Adaptation to long-term strenth training in rats and decaying characteristics after detraining

Introduction

Detraining is an unavoidable experience for many athletes participating in athletic training due to some unexpected incidences such as injuries, and it has very important effect on detrained athlete’s performance. This study tries to observe adaptation to long-term strength training and decaying characteristics of achieved training effect after detraining so as to provide coaches with some considerations to deal with athlete’s rehabilitation from injury.

Methods

44 SD rats were divided into two groups. Two group executed same strength training program in first 6 weeks: intermittent jumping training (30 cm for jumping height )with electric stimulus (50 Hz, 20 ~50v), 3times (70×3 per time) per week. After 6 weeks, Detrained Group no longer continued to training in following 6 successive weeks while another group continued same training program. Samplings, from Calf Intestines muscle of back lower limb, were made in week 0, week 6, week 8, week 10 and week 12, respectively. Measured parameters included ATPase, LDH, SDH, and O.D value of muscular glycogen (with Multi-function Real-color Pathological image Analyzer).

Results

1. After 6-week training: muscular glycogen concentration significantly increased by 9.37% (p<0.05), ATPase by 13.33% (p<0.01), LDH by 27.83% (p<0.01), SDH by 33.33% (p<0.01).
2. During 6-week detraining: Increased glycogen through training did not show significant decrease during first 4 weeks, however in week 6 after detraining, it significantly lowered to near pre-training level. ATPase and LDH level had significantly decreased to week 4 after detraining, while SDH level to week 2.

Discussion/Conclusion

1. Jumping training can increases concentration of muscular glycogen with favorite result. This reflects this strength training method can efficiently improve status of this energy substrate, and can indirectly improve anaerobic performance.
2. Jumping training can significantly increase concentration of ATPase, LDH and SDH. This indicates that both aerobic and anaerobic capacity can be improved through this training.
3. Every parameter showed a progressively decaying trend after detraining, however, their decay is not synchronous. SDH’s decaying rate is the fastest, and glycogen is the lowest. This indicates that increased glycogen level can maintain longer duration after detraining
Acknowledgement
This project was funded by the China National Sports General Bureau.

References

[1]. Petibois C, Deleris G (2003). Effects of short- and long-term detraining on the metabolic response to endurance exercise. Int J Sports Med. Jul;24(5):320-5.
[2]. Tokmakidis SP, Volaklis KA (2003). Training and detraining effects of a combined-strength and aerobic exercise program on blood lipids in patients with coronary artery disease. J Cardiopulm Rehabil. May-Jun;23(3):201-2.
[3]. McGowan CM, Golland LC, Evans DL, Hodgson DR, Rose RJ (2002). Effects of prolonged training, overtraining and detraining on skeletal muscle metabolites and enzymes. Equine Vet J Suppl. Sep;(34):257-63.
[4]. Mujika I, Padilla S (2001). Muscular characteristics of detraining in humans. Med Sci Sports Exerc. Aug;33(8):1297-303.