AIM: The aim of this study was to investigate the relationship between the activation level of certain protagonist muscles of the upper and lower body during the shot-put with the shot-put performance in skilled athletes. METHODS: Eight experienced right-handed shot-putters, performed the shot-put with the linear technique. They also performed a maximum (1RM) squat and a 1RM incline bench-press strength test. Electromyographic (EMG) signals were recorded from the m. quadriceps vastus lateralis (VL), m. gastrocnemius internus, m. pectoralis major (PEC) and the m. triceps brachii (TRI) of the right side during all efforts. The level of EMG during the shot-put was normalized relatively to that measured during the respective maximum strength test. RESULTS: Shot-put performance was significantly correlated with 1RM squat (r=0.76, P<0.05) and 1RM bench-press (r=0.75, P<0.05) as well as with the average EMG from VL and PEC after taking the power position (r=0.91, P<0.01 and r=0.75, P<0.05, respectively). A close negative relationship was also found between shot-put performance and the time to reach peak activation of right TRI during the explosive strike of the throwing arm (r=-0.70, P<0.05). CONCLUSION: These results suggest that, besides the importance of absolute muscle strength, an important parameter for shot-put performance is the level of activation of the VL and the PEC during the delivery phase. Furthermore, these data suggest that the TRI should be activated fast in order to be an effective contributor to the shot-put performance.

BACKGROUND: Skeletal muscle wasting commonly occurs in patients with chronic obstructive pulmonary disease (COPD) and has been associated with the presence of systemic inflammation. This study investigated whether rehabilitative exercise training decreases the levels of systemic or local muscle inflammation or reverses the abnormalities associated with muscle deconditioning. METHODS: Fifteen patients with COPD (mean (SE) forced expiratory volume in 1 s 36 (4)% predicted) undertook high-intensity exercise training 3 days/week for 10 weeks. Before and after the training programme the concentration of tumour necrosis factor alpha (TNFalpha), interleukin-6 (IL-6) and C-reactive protein (CRP) in plasma was determined by ELISA, and vastus lateralis mRNA expression of TNFalpha, IL-6, total insulin-like growth factor-I (IGF-I) and its isoform mechanogrowth factor (MGF) and myogenic differentiation factor D (MyoD) were assessed by real-time PCR. Protein levels of TNFalpha, IGF-I and MyoD were measured by Western blotting. RESULTS: Rehabilitation improved peak exercise work rate by 10 (2%) (p = 0.004) and mean fibre cross-sectional area from 4061 (254) microm(2) to 4581 (241) microm(2) (p = 0.001). Plasma inflammatory mediators and vastus lateralis expression of TNFalpha and IL-6 were not significantly modified by training. In contrast, there was a significant increase in mRNA expression of IGF-I (by 67 (22)%; p = 0.044), MGF (by 67 (15)%; p = 0.002) and MyoD (by 116 (30)%; p = 0.001). The increase observed at the mRNA level was also seen at the protein level for IGF-I (by 72 (36)%; p = 0.046) and MyoD (by 67 (21)%; p = 0.012). CONCLUSIONS: Pulmonary rehabilitation can induce peripheral muscle adaptations and modifications in factors regulating skeletal muscle hypertrophy and regeneration without decreasing the levels of systemic or local muscle inflammation.