Progressive resistance training volume: effects on muscle thickness, mass, and strength adaptations in resistance-trained individuals. J Strength Cond Res 36(3): 600-607, 2022-This study investigated the effects of 12-SET, 18-SET, and 24-SET lowerbody weekly sets on muscle strength and mass accretion. Thirty-five resistance-trained individuals (one repetition maximum [1RM] squat: body mass ratio [1RM: BM] 5 2.09) were randomly divided into 12-SET: n 5 13, 18-SET: n 5 12, and 24-SET: n 5 10. Subjects underwent an 8-week resistance-training (RT) program consisting of 2 weekly sessions. Muscle strength (1RM), repetitions to failure (RTF) at 70% of 1RM, anterior thigh muscle thickness (MT), at the medial MT (MMT) and distal MT (DMT) points, as well as the sum of both sites (SMT), along with region of interest for fat-free mass (ROI-FFM) were measured at baseline and posttesting. For the 1RM, there was a main time effect (p # 0.0001). However, there was a strong trend toward significance (p 5 0.052) for group-by-time interaction, suggesting that 18-SET increased 1RM back squat to a greater extent compared with 24-SET (24-SET: 9.

The purpose of this investigation was to compare the effects of auto-regulatory exercise selection (AES) vs. fixed exercise selection (FES) on muscular adaptations in strength-trained individuals. Seventeen males (Mean ± SD; age = 24 ± 5.45 years; height = 180.3 ± 7.54cm, lean body mass [LBM] 66.44 ± 6.59kg; squat and bench press 1RM: body mass ratio 1.87, 1.38 respectively) were randomly assigned into either AES or FES. Both groups trained three times a week for 9 weeks. AES self-selected the exercises for each session, whereas FES was required to perform exercises in a fixed order. LBM was assessed via DEXA and maximum strength via 1RM testing, pre and post training intervention. Total volume load was significantly higher for AES than for FES (AES: 573,288kg ± 67,505, FES: 464,600 ± 95,595, p=0.0240). For LBM, there was a significant main time effect (p=0.009). However, confidence interval analysis (95%CIdiff) suggested that only AES significantly increased LBM (AES: 2.47%, ES: 0.35, 95% CIdiff [0.030kg: 3.197kg], FES: 1.37 %, ES: 0.21, 95% CIdiff [-0.500kg: 2.475kg]). There was a significant main time effect for maximum strength (p≤0.0001). However, 95% CIdiff suggested that only AES significantly improved Bench-press 1RM (AES: 6.48%, ES: 0.50, 95% CIdiff [0.312kg: 11.42kg; FES: 5.14%, ES: 0.43 95%CIdiff [-0.311kg: 11.42kg]. On the other hand for back squat 1RM similar responses were observed between groups, (AES: 9.55%, ES: 0.76 95% CIdiff [0.04kg: 28.37kg], FES: 11.54%, ES: 0.80, 95%CIdiff [1.8kg: 28.5kg]. Our findings, suggest AES may provide a small advantage in LBM and upper body maximal strength in strength-trained individuals.

