The Effects Of Different Local Muscular Endurance Training Protocols In Muscle Activity And Fatigue

Abstract : The present study assessed fatigue and neuromuscular changes after fatiguing submaximal horizontal chest press exercise between different strength trainings of concentric contractions intensities. PURPOSE: The purpose of this study was to evaluate the effect of strength trainings with higher intensity contractions in EMG activity and fatigue. METHODS: Fifteentrained males (24.1±2.9 years old, 181.8±5.8cm, 83.6±9.6kg) performed four different strength trainings protocols in horizontal chest press (HCP) with different intensities of a load % one repetition maximum (RM) with a similar total impulse and similar rest. Strength trainings protocols consisted of: A) 3 blocks x (1 repetition (reps) of 95% RM - 1 rep of 90% RM - 3 reps of 80% RM - 5 reps of 70% RM - 8 reps of 60% RM - 8 reps of 50% RM - 12 reps of 45% RM - 15 reps of 30% RM - 12 reps of 20% RM) rest 5 sec between sets et 3 min between blocks; B) 2 blocks x (6 x 15 of 50% RM) rest 30 sec between sets et 3 min between blocks; C) 3 sets x (3 reps of 90% RM) rest 30 sec between sets and 1 min rest after block and 4 X (15 of 50% RM) rest 20 sec between sets and 1'40” rest after block and 3 X (15 of 50%) rest 20 sec between sets; D) 3 blocks x (6 x 10 reps of 50% RM) rest 10 sec between sets and 2'30” after bloc. The maximal voluntary isometric contraction torque (MVIC) was assessed in the HCP exercisebefore and after exercise. Electromyography (EMG) of the pectoralis major (P), anterior deltoid (AD), and the long head of the triceps brachii (TB) were assessed during the different exercises. RESULTS: Similar reductions of the MVIC (1227.5±184 vs 992±196 N; P<0.01) were observed after the four strength training protocols.EMG DA activity was greater in protocol C compared to the other protocols (0.956±0.336 vs 0.878±0.347 mV; P=0.01). EMG TB activity was greater in protocol C compared to the other protocols (0.534±0.194 vs 0.473±0.249 mV; P=0.01).EMG P activity was greater in protocol B and D compared to the A and C (0.343±0.115 vs 0.329±0.170 mV; P=0.01). CONCLUSIONS: The effect of strength endurance trainings with higher load % RM contractions compared to the others with a lower, affect similarly the loss of performance in the HCP exercise but with greater activity of DA and T muscles.