Muscular strength and power development to high and low resistance loads in trained individuals. : 8-week intervention

Sammanfattning: Aim The purpose of this study was to examine high versus low resistance training loads performed to muscular failure and its effect on muscular strength, power and strength endurance. Method 11 men and 3 women (age 26,4 ±4,4 years, weight 79,9 ±10,7 kg, height 179,4 ±76 cm) were recruited to train for 2 days/week for 8-weeks in the leg press and leg extension. One leg was randomly allocated to a high load (HL) program performing 3-5 reps and the other leg was allocated to the low load (LL) program, performing 20-25 reps. All sets were executed to muscular fatigue. The participants were measured for 1RM strength, strength endurance and muscular power before and after the study. Results HL and LL leg significantly improved strength gains in the LP exercise by 20,3%, respectively 21%, P< 0,001, but no difference was noted between legs P= 0,876. HL displayed significant increases in the LE exercise by 10,3%, P< 0,05, while no significant improvement occurred for the LL leg, -2,7%, P> 0,05. Strength remained insignificantly similar between protocols P> 0,05. The mean power results indicated no significant improvements within protocols, HL P= 0,309, LL P= 0,112. There was also no significant difference between the two protocols after the intervention P= 0,646. As for muscular strength endurance, the LL performed more repetitions which was significantly greater than for the HL leg 26,5 reps, respectively 23,9 reps, P= 0,045. Conclusion This study concludes that similar strength gains can be accomplished when training with heavier or lighter loads as long as all resistance training is performed to muscular failure. It was also determined that performing lower loads to failure is superior for local strength endurance. Finally, traditional resistance training has no benefit for augmenting muscular power whether training with higher or lighter loads to exhaustion