Evangelista, AL, De Souza, EO, Moreira, DCB, Alonso, AC, Teixeira, CVLS, Wadhi, T, Rauch, J, Bocalini, DS, Pereira, PEDA, and Greve, JMDA. Interset stretching vs. traditional strength training: effects on muscle strength and size in untrained individuals. J Strength Cond Res 33(7S): S159–S166, 2019—This study compared the effects of 8 weeks of traditional strength training (TST) and interset stretching (ISS) combined with TST on muscular adaptations. Twenty-nine sedentary, healthy adults were randomly assigned to either the TST (n = 17; 28.0 ± 6.4 years) or ISS (n = 12; 26.8 ± 6.1 years) group. Both groups performed 6 strength exercises encompassing the whole body (bench press, elbow extension, seated rows, biceps curl, knee extension, and knee flexion) performing 4 sets of 8–12 repetition maximum (RM) with a 90-second rest between sets. However, the ISS group performed static passive stretching, at maximum amplitude, for 30 seconds between sets. Both groups performed training sessions twice a week on nonconsecutive days. Muscle strength (i.e., 1RM) and hypertrophy (i.e., muscle thickness [MT] by ultrasonography) were measured at pre-test and after 8 weeks of training. Both groups increased 1RM bench press (p ≤ 0.0001): ISS (23.4%, CIdiff: 4.3 kg–11.1 kg) and TST (22.2%, CIdiff: 5.2 kg–10.9 kg) and 1RM knee extension (p ≤ 0.0001): ISS (25.5%, CIdiff: 5.6 kg–15.0 kg) and TST (20.6%, CIdiff: 4.4 kg–12.3 kg). Both groups increased MT of biceps brachii (BIMT), triceps brachii (TRMT), and rectus femoris (RFMT) (p ≤ 0.0001). BIMT: ISS (7.2%, CIdiff: 1.14–3.5 mm) and TST (4.7%, CIdiff: 0.5–2.5 mm), TRMT: ISS (12.3%, CIdiff: 1.1–4.4 mm) and TST (7.1%, CIdiff: 0.3–3.1 mm), and RFMT: ISS (12.4%, CIdiff: 1.1–2.9 mm) and TST (9.1%, CIdiff: 0.7–2.2 mm). For vastus lateralis muscle thickness (VLMT) and sum of the 4 muscle thickness sites (ΣMT), there was a significant group by time interaction (p ≤ 0.02) in which ISS increased VLMT and ΣMT to a greater extent than TST. Vastus lateralis muscle thickness: ISS (17.0%, CIdiff: 1.5–3.1 mm) and TST (7.3%, CIdiff: 0.7–2.1 mm), and ΣMT: ISS (10.5%, CIdiff: 6.5–9.0 mm) and TST (6.7%, CIdiff: 3.9–8.3 mm). Although our findings might suggest a benefit of adding ISS into TST for optimizing muscle hypertrophy, our data are not sufficient enough to conclude that ISS is superior to TST for inducing muscle hypertrophic adaptations. More studies are warranted to elucidate the effects of ISS compared with TST protocols on skeletal muscle. However, our findings support that adding ISS to regular TST regimens does not compromise muscular adaptations during the early phase of training (<8 weeks) in untrained individuals.

This study investigated the effects of two different velocity-based training (VBT) regimens on muscular adaptations. Fifteen female college volleyball players were randomly assigned into either progressive velocity-based training (PVBT) or optimum training load (OTL). Both groups trained three times a week for seven weeks. PVBT performed a 4-week strength block (e.g., 0.55–0.70 m·s−1) followed by a 3-week power block (e.g., 0.85–1.0 m·s−1), whereas OTL performed training at ~0.85–0.9 m·s−1. 1RM and peak power output (PP) assessments on the back squat (BS), bench press (BP) and deadlift (DL) exercises were assessed pre and post training. There was a main time effect (p ≤ 0.05) for BS and BP 1RM, (PVBT: 19.6%, ES: 1.72; OTL: 18.3%, ES: 1.57) and (PVBT: 8.5%, ES: 0.58; OTL: 10.2%, ES: 0.72), respectively. OTL increased DL 1RM to a greater extent than PVBT (p ≤ 0.05), (OTL: 22.9%, ES: 1.49; PVBT: 10.9%, ES: 0.88). Lastly, there was a main time effect (p ≤ 0.05) for BS, BP and DL PP, (PVBT: 18.3%, ES: 0.86; OTL: 19.8%, ES: 0.79); (PVBT: 14.5%, ES: 0.81; OTL: 27.9%, ES: 1.68); (PVBT: 15.7%, ES: 1.32; OTL: 20.1%, ES: 1.77) respectively. Our data suggest that both VBT regimens are effective for improving muscular performance in college volleyball players during the offseason period.

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.