Skeletal muscle mass and function tend to decline with increasing age. Insulin-like growth factor 1 (IGF-1) plays a key role in promoting skeletal muscle growth. Exercise improves skeletal muscle mass and function via activating the IGF-1 signaling. The aim of this study was to investigate whether different types of exercise could promote muscle hypertrophy, exercise and metabolic capacities, and activate IGF-1 signaling in early aging mice. 12-month-old male C57/BL6 mice were randomly divided into five groups: control group (CON), aerobic exercise group (AE), resistance exercise group (RE), whole-body vibration group (WBV) and electrical stimulation group (ES). Muscle weight, myofiber size, levels of IGF-1 signaling, oxidative stress, protein synthesis and degradation, and apoptosis in gastrocnemius muscle were detected. C2C12 cells were used to explore the mechanism. In this study, we confirmed that four modes of exercise increased skeletal muscle mass, exercise capacity, indicators of metabolism and protein synthesis, and inhibited oxidative stress and apoptosis via activating the IGF-1 pathway. The most effective intervention was RE. We found that WBV promoted muscle hypertrophy better than AE. Furthermore, in vitro experiment, the importance of IGF-1 / IGF-1R-PI3K / Akt signaling for maintaining skeletal muscle mass was further confirmed. AE, RE, WBV and ES increase skeletal muscle mass, exercise capacities, protein synthesis and metabolic enzyme activities, inhibit protein degradation and apoptosis in mice undergoing early aging via activating IGF-1 signaling. Among them, WBV has been shown to be significantly effective and has a similar effect of conventional exercise in promoting muscle hypertrophy.

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Objective: The purpose of the study is to explore the sEMG characteristics of associated major muscle groups (agonist muscles) in curving-round-bridge-posts event of 400m obstacle and its relationship with muscle performance. Methods: This study tested seven male military cadets who did quite well in 400m obstacle, and analyzed the original electromyography, iEMG and iEMG% data by using the surface electromyography telemetry and anatomical analysis of the action, combined with sEMG synchronal video data analysis. Results: The power order of the muscle strength in left upper limb and trunk muscle groups is: all test muscle groups are almost synchronized muscle power; the power order of the left lower limb muscle group and rectus abdoninis in sequence is: rectus abdoninis and tibialis anterior first generate power, followed by quadriceps, hamstrings, gastrocnemius, and gluteus maximus in sequence. The order of iEMG and iEMG% from large to small is: the left upper limbs and trunk muscle groups (biceps brachii muscle, latissimus dorsi muscle, triceps muscle of arm, trapezius muscle, wrist flexors, deltoid muscle, pectoralis major muscle, and wrist extensors); the left lower limb muscle and rectus abdoninis (rectus abdoninis, hamstrings, gluteus maximus, quadriceps, gastrocnemius, and tibialis anterior). Conclusion: In the process of curving round the bridge posts, the key action is to rely on upper limb and shoulder-back power to get the body close to the bridge post to control inertial deviation. The left arm should be pull out as soon as possible to avoid motion delay, and to make sure the body may approach the bridge post as close as possible and move rapidly along the shortest route. In teaching and training of the curving-round-bridge-posts activity, great efforts should be made to develop the muscle strength of the upper limb biceps, brachialis, triceps muscle of arm, wrist flexors, latissimus dorsi muscle and trapezius muscle; focus should also be put on improving the muscle strength of the lower limbs hamstrings, gluteus maximus, quadriceps, triceps surae, and rectus abdoninis.

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The study aims to predict the possible risks of sports injuries and provide theoretical basis for conducting targeted combat fitness training and strengthening capacity of combat readiness on a continuous basis through analysis and study of fundamental athletic ability of young male cadets in a military academy and their capability to perform basic movement patterns. The result of research shows that the overall performance of basic athletic ability of young male cadets in a military academy is good. However, there is still a significant gap in the ability to complete basic movement patterns. The major deficiencies are manifested in limited mobility of thoracic spine, shoulder, hip and ankle joints, as well as unbalanced development of bilateral muscle groups and limb functions in the lower limbs. In addition, the deficiencies also include the poor level of core muscle groups anti-rotation and reflex stability functions and insufficient extensibility of posterior chain muscle groups. In later combat physical teaching and training, the strategy of functional training should be introduced. In accordance with the final list of problems found in FMS tests, targeted sports training plans should be formulated to improve training efficiency on a scientific and dramatically reduce incidence of sports injuries.