope for preventing CVD in men.

Comparing the Impacts of Testosterone and Exercise on Lean Body Mass, Strength and Aerobic Fitness in Aging Men.

BACKGROUND: Based on the largely untested premise that it is a restorative hormone that may reverse the detrimental impacts of aging, prescription of testosterone (T) has increased in recent decades despite no new clinical indications. It is apparent that middle-aged and older men with low-normal serum T levels are considering T supplementation as an anti-aging strategy. At the same time, there is evidence that physical activity (PA) is at historical lows in the Western world. In this review, we compare the impacts of T treatment aimed at achieving physiological T concentrations in middle-aged and older men, alongside the impacts of ecologically relevant forms of exercise training. The independent, and possible combined, effects of T and exercise therapy on physiological outcomes such as aerobic fitness, body composition and muscular strength are addressed. MAIN BODY: Our findings suggest that both T treatment and exercise improve lean body mass in healthy older men. If improvement in lean body mass is the primary aim, then T treatment could be considered, and the combination of T and exercise may be more beneficial than either in isolation. In terms of muscle strength in older age, an exercise program is likely to be more beneficial than T treatment (where the dose is aimed at achieving physiological concentrations), and the addition of such T treatment does not provide further benefit beyond that of exercise alone. For aerobic fitness, T at doses aimed at achieving physiological concentrations has relatively modest impacts, particularly in comparison to exercise training, and there is limited evidence as to additive effects. Whilst higher doses of T, particularly by intramuscular injection, may have larger impacts on lean body mass and strength, this must be balanced against potential risks. CONCLUSION: Knowing the impacts of T treatment and exercise on variables such as body composition, strength and aerobic fitness extends our understanding of the relative benefits of physiological and pharmacological interventions in aging men. Our review suggests that T has impacts on strength, body composition and aerobic fitness outcomes that are dependent upon dose, route of administration, and formulation. T treatment aimed at achieving physiological T concentrations in middle-aged and older men can improve lean body mass, whilst exercise training enhances lean body mass, aerobic fitness and strength. Men who are physically able to exercise safely should be encouraged to do so, not only in terms of building lean body mass, strength and aerobic fitness, but for the myriad health benefits that exercise training confers.

New Horizons: Testosterone or Exercise for Cardiometabolic Health in Older Men.

Middle-aged and older men have typically accumulated comorbidities, are increasingly sedentary, and have lower testosterone concentrations (T) compared to younger men. Reduced physical activity (PA) and lower T both are associated with, and may predispose to, metabolically adverse changes in body composition, which contribute to higher risks of cardiometabolic disease. Exercise improves cardiometabolic health, but sustained participation is problematic. By contrast, rates of T prescription have increased, particularly in middle-aged and older men without organic diseases of the hypothalamus, pituitary, or testes, reflecting the unproven concept of a restorative hormone that preserves health. Two recent large randomized trials of T, and meta-analyses of randomized trials, did not show a signal for adverse cardiovascular (CV) events, and T treatment on a background of lifestyle intervention reduced type 2 diabetes by 40% in men at high risk. Men with both higher endogenous T and higher PA levels have lower CV risk, but causality remains unproven. Exercise training interventions improve blood pressure and endothelial function in middle-aged and older men, without comparable benefits or additive effects of T treatment. Therefore, exercise training improves cardiometabolic health in middle-aged and older men when effectively applied as a supervised regimen incorporating aerobic and resistance modalities. Treatment with T may have indirect cardiometabolic benefits, mediated via favorable changes in body composition. Further evaluation of T as a pharmacological intervention to improve cardiometabolic health in aging men could consider longer treatment durations and combination with targeted exercise programs.

Testosterone and Exercise in Middle-to-Older Aged Men: Combined and Independent Effects on Vascular Function.

[Figure: see text].

Cerebral Blood Flow during Exercise in Heart Failure: Effect of Ventricular Assist Devices.

