The physiological and biomechanical bases of muscular hypertrophy/ atrophy

Introduction: The aims of the current investigations were to modulate muscle-tendon complex (MTC - vastus lateralis [VL] & patella tendon [PT]) adaptations through mechanical stress and strain. Groups performed resistance training (8 weeks) with the MTC placed in a shortened (SL) or a lengthened position (LL) with internal loading standardised. A third group trained over an entire ROM (LX) with the external loading matched to that in SL. MTC response to detraining (4 weeks) was also measured. A control, untrained group was measured during this 12-week period. Methods: Measurements using ultrasonography, dynamometry, electromyography and dual energy absorptiometry were made at baseline (week 0), post-training (week 8), detraining 1 (week 10) and detaining 2 (week 12). VL measurements included volume, cross-sectional area (CSA), and architecture. PT properties included stiffness and Young’s Modulus. Quadriceps MTC function was measured by isometric maximal voluntary contractions (MVC) over a range of joint –angles. Circulating levels of a growth factor (IGF-I) and cytokines (TGF-β1, TNF-α) were measured using enzyme-linked immuno-sorbant assay. Main Results: VL volume, CSA, fascicle length, PT stiffness, modulus, quadriceps MVCs and IGF-I (LL only) were significantly greater (p<0.05) in both LL and LX groups compared to SL post-training. During detraining, CSA, fascicle length, stiffness, modulus, IGF-I (LL only) remained significantly elevated in the LL and LX groups compared to SL. There was no significant change in the control group in any measurement during the study period (p>0.05). Conclusion: Training with the MTC in a lengthened position is more effective for inducing (and retaining) enhanced training MTC adaptations, owing to internal mechanical and physiological stress in this position. This loading method should therefore be incorporated into a structured resistance training program for a range of populations such as athletic, recreationally active, clinical or elderly individuals

"Land without God" : interview with Gerard Mannix Flynn and Maedhbh McMahon

Wywiad z twórcami filmu dokumentalnego pt. "Land without God" (Kraina bez Boga) Gerardem Mannixem Flynnem i Maedhbh McMahon. Film opowiada historię jednej z robotniczych rodzin, której czternastu członków przeszło przez kilka „poprawczaków” i tzw. "szkół przemysłowych", gdzie doświadczyli brutalnego traktowania i wykorzystywanie seksualnego. Wywiad wyjaśnia, w jaki sposób film oddaje głos ocalałym, którzy wreszcie mają szansę opowiedzieć własnymi słowami koszmar, przez który przeszli, i jak systemowa przemoc wpłynęła na ich życie.The interview with the authors of a documentary "Land Without God" Gerard Mannix Flynn, and Maedhbh McMahon, which tells a story of one working-class family whose fourteen members went through several “reform” and industrial schools, where they suffered from brutal treatment and sexual abuse. The interview disucsses how the documentary gives voice to survivors who are finally able to tell in their own words what happened to them, and how the systemic violence has affected their life

Exercise, type 1 diabetes mellitus and blood glucose: The implications of exercise timing

The scientific literature shows that exercise has many benefits for individuals with type 1 diabetes. Yet, several barriers to exercise in this population exist, such as post-exercise hypoglycaemia or hyperglycaemia. Several studies suggest that the timing of exercise may be an important factor in preventing exercise-induced hypoglycaemia or hyperglycaemia. However, there is a paucity of evidence solely focused on summarising findings regarding exercise timing and the impact it has on glucose metabolism in type 1 diabetes. This report suggests that resistance or high-intensity interval exercise/training (often known as HIIT) may be best commenced at the time of day when an individual is most likely to experience a hypoglycaemic event (i.e., afternoon/evening) due to the superior blood glucose stability resistance and HIIT exercise provides. Continuous aerobic-based exercise is advised to be performed in the morning due to circadian elevations in blood glucose at this time, thereby providing added protection against a hypoglycaemic episode. Ultimately, the evidence concerning exercise timing and glycaemic control remains at an embryonic stage. Carefully designed investigations of this nexus are required, which could be harnessed to determine the most effective, and possibly safest, time to exercise for those with type 1 diabetes

Circulating tumor necrosis factor alpha may modulate the short-term detraining induced muscle mass loss following prolonged resistance training

Copyright © 2019 McMahon, Morse, Winwood, Burden and Onambélé. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. Introduction: Tumor necrosis factor alpha (TNFα) is a pro-inflammatory cytokine that has been shown to modulate muscle mass, and is responsive to exercise training. The effects of resistance training (RT) followed by a short period of detraining on muscle size, architecture and function in combination with circulating TNFα levels have not been previously investigated in a young, healthy population. Methods: Sixteen participants (8 males and 8 females) were randomly assigned to a training group (TRA; age 20 ± 3 years, mass 76 ± 7 kg), whilst fourteen participants (7 males and 7 females) age 22 ± 2 years, mass 77 ± 6 kg were assigned to a control group (CON). Measures of vastus lateralis (VL) muscle size (normalized physiological cross-sectional area allometrically scaled to body mass; npCSA), architecture (fascicle length; LF, pennation angle Pθ), strength (knee extensor maximal voluntary contraction; KE MVC), specific force, subcutaneous fat (SF) and circulating TNFα were assessed at baseline (BL), post 8 weeks RT (PT), and at two (DT1) and four (DT2) weeks of detraining. Results: Pooled BL TNFα was 0.87 ± 0.28 pg/mL with no differences between groups. BL TNFα tended to be correlated with npCSA (p = 0.055) and KEMVC (p = 0.085) but not specific force (p = 0.671) or SF (p = 0.995). There were significant (p 0.05) changes in SF, specific force or TNFα at any time points. There was a significant correlation (p = 0.022, r = 0.57) between the relative changes in TNFα and npCSA at DT2 compared to PT. Discussion: Neither RT nor a period of short term detraining altered the quality of muscle (i.e., specific force) despite changes in morphology and function. TNFα does not appear to have any impact on RT-induced gains in muscle size or function, however, TNFα may play a role in inflammatory-status mediated muscle mass loss during subsequent detraining in healthy adults

Monitoring Wellness, Training Load, and Running Performance During a Major International Female Field Hockey Tournament

The current observational study quantified players\u27 activity profiles during a major international female field hockey tournament and determined whether an association exists between well-being measures and running performance within elite female hockey players. Elite female field hockey players (23 6 3 years; 162.6 6 13 cm; and 66 6 6 kg) participated in the study. Participants running performance was monitored using global positioning system technology (S5; Catapult Innovations , Scoresby, Victoria, Australia), with daily well-being questionnaires used to quantify player responses during the tournament. Thresholds for the magnitude of the observed change for each variable were determined using the Hopkins Spreadsheets for analysis of controlled trials. Relative distance (m$min 21) was likely lower when compared with game 1 in game 7. Relative high speed (m$min 21 .16 km$h 21) was likely lower in games 5, 6, and 7 when compared with game 1. Subjective load was very likely higher in game 2 and very likely lower in game 3 when compared with game 1. Mood and sleep quality were likely lower in game 1 when compared with game 4 and game 7. Muscle soreness was likely higher when compared with game 1 in game. During the tournament, it was observed that a decrease in players\u27 daily well-being was accompanied by changes in running performance. Furthermore , changes to players\u27 muscle soreness and sleep quality result in decreased players\u27 high-speed running performance during match-play. Therefore, to prevent the observed effects, coaches should adopt strategies to enhance sleep quality and incorporate specific recovery modalities to reduce musculo-skeletal soreness