Search

Davies, TB, Li, J, and Hackett, DA. Effect of high-volume cluster sets vs. lower-volume traditional sets on accuracy of estimated repetitions to failure. J Strength Cond Res37(6): 1191–1198, 2023—This study investigated the effects of resistance training using cluster (CLUS) vs. traditional (TRAD) set structures on the accuracy of estimated repetitions to failure (ERF). Nineteen healthy male resistance trainers (age 21.0 ± 4.4 years) were randomized into 1 of the 2 bench press training routines performed for 6 weeks. Cluster (n= 10) performed 6 sets of 5 repetitions at 85% of 1 repetition maximum (1RM) with 30-second interrepetition rest and 3 minutes of interset rest. Traditional (n= 9) performed 3 sets of 5 repetitions at 85% 1RM with 5 minutes of interset rest. Maximum repetitions at 85% 1RM was performed before and after intervention to assess error in ERF and mean concentric velocity (MCV). The ERF, rating of perceived exertion, and maintenance of MCV were assessed throughout the intervention. Rating of perceived exertion was lower for sets 1–3 in CLUS compared with TRAD from weeks 1 to 4 (effect size [ES] = 0.8–2.4, p≤ 0.04). The ERF was greater for sets 1–3 in CLUS than in TRAD during all intervention weeks (ES = 1.0–5.1, p≤ 0.04). Maintenance of MCV was greater in CLUS compared with TRAD for all sets at week 1 (ES = 0.76, p= 0.002) and sets 4–6 at week 6 (ES = 0.77, p= 0.006). After the intervention, error in ERF did not change, and no differences were found between the groups. Findings indicate that accuracy of ERF does not improve after resistance training using set structures that induce different transient fatigue-related effects when using high loads in experienced resistance trainers.

Li, J, Davies, TB, and Hackett, DA. Self-reported training and supplementation practices between performance-enhancing drug-user bodybuilders compared with natural bodybuilders. J Strength Cond Res37(5): 1079–1088, 2023—This study aimed to examine whether the training and supplementation practices differ between performance-enhancing drug (PED)-using bodybuilders (BB) and natural BB. One hundred eighty-seven competitive male bodybuilders with a median age of 27.0 years completed an online survey. Of this sample, 40 respondents reported using PED (PED-user) and 147 respondents reported to be natural. Compared with natural BB, PED-user BB reported greater off-season body weight (p< 0.001) and weight loss before a competition (p< 0.001). In the off-season, PED-user BB performed a greater number of exercises per muscle group (p< 0.001), number of repetition maximum (RM) per set (p< 0.01), and less recovery between the sets (p< 0.01). During the precompetition phase, the natural BB increased their number of RM; however, the PED-user BB still reported using a greater number of RM per set (p= 0.02), exercises per muscle group (p< 0.001), and less recovery time between the sets (p< 0.01). Both the PED-user BB and natural BB reported greater aerobic exercise frequency (p< 0.001) and session duration (p< 0.001), although PED-user BB performed a greater number of aerobic exercise sessions (p= 0.04) and at a higher intensity (p< 0.01). Advanced training techniques, including negatives, partial repetitions, preexhaustion sets, and timed repetitions, were more popular among PED-user BB (p< 0.05). Creatine monohydrate usage was more popular among natural BB (p< 0.001), whereas branched-chain and essential amino acids were more popular among PED-user BB (p≤ 0.001). Findings suggest that PED-user BB perform more metabolically demanding resistance training sessions, more strenuous aerobic training during the precompetition phase, and may have different supplementation preferences compared with natural BB.

Hackett, DA, He, W, Fleeton, JRM, Orr, R, and Sanders, RH. Effects of age and sex on aerobic fitness, sprint performance, and change of direction speed in high school athletes. J Strength Cond Res37(5): 325–331, 2023—The purpose of this study was to examine the effects of sex and age on aerobic fitness, sprinting performance, and change of direction speed (CODS) in high school athletes, with consideration for maturity. This cross-sectional study involved 2,132 adolescents (1,415 male and 717 female athletes) aged 12.0–15.9 years. Assessment of aerobic fitness using the 20-m multistage fitness test (20MSFT) and 20-m sprint and CODS using the 505 test was performed. For the analysis of data, subjects were separated into 4 age groups: U/13 years, U/14 years, U/15 years, and U/16 years. Estimated age at peak height velocity was a covariate in the data analysis to control for maturity status. Compared with female athletes, male athletes had superior performances at all age groups in 10-m sprint (p< 0.001, effect size [ES] = >−0.44), 20-m sprint (p< 0.001, ES = >−0.55), and 505 test (p< 0.001, ES = >−0.41). Female athletes performed better than male athletes in 20MSFT at U/13 (p< 0.01, ES = −0.22); however, male athletes had better performances at U/15 (p< 0.01, ES = 0.27) and U/16 (p< 0.001, ES = 0.67). At each consecutive age group, male athletes improve their performances in 20MSFT and sprints and at U/14 and U/16 in the 505 test (p< 0.001, ES > −0.37). Female athletes showed no improvement in the 20MSFT and 505 test between U/13-U/16 but showed improved sprint performance at U/15 compared with U/13 and at U/16 compared with U/14 (p< 0.05). This study shows that adolescent male athletes perform consistently better than female athletes in running-related field-based tests and display continuous improvements across age groups.

Hackett, