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- Helland, Christian, et al.
(författare)
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Training Strategies to Improve Muscle Power : Is Olympic-style Weightlifting Relevant?
- 2017
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Ingår i: Medicine & Science in Sports & Exercise. - Philadelphia, PA : Lippincott Williams & Wilkins. - 0195-9131 .- 1530-0315. ; 49:4, s. 736-745
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: This efficacy study investigated the effects of (1) Olympic-style weightlifting (OWL), (2) motorized strength and power training (MSPT), and (3) free weight strength and power training (FSPT) on muscle power.METHODS: Thirty-nine young athletes (20±3 yr.; ice hockey, volleyball and badminton) were randomized into the three training groups. All groups participated in 2-3 sessions/week for 8 weeks. The MSPT and FSPT groups trained using squats (two legs and single leg) with high force and high power, while the OWL group trained using clean and snatch exercises. MSPT was conducted as slow-speed isokinetic strength training and isotonic power training with augmented eccentric load, controlled by a computerized robotic engine system. FSPT used free weights. The training volume (sum of repetitions x kg) was similar between all three groups. Vertical jumping capabilities were assessed by countermovement jump (CMJ), squat jump (SJ), drop jump (DJ), and loaded CMJs (10-80 kg). Sprinting capacity was assessed in a 30 m sprint. Secondary variables were squat 1-repetition-maximum, body composition and quadriceps thickness and architecture.RESULTS: OWL resulted in trivial improvements, and inferior gains compared to FSPT and MSPT for CMJ, SJ, and DJ. MSPT demonstrated small, but robust effects on SJ, DJ and loaded CMJs (3-12%). MSPT was superior to FSPT in improving 30 m sprint performance. FSPT and MSPT, but not OWL, demonstrated increased thickness in the vastus lateralis and rectus femoris (4-7%).CONCLUSION: MSPT was time-efficient and equally or more effective than FSPT training in improving vertical jumping and sprinting performance. OWL was generally ineffective and inferior to the two other interventions. Copyright © 2016 by the American College of Sports Medicine.
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| 2. |
- Horwath, Oscar, et al.
(författare)
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Isokinetic resistance training combined with eccentric overload improves athletic performance and induces muscle hypertrophy in young ice hockey players.
- 2019
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Ingår i: Journal of Science and Medicine in Sport. - Chatswood : Elsevier. - 1440-2440 .- 1878-1861. ; 22:7, s. 821-826
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: To determine the combined effects of slow isokinetic resistance training and eccentric overload and compare it to traditional resistance training on strength, power, body composition and muscle hypertrophy in young ice hockey players.DESIGN: Experimental, randomized trial.METHODS: Twenty-two resistance-trained ice hockey players (18±1year) were assigned to either isokinetic resistance training and eccentric overload (ISO/ECC; n=11) or traditional resistance training (TRAD; n=11). Participants underwent supervised progressive resistance training for 8 weeks (2-3 sessions/week) involving lower body multiple-joint exercises (heavy squats and explosive jump squats). The ISO/ECC group performed their training using a computerized robotic engine system (1080 Quantum synchro, Sweden), whereas the TRAD group performed the same resistance exercises with isotonic loading. Before and after the intervention, participants were evaluated in 1RM back squat, loaded jump squats, sprint- and jump performance, body composition and muscle thickness using ultrasound measurement.RESULTS: Similar moderate increases in 1RM back squat and power output in the jump squats were found in both the ISO/ECC and TRAD groups (11-17%, P<0.01), whereas only the ISO/ECC group showed improvements in drop jump performance (9.8%, P=0.01). Moreover, similar trivial changes in body composition were observed in both groups, while only the ISO/ECC training group increased muscle thickness in the vastus intermedius (P=0.01) and rectus femoris muscles (P=0.03).CONCLUSIONS: Both modalities effectively increased maximal strength and power output, whereas isokinetic resistance training, combined with eccentric overload, improved drop jump performance and induced greater muscle hypertrophy than traditional training in young ice hockey players. © 2019 Sports Medicine Australia
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| 3. |
- Seynnes, Olivier R, et al.
(författare)
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Ultrasound-Based Testing Of Tendon Mechanical Properties : A Critical Evaluation.
- 2015
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Ingår i: Journal of applied physiology. - : American Physiological Society. - 8750-7587 .- 1522-1601. ; 118:2, s. 133-141
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Tidskriftsartikel (refereegranskat)abstract
- In the past twenty years, the use of ultrasound-based methods has become a standard approach to measure tendon mechanical properties in vivo. Yet, the multitude of methodological approaches adopted by various research groups probably contributes to the large variability of reported values. The technique of obtaining and relating tendon deformation to tensile force in vivo has been applied differently, depending on practical constraints or scientific points of view. Divergence can be seen in i) methodological considerations such as the choice of anatomical features to scan and to track, force measurements or signal synchronisation and ii), in physiological considerations related to the viscoelastic behaviour or length measurements of tendons. Hence, the purpose of the present review is to assess and discuss the physiological and technical aspects connected to in vivo testing of tendon mechanical properties. In doing so, our aim is to provide the reader with a systematic, qualitative analysis of ultrasound-based techniques. Finally, a list of recommendations is proposed for a number of selected issues.
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