Order of Resistance Training Cycles to Develop Strength and Muscle Thickness in Resistance-Trained Men: A Pilot Study

The aim of the present study was to assess the chronic effects of different order of resistance training cycles on strength and muscle thickness of recreationally resistance-trained men. The study sample was composed of 16 healthy men (age: 25.0 ± 3.8 years, height: 1.77 ± 7.6 cm, total body mass: 81.7 ± 10.4 kg, RT experience: 4.6 ± 0.7 years, relative bench press one repetition maximum: 1.2 ± 0.1, relative squat one-repetition maximum: 1.5 ± 0.2). According to baseline maximal strength, participants were allocated in one of the following groups: Maximal Strength-Strength Endurance (MS-SE) (six weeks of a maximal strength cycle followed by six weeks of a strength endurance cycle); Strength Endurance -Maximal Strength (MS-SE) (six weeks of a strength endurance cycle followed by six weeks of a maximal strength cycle). The following measurements were performed in the pre and post intervention periods: one-repetition maximum (1RM) on parallel back squat and bench press exercises, muscle thickness evaluation of biceps brachialis (MT_BB), triceps brachialis (MT_TB), and vastus lateralis (MT_VL) by ultrasonography. Total load lifted (TLL) and Internal training load (ITL) were also assessed. Both groups presented significant increases in bench press (MS-SE p = 0.001, SE-MS p = 0.003) and half squat (MS-SE p = 0.004, SE-MS p = 0.001) 1RM, MT_BB (MS-SE p = 0.020, SE-MS p = 0.005) and MT_TB (MS-SE p = 0.001, SE-MS p = 0.001). For MT_VL, a significant increase was observed only for MS-SE group (MS-SE p = 0.032, SE-MS p = 0.143). No significant difference between groups was observed for any strength or morphological outcomes. In conclusion, both MS-SE and SE-MS training cycles are effective strategies to enhance resistance training adaptations in trained men.