Mariem Labidi1,2, Mohammed Ihsan1,3, Fearghal P Behan1,4, Marine Alhammoud5, Tessa Smith6, Mohamed Mohamed6, Claire Tourny2, Sébastien Racinais7. 1. Research and Scientific Support Department, Aspetar Orthopaedic and Sports Medicine Hospital, PO Box 29222, Doha, Qatar. 2. Faculty of Sport Sciences and Physical Education, CETAPS, University of Rouen, Mont-Saint-Aignan, France. 3. Human Potential and Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Republic of Singapore. 4. School of Health and Human Performance, Dublin City University, Dublin, Ireland. 5. Surgery Department, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Qatar. 6. Radiology Department, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Qatar. 7. Research and Scientific Support Department, Aspetar Orthopaedic and Sports Medicine Hospital, PO Box 29222, Doha, Qatar. sebastien.racinais@aspetar.com.
Abstract
PURPOSE: Animal and human studies have shown that repeated heating may induce skeletal muscle adaptations, increasing muscle strength. The aim of this study is to investigate the effect of 6 weeks of localized heating on skeletal muscle strength, volume and contractile properties in healthy humans. METHODS: Fifteen active participants (8 males/7 females, 35 ± 6 years, 70 ± 14 kg, 173 ± 7 cm, average training of 87 min per week) were subjected to 6 weeks of single-leg heat therapy. Heat pads were applied for 8 h/day, 5 days/week, on one randomly selected calf of each participant, while the contralateral leg acted as control. The heat pads increased muscle temperature by 4.6 ± 1.2 °C (p < 0.001). Every 2 weeks, participants were tested for morphological (MRI), architectural (ultrasound), contractile (electrically evoked twitch), and force (isometric and isokinetic) adaptations. RESULTS: Repeated localized heating did not affect the cross-sectional area (p = 0.873) or pennation angle (p = 0.345) of the gastrocnemius muscles; did not change the evoked peak twitch amplitude (p = 0.574) or rate of torque development (p = 0.770) of the plantar flexors; and did not change maximal voluntary isometric (p = 0.214) or isokinetic (p = 0.973) plantar flexor torque. CONCLUSION: Whereas previous studies have observed improved skeletal muscle function following whole-body and localized heating in active and immobilized humans, respectively, the current data suggested that localized heating may not be a potent stimulus for muscle adaptations in active humans.
PURPOSE: Animal and human studies have shown that repeated heating may induce skeletal muscle adaptations, increasing muscle strength. The aim of this study is to investigate the effect of 6 weeks of localized heating on skeletal muscle strength, volume and contractile properties in healthy humans. METHODS: Fifteen active participants (8 males/7 females, 35 ± 6 years, 70 ± 14 kg, 173 ± 7 cm, average training of 87 min per week) were subjected to 6 weeks of single-leg heat therapy. Heat pads were applied for 8 h/day, 5 days/week, on one randomly selected calf of each participant, while the contralateral leg acted as control. The heat pads increased muscle temperature by 4.6 ± 1.2 °C (p < 0.001). Every 2 weeks, participants were tested for morphological (MRI), architectural (ultrasound), contractile (electrically evoked twitch), and force (isometric and isokinetic) adaptations. RESULTS: Repeated localized heating did not affect the cross-sectional area (p = 0.873) or pennation angle (p = 0.345) of the gastrocnemius muscles; did not change the evoked peak twitch amplitude (p = 0.574) or rate of torque development (p = 0.770) of the plantar flexors; and did not change maximal voluntary isometric (p = 0.214) or isokinetic (p = 0.973) plantar flexor torque. CONCLUSION: Whereas previous studies have observed improved skeletal muscle function following whole-body and localized heating in active and immobilized humans, respectively, the current data suggested that localized heating may not be a potent stimulus for muscle adaptations in active humans.
Entities:
Keywords:
Force; Heat stress; Human skeletal muscle; Hypertrophy; Isokinetic
Authors: K Goto; R Okuyama; H Sugiyama; M Honda; T Kobayashi; K Uehara; T Akema; T Sugiura; S Yamada; Y Ohira; T Yoshioka Journal: Pflugers Arch Date: 2003-10-08 Impact factor: 3.657
Authors: Vienna E Brunt; Matthew J Howard; Michael A Francisco; Brett R Ely; Christopher T Minson Journal: J Physiol Date: 2016-06-30 Impact factor: 5.182