Scientists at Pennsylvania State University began to fill this gap through a study. They studied 35 athletes in the US military. These subjects are soldiers who have undergone at least two years of standard military training, including three times a week. The training content includes high-intensity strength and endurance training. By studying the changes of skeletal muscle, their compatibility was compared.
In this study, subjects were randomly divided into four groups.
1. Just high-intensity endurance training (group E, 8 people)
2. Just high-intensity whole-body strength training (st group, 9 people)
3. Comprehensive high-intensity whole-body strength training and endurance training (Group C, 9 people)
4. Comprehensive high-intensity upper limb strength training and lower limb endurance training (UC group, 9 people)
High-intensity strength training includes flat bench press, flying birds, upright rowing, neck pull-down, sitting rowing, one-legged knee bending, heel lifting and so on. The training program aims to increase the size and strength of muscles. High-intensity endurance training includes 40-minute longest running and interval training from 200 meters to 800 meters. The training program aims to optimize oxygen uptake.
Test method:
Strength test: Using 1-RM method, the maximum dynamic strength of upper and lower body muscle tissue was obtained by three kinds of exercise modes: bench press, back push and leg flexion and extension. 1-RM is the maximum weight that can be lifted by a complete action. There was no injury in any strength test.
Living muscle sampling: used to test the changes of muscle fibers before and after training. Skin acupuncture was used to take live muscle samples 10 and 48 hours after the last training. The surface part of the lateral thigh muscle was sampled by skin needle biopsy technique.