The late Carmelo Bosco did quite a bit of research in this area. Following are a couple of studies.
Adaptive response of human skeletal muscle to simulated hypergravity condition.
The mechanical behaviour of leg extensor muscles of five international-level athletes was evaluated during 13 months training period. Drop jumps, average mechanical power during 15 S continuous jump, and vertical jumps performed with and without extra weights were used to measure explosive power characteristics. The data recorded in vertical jumps was utilized for construction of force-velocity relationship (F-V curve). The athletes did not show improvement in any of the variables studied after 12 months of intensive systematic training programme. It was assumed that the subjects already had reached their upper limit of performance. However, after that the athletes underwent a simulated 3 weeks high-gravity period. The hypergravitational condition was created by wearing a special vest filled with extra loads (11% of BW). The vest was used from morning to evening. No changes in the ordinary training programme were allowed. After the simulated high-gravity conditioning period significant improvement in almost all the variables studied was observed (P less than 0.05-0.001). Vertical jump performance was enhanced from 44.3 to 54.9 cm. The F-V curve remained stable all year but after hypergravity period shifted markedly to the right. The drastic improvement was attributed to be caused by a fast adaptation to the new functional requirements (I.I g). Therefore, once the biological adaptation occurred the mechanical behaviour of the athlete’s leg extensor muscle was similar to that which could be experienced in a field at low gravity condition (0.9 g). Adaptive response to the hypergravity conditioning was speculated to occur mainly at neurogenic level and less in myogenic component.
The influence of extra load on the mechanical behavior of skeletal muscle.
Bosco C, Zanon S, Rusko H, Dal Monte A, Bellotti P, Latteri F, Candeloro N, Locatelli E, Azzaro E, Pozzo R, et al.
Eleven international jumpers and throwers engaged in year round training were divided into experimental (n = 6) and control (n = 5) groups. The experimental group was tested before and after a 3 weeks simulated hypergravity period, and again 4 weeks after the hypergravity period. The high gravity condition was created by wearing a vest weighing about 13% of the subjects body weight. The vest was worn from morning to evening including the training sessions, and only removed during sleep. The daily training of all subjects consisted of classical weight training and jumping drills. No changes in the ordinary training program were allowed in the experimental group, except for the use of the vest. Vertical jumps, drop jumps and a 15 s continuous jumping test were used to measure the explosive power characteristics of the subjects. After the hypergravity period the experimental subjects demonstrated significant (5-10%, P less than 0.05-0.01) improvements in most of the variables studied: however, 4 weeks after cessation of the high gravity period they tended to return towards the starting values. No changes were observed in the results of the control group. The improvement observed in the experimental subjects was explained as fast adaptation to the simulated high gravity field. It is suggested that adaptation had occurred both in neuromuscular functions and in metabolic processes