Ian Tricoli

We compared the effects of varied and constant resistance exercises on muscular adaptations in young women. Seventy young women (21.8 ± 3.4 yrs, 62.0 ± 12.3 kg, 162.3 ± 5.7 cm) were randomly divided into two groups: constant resistance exercises (CON-RE, n = 38) or varied resistance exercises (VAR-RE, n = 32). The resistance training (RT) was performed thrice a week over 10 weeks. CON-RE performed a 45º leg press and stiff-leg deadlift in every training session, while VAR-RE performed 45º leg press and stiff-leg deadlift in the first training session of the week, hack squat and prone leg curl in the second, and Smith machine squat and seated-leg curl in the third. Both groups performed two sets of 10-15 repetitions maximum per resistance exercise. We measured the muscle thickness of the thigh's anterior, lateral, and posterior aspects by ultrasonography at different muscle sites (proximo-distal). Muscular strength was analyzed from the one-repetition maximum (1RM) tests in the 45° leg press and leg extension (non-trained exercise). The muscle thickness increased similarly in both groups for all muscles and sites (CON-RE: +7.8-17.7% vs. VAR-RE: +7.5-19.3%, p > .05). The 1RM increased similarly in both groups (CON-RE: +24.4-32.1% vs. VAR-RE: +29.0-30.1%, p > .05). Both RT routines resulted in virtually similar muscular strength gains and hypertrophy. Therefore, both strategies should be considered for the improvement of strength and muscle growth.

We compared the effects of different weekly calf training sets on muscle size changes. Sixty-one untrained young women performed a calf training program for 6 weeks, 3 d·wk–1, with differences in resistance training volume. The participants were randomly assigned to one of the three groups: 6-SET, 9-SET, and 12-SET weekly calf training sets. The calf raise exercise was performed in sets of 15–20 repetitions maximum. The muscle thickness measurements of medial gastrocnemius (MG), lateral gastrocnemius (LG), and soleus (SOL) were taken via B-mode ultrasound. We used the sum of the three-muscle thickness as a proxy for the triceps surae (TSSUM). The 12-SET group elicited greater increases than the 6-SET in LG (6-SET=+ 8.1% vs. 12-SET=+ 14.3%; P=0.017), SOL (6-SET=+ 6.7% vs. 12-SET=+ 12.7%; P=0.024), and TSSUM (6-SET=+ 6.9% vs. 12-SET=+ 12.0%; P=0.005), but there was no significant difference in MG changes (6-SET=+ 6.6% vs. 12-SET=+ 9.9%; P=0.067). There were no significant differences when comparing 9-SET vs. 6-SET and 12-SET (P≥0.099). Although all groups experienced calf muscle hypertrophy, our results suggest that the higher dose range may optimize triceps surae muscle size gains.