INTRODUCTION: In healthy individuals, cerebral blood flow (CBF) increases during exercise, but few studies have compared changes in CBF during exercise in patients with heart failure (HF) to healthy controls (CTRL) or assessed the effects of left ventricular assist devices (LVAD). We hypothesized that subjects implanted with LVAD would exhibit impaired cerebrovascular responses to cycle exercise when compared with age- and sex-matched healthy CTRL subjects but would have enhanced responses relative to subjects with HF. METHODS: Internal carotid artery (ICA) blood flow and intracranial middle (MCAv) and posterior cerebral (PCAv) artery velocities were measured continuously using Doppler ultrasound, alongside cardiorespiratory measures at rest and in response to an incremental submaximal cycle ergometer exercise protocol in nine LVAD participants (58 ± 15 yr, 87 ± 16 kg, 172 ± 8 cm, six females), nine age- and sex-matched subjects with HF (58 ± 8 yr, 84 ± 11 kg, 177 ± 6 cm), and nine CTRL (55 ± 14 yr, 74 ± 16 kg, 168 ± 10 cm). RESULTS: At rest, ICA hemodynamics (velocity, shear rate, and flow) were greater in CTRL and LVAD than that in HF (P < 0.05). Higher MCAv (+5.52 ± 1.59 cm·s, P = 0.003) and PCAv (+5.82 ± 1.41 cm·s, P = 0.001) were also observed in LVAD subjects than healthy CTRL. During exercise, ICA flow increased at all workloads in CTRL, but not in HF or LVAD groups. MCAv increased from baseline in both HF and CTRL participants (P = 0.0001), but not in LVAD subjects. Nonetheless, CTRL and LVAD showed higher MCAv (P = 0.006) and PCAv (P < 0.0001) values throughout exercise than HF. CONCLUSION: Our findings indicate that LVAD subjects exhibit higher CBF at rest and during exercise than matched HF participants but attenuated brain blood flows during exercise when compared with healthy subjects. CBF should be considered when designing exercise training interventions in patients with HF and LVAD.

Eccentric Cycling: A Promising Modality for Patients with Chronic Heart Failure.

PURPOSE: Chronic heart failure (CHF) is characterized by dyspnea and poor exercise tolerance, which decreases aerobic capacity (V˙O2peak), a measure strongly correlated with quality of life and mortality. In healthy populations, eccentric (ECC) cycling can be performed at a lower oxygen demand for matched workload, compared with concentric (CON) cycling, but few studies have previously investigated ECC cycling in CHF. We hypothesized that, when matched for external workload (W), an ECC cycling bout would be performed at a lower cardiorespiratory load (V˙O2) than CON in patients with CHF. METHODS: Eleven CHF patients (10 males) with impaired left ventricular systolic function (ejection fraction 31% ± 12%) completed a CON V˙O2peak test, with the subsequent ECC and CON protocols set at 70% of individual maximal CON power (W). Oxygen consumption (V˙O2), RER, minute ventilation (V˙E), HR, and rate pressure product were compared between conditions. RESULTS: ECC was performed at a lower V˙O2 (12.3 ± 1.3 vs 14.1 ± 0.8 mL·kg·min, P = 0.01), RER (0.92 ± 0.02 vs 0.96 ± 0.01, P = 0.01), and V˙E (36.5 ± 4.4 vs 40.2 ± 2.0 L·min, P = 0.04) in comparison with CON, despite both conditions being performed at matched workloads. HR (101 ± 5 vs 96 ± 1 bpm, P = 0.06) and rate pressure product (13,539 ± 788 vs 11,911 ± 227 bpm·mm Hg, P = 0.15) were not significantly different between conditions. CONCLUSION: When matched for external workload, ECC cycling can be performed with a lower oxygen demand than CON in patients with CHF. Eccentric cycling is a promising modality for cardiac rehabilitation in severely deconditioned patients with CHF.

Acute impact of conventional and eccentric cycling on platelet and vascular function in patients with chronic heart failure.

Evidence-based guidelines recommend exercise therapy for patients with chronic heart failure (CHF). Such patients have increased atherothrombotic risk. Exercise can transiently increase platelet activation and reactivity and decrease vascular function in healthy participants, although data in CHF are scant. Eccentric (ECC) cycling is a novel exercise modality that may be particularly suited to patients with CHF, but the acute impacts of ECC cycling on platelet and vascular function are currently unknown. Our null hypothesis was that ECC and concentric (CON) cycling, performed at matched external workloads, would not induce changes in platelet or vascular function in patients with CHF. Eleven patients with heart failure with reduced ejection fraction (HFrEF) took part in discrete bouts of ECC and CON cycling. Before and immediately after exercise, vascular function was assessed by measuring diameter and flow-mediated dilation (FMD) of the brachial artery. Platelet function was measured by the flow cytometric determination of glycoprotein IIb/IIIa activation and granule exocytosis in the presence and absence of platelet agonists. ECC cycling increased baseline artery diameter (pre: 4.0 ± 0.8 mm vs. post: 4.2 ± 0.7 mm; P = 0.04) and decreased FMD%. When changes in baseline artery diameter were accounted for, the decrease in FMD post-ECC cycling was no longer significant. No changes were apparent after CON. Neither ECC nor CON cycling resulted in changes to any platelet-function measures (all P > 0.05). These results suggest that both ECC and CON cycling, at a moderate intensity and short duration, can be performed by patients with HFrEF without detrimental impacts on vascular or platelet function.NEW & NOTEWORTHY This is the first evidence to indicate that eccentric (ECC) cycling can be performed relatively safely by patients with chronic heart failure (CHF), as it did not result in impaired vascular or platelet function compared with conventional cycling. This is important, as acute exercise can transiently increase atherothrombotic risk, and ECC cycling is a novel exercise modality that may be particularly suited to patients with CHF.