Further Potentiation of Dynamic Muscle Strength after Resistance Training

• Published in: Medicine and science in sports and exercise 2013-07, Vol.45 (7), p.1323-1330
• Main Authors: MIYAMOTO, NAOKAZU, WAKAHARA, TAKU, EMA, RYOICHI, KAWAKAMI, YASUO
• Format: Article
• Language: English
• Subjects: Adult; Analysis of Variance; Biological and medical sciences; Biomechanical Phenomena; Electromyography; Fundamental and applied biological sciences. Psychology; Healthy Volunteers; Human physiology applied to population studies and life conditions. Human ecophysiology; Humans; Knee Joint - physiology; Male; Medical sciences; Muscle Contraction - physiology; Muscle Fatigue - physiology; Muscle Strength - physiology; Muscle Strength Dynamometer; Quadriceps Muscle - physiology; Range of Motion, Articular; Resistance Training - methods; Space life sciences; Torque; Vertebrates: body movement. Posture. Locomotion. Flight. Swimming. Physical exercise. Rest. Sports
• ISSN: 0195-9131; 1530-0315
• DOI: 10.1249/MSS.0b013e3182874c0e

PURPOSEOne bout of 5–6 s of maximal voluntary isometric contraction (MVC) is known to enhance subsequent dynamic joint performance such as dynamic joint torque and power with maximal voluntary effort. On the other hand, such a muscle contraction can also induce muscle fatigue. It is then possible that individual differences in fatigue resistance is a factor that affects the balance between potentiation and fatigue. Here, we examined the effect of chronic heavy-resistance training on the extent and time course of the potentiation of maximal voluntary dynamic torque. METHODSBefore and after a 12-wk intervention, maximal voluntary concentric knee extension torque at 210°·s was measured in the following sequencebefore and immediately after a 5-s MVC of knee extension and 1, 3, and 5 min thereafter. The training group performed heavy-resistance training exercise of knee extension consisting of five sets of eight repetitions with 80% of one-repetition maximum, three sessions a week during the intervention period. RESULTSBefore the resistance training intervention, maximal voluntary concentric torque was significantly enhanced only at 1 and 3 min post-MVC. After the 12-wk resistance training, the maximal voluntary concentric torque was potentiated also immediately after the conditioning MVC and was further increased at 1-min point. CONCLUSIONThese findings indicate that the contraction-induced potentiation of maximal voluntary dynamic torque is pronounced in strength-trained individuals.