Different Patterns in Muscular Strength and Hypertrophy Adaptations in Untrained Individuals Undergoing Non-Periodized and Periodized Strength Regimens.

This study investigated the effects of non-periodized (NP), traditional periodization (TP) and daily undulating (UP) regimens on muscle strength and hypertrophy in untrained individuals. Thirty-three recreationally active males were randomly divided into four groups: NP: n = 8; TP: n = 9; UP: n = 8 and control group (C): n = 8. Experimental groups underwent a 12-week strength-training program consisting of two sessions per week. Muscle strength and quadriceps cross-sectional area (QCSA) were assessed at baseline, 6-wk (i.e. mid-point) and after 12-wk. All training groups increased squat 1RM from pre to 6-wk mid (NP: 17.02%, TP: 7.7% and UP: 12.9%, p≤0.002) and pre to post 12-wk (NP: 19.5%, TP: 17.9% and UP: 20.4%). TP was the only group that increased squat 1RM from 6-wk mid to 12-wk period (9.4%, p≤0.008). All training groups increased QCSA from pre to 6-wk mid (NP: 5.1%, TP: 4.6% and UP: 5.3%, p≤0.0006) and from pre to post 12-wk (NP: 8.1%, TP: 11.3% and UP: 8.7%). From 6-wk mid to 12-wk period, TP and UP were the only groups that increased QCSA (6.4% and 3.7%, p≤0.02). There were no significant changes for all dependent variables in C group across the time (p≥0.05). In conclusion, our results demonstrated similar training-induced adaptations after 12-wk of NP and periodized regimens. However, our findings suggest that in the latter half of the study (i.e. after the initial 6 weeks), the periodized regimens elicited greater rates of muscular adaptations compared to NP. Strength coaches and practitioners should be aware that periodized regimens might be advantageous at latter stages of training even for untrained individuals.