Seven months of aerobic intradialytic exercise training can prevent muscle loss in haemodialysis patients: an ultrasonography study.

PURPOSE: This study aimed to evaluate the effects of 7-month intradialytic exercise training (IDE) on vastus lateralis (VL) muscle architecture, functional capacity and quality of life in stable haemodialysis (HD) patients. METHODS: 44 HD patients were randomly assigned into an Exercise Group (EG = 21), which they received 7 months of IET, at 60% of pre-assessed maximum aerobic power, 3/week) or into a Control Group (CG = 23, no exercise). VL architecture was evaluated with ultrasonography, functional capacity was assessed using a series of functional tests (6 min walking test, 5 repetitions sit-to-stand, sit-to-stand 60 s, handgrip strength), and maximal aerobic power determined with a modified version of the Åstrand test. Quality of life and fatigue levels were evaluated using validated questionnaires. RESULTS: VL fascicle angle and length did not change significantly in both groups (P > 0.05). Muscle thickness decreased in CG (P = 0.02) while it was fully preserved in the EG. Functional capacity increased only in the EG (6 min walking test 15.79 ± 12.35%, P < 0.001; max aerobic power 26.36 ± 1.24%, P < 0.001; STS-60rep: 10.23 ± 1.60%, P < 0.000; hand grip strength: 5.14 ± 28.30%, P < 0.02). CONCLUSION: Intradialytic aerobic exercise training, improves functional capacity and prevents thigh muscle mass loss in HD patients. It is evident that muscle ultrasonography could play a pivotal role in assessing muscle quality changes in haemodialysis patients. A higher level of training intensity or combination with resistance exercises may be required to further improve anabolism and influence muscle architecture in this patient population. CLINICAL TRIAL REGISTRY NUMBER: NCT03905551.

The Acute Impact of Different Types of Aerobic Exercise on Arterial Wave Reflections and Inflammation.

OBJECTIVES: Whilst physical activity is linked to cardiovascular health, it has lately been recognized that different types of exercise exert diverse effects on the cardiovascular system. Therefore, we investigated the acute effects of continuous moderate-intensity aerobic exercise (CAE) and high-intensity interval aerobic exercise (hIAE) on arterial function and inflammation. METHODS: Twenty healthy men (mean age 22.6 ± 3.3 years) were recruited in this crossover study. Each of the 20 volunteers participated in two separate sessions (hIAE and CAE). The augmentation index (AIx) of aortic pressure waveforms and serum levels of interleukin-17 (IL-17) were measured before and after each exercise session. RESULTS: There were no significant differences in baseline hemodynamic and inflammatory measurements before CAE and hIAE. Compared to baseline, AIx was significantly improved after CAE (p = 0.04), while there was no significant change after hIAE (p = 0.65). Serum levels of IL-17 were significantly elevated after CAE (p = 0.042), while hIAE had no significant effect on IL-17 levels (p = 0.47). Interestingly, there was an inverse association between the elevation of IL-17 levels and the AIx improvement after CAE (p = 0.05). CONCLUSION: These findings provide additional evidence concerning the cardiovascular effects of different types of exercise training through modification of peripheral hemodynamics and the inflammatory process.

Acute effects of different types of aerobic exercise on endothelial function and arterial stiffness.

BACKGROUND: Chronic aerobic exercise training is associated with improved endothelial function and arterial stiffness and favourable long-term cardiovascular effects. DESIGN: We investigated the acute effects of continuous moderate intensity aerobic exercise (CAE) and high intensity interval aerobic exercise (hIAE) on endothelial function and arterial stiffness in healthy participants. METHODS: Twenty healthy men were recruited to this cross-over study. They participated in two exercise sessions: (a) CAE, volume at 50% of maximum aerobic work for 30 minutes; and (b) hIAE, interval maximum aerobic work for 30 minutes. Endothelial function was evaluated by flow-mediated dilation in the brachial artery. The carotid femoral pulse wave velocity and the femoral dorsalis pedis pulse wave velocity were measured as indices of central aortic and peripheral arterial stiffness. Measurements were carried out before and immediately after each exercise session. RESULTS: There was no statistically significant difference in the baseline measurements before CAE and hIAE with respect to flow-mediated dilation, the carotid femoral pulse wave velocity and the femoral dorsalis pedis pulse wave velocity (p = NS). Both CAE and hIAE significantly improved the flow-mediated dilation compared with baseline (p < 0.001). Similarly, the femoral dorsalis pedis pulse wave velocity was improved after CAE and hIAE (p < 0.005), whereas the carotid femoral pulse wave velocity was not significantly affected (p = NS). CONCLUSION: Both CAE and hIAE can favourably affect endothelial function, suggesting another cardioprotective effect of acute exercise. These types of aerobic exercise have a different impact on the central and peripheral arterial stiffness.

Effects of Strength vs. Ballistic-Power Training on Throwing Performance.

The purpose of the present study was to investigate the effects of 6 weeks strength vs. ballistic-power (Power) training on shot put throwing performance in novice throwers. Seventeen novice male shot-put throwers were divided into Strength (N = 9) and Power (n = 8) groups. The following measurements were performed before and after the training period: shot put throws, jumping performance (CMJ), Wingate anaerobic performance, 1RM strength, ballistic throws and evaluation of architectural and morphological characteristics of vastus lateralis. Throwing performance increased significantly but similarly after Strength and Power training (7.0-13.5% vs. 6.0-11.5%, respectively). Muscular strength in leg press increased more after Strength than after Power training (43% vs. 21%, respectively), while Power training induced an 8.5% increase in CMJ performance and 9.0 - 25.8% in ballistic throws. Peak power during the Wingate test increased similarly after Strength and Power training. Muscle thickness increased only after Strength training (10%, p < 0.05). Muscle fibre Cross Sectional Area (fCSA) increased in all fibre types after Strength training by 19-26% (p < 0.05), while only type IIx fibres hypertrophied significantly after Power training. Type IIx fibres (%) decreased after Strength but not after Power training. These results suggest that shot put throwing performance can be increased similarly after six weeks of either strength or ballistic power training in novice throwers, but with dissimilar muscular adaptations. Key pointsBallistic-power training with 30% of 1RM is equally effective in increasing shot put performance as strength training, in novice throwers, during a short training cycle of six weeks.In novice shot putters with relatively low initial muscle strength/mass, short-term strength training might be more important since it can increase both muscle strength and shot put performance.The ballistic type of power training resulted in a significant increase of the mass of type IIx muscle fibres and no change in their proportion. Thus, this type of training might be used effectively during the last weeks before competition, when the strength training load is usually reduced, in order to increase muscle power and shot put performance in novice shot putters.