Torque-velocity characteristics and contractile rate of force development in elite badminton players

Elite badminton requires muscular endurance combined with appropriate maximal and explosive muscle strength. The musculature of the lower extremities is especially important in this context since rapid and forceful movements with the weight of the body are performed repeatedly throughout a match. In the present study, we examined various leg-strength parameters of 35 male elite badminton players who had been performing resistance exercises as part of their physical training for several years. The badminton players were compared with an age-matched reference group, the members of whom were physically active on a recreational basis, and to the same reference group after they had performed resistance training for 14 weeks. Maximal muscle strength of the knee extensor (quadriceps) and flexor muscles (hamstrings) was determined using isokinetic dynamometry. To measure explosive muscle strength, the contractile rate of force development was determined during maximal isometric muscle contractions. In general, the badminton players showed greater maximal muscle strength and contractile rate of force development than the reference group: mean quadriceps peak torque during slow concentric contraction: 3.69 Nm center dot kg(-1), (s) =0.08 vs. 3.26 Nm center dot kg(-1), (s) =0.8 (P <0.001); mean hamstring peak torque during slow concentric contraction: 1.86 Nm center dot kg(-1), s=0.04 vs. 1.63 Nm center dot kg(-1), (s) = 0.04 (P <0.001); mean quadriceps rate of force development at 100 ms: 24.4 Nm center dot (-1)(s) center dot kg(-1), (s)=0.5 vs. 22.1 Nm center dot (-1)(s) center dot kg(-1), (s)=0.6 (P <0.05); mean hamstring rate of force development at 100 ms: 11.4 Nm center dot (-1)(s) center dot kg(-1), (s)= 0.3 vs. 8.9 Nm center dot (-1)(s) center dot kg(-1), (s) = 0.4 (P <0.05). However, after 14 weeks of resistance training the reference group achieved similar isometric and slow concentric muscle strength as the badminton players, although the badminton players still had a higher isometric rate of force development and muscle strength during fast (240 degrees center dot (-1)(s)) quadriceps contractions. Large volumes of concurrent endurance training could have attenuated the long-term development of maximal muscle strength in the badminton players. The badminton players had a higher contractile rate of force development than the reference group before and after resistance training. Greater explosive muscle strength in the badminton players might be a physiological adaptation to their badminton training.