Hipertrofični odgovor mišic spodnjih okončin na različne intenzitete treninga za moč

This study evaluates the effectiveness of different resistance training intensities (high, moderate, and low) on quadriceps femoris muscle hypertrophy in healthy adults. A literature search was conducted in January 2023 using multiple databases, including Web of Science, SPORTDiscus, Embase, and PubMed. The methodological quality of the studies was assessed using the TESTEX scale. A total of 22 studies with 519 participants were included in this meta-analysis. Statistical analysis, performed using ReviewManager 5.2, showed that all resistance training intensities led to hypertrophy in the quadriceps femoris muscle compared to control or pre-test values. High-intensity training resulted in a muscle thickness increase of 2.3 mm (95% CI: 2.21-2.38), moderate-intensity training led to an increase of 1.88 mm (95% CI: 1.74-2.02), and low-intensity training showed an increase of 10.92 mm (95% CI: 10.77-11.08), all with p<.001. Meta-regression analysis revealed a significant relationship between training intensity and hypertrophy in the vastus intermedius (β=0.01, p=0.05, R$^²$=0.56) and vastus lateralis (β=0.01, p=0.007, R$^²$=0.34). However, no significant effect was found for the rectus femoris (β=0.03, p=0.417, R$^²$=0.04) or vastus medialis (β=0.003, p=0.895, R$^²$=0.002). In conclusion, resistance training at different intensities promotes hypertrophy across all quadriceps muscles, with variations depending on the specific muscle group. Meta-regression suggests that every 10% increase in training intensity corresponds to a 0.1 mm increase in vastus intermedius hypertrophy. No significant effect of training intensity was observed for the vastus lateralis, vastus medialis, or rectus femoris muscles.