Cross-education effect after unilateral eccentric-only isokinetic vs dynamic constant external resistance training

Abstract

The aim of this study was to evaluate the effects of unilateral eccentric training using constant velocity or constant external load on untrained limb. Fortynine participants were randomized in isokinetic (IK), dynamic constant external resistance (DCER) unilateral eccentric training or control groups. Knee-extension 1RM and isometric, eccentric and concentric knee extensors' peak torques, as well as changes in vastus lateralis muscle thickness, fascicle length, pennation angle and quadriceps fat-free mass were measured. After training, both IK and DCER similarly increased over time 1RM (respectively, ?3.6 kg, CI 95 % 0.6-6.5 and ?4.3 kg, CI 95 % 1.6-6.9), concentric (respectively, ?8.4 N/m, CI 95 % 0.0 to ?16.4 and 9.8 CI 95 % 0.6-19.2), eccentric (respectively, ?28.5 N/m, CI 95 % 11.0 to ?46.0 and 21.1 CI 95 % 15.1-37.0), and isometric (respectively, ?15.4 N/m,, CI 95 % 0.3-27.5) peak torques. No increase was found for vastus lateralis muscle thickness, fascicle length, pennation angle and quadriceps fatfree mass. Eccentric training was effective for inducing strength, but not structural, adaptations in untrained limb. Both in rehabilitation and training practice, use of easily available gym devices can be a good substitute for expensive and often unavailable isokinetic devices.

Specific Adaptations in Performance and Muscle Architecture After Weighted Jump-Squat vs. Body Mass Squat Jump Training in Recreational Soccer Players

“…The strength measurements were preceded by a standardized warm-up, consisting of three sets x 10 repetitions of weight-free squats. Quadriceps peak-torque was measured in concentric (1.05 rad • s -1 ) and eccentric (-1.05 rad • s -1 ) modalities (12). Hamstrings peak-torque was measured in eccentric (-1.05 rad • s -1 ) modality.…”

“…Vastus lateralis muscle architecture was measured using an ultrasound device (Acuson P50, Siemens, Germany) at the 39% of the distal length of the thigh (12). The participants laid supine and the 4 cm ultrasound transducer was oriented perpendicularly to the skin surface of the vastus lateralis and longitudinally to the muscle's fascicles.…”

Effects of Combined Aerobic-Strength Training vs Fitness Education Program in COPD Patients

“…Whole-body composition (fat mass percentage [FM, %], lean mass percentage [LM, %], and bone mineral content [BMC, kg]) was evaluated by means of dual-energy X-ray absorptiometry (DXA) using a total body scanner (QDR Explorer W, Hologic, Marlborough, MA, USA; fan-beam technology, software for Windows XP version 12.6.1) according to the manufacturer's instructions. All scans were performed by a single operator [10].…”

The Activation of Gluteal, Thigh, and Lower Back Muscles in Different Squat Variations Performed by Competitive Bodybuilders: Implications for Resistance Training

“…Bodybuilders have a unique capacity to perform exercises with a profound consistency of their technique, and were recently used to investigate the differences in muscle activation when bench press [ 16 ] or shoulder raise variations [ 17 ] are performed. Additionally, examining the muscle activation during both the concentric and the descending phase may help practitioners to characterize the strength and the hypertrophic stimuli, given both the short-term [ 18 , 19 ] and long-term unique responses following traditional or eccentric-based exercise training [ 2 , 20 , 21 , 22 ]. Therefore, the present study investigated the differences in the gluteal, thigh, and lower back muscles’ activation in bodybuilders when varying the squatting technique.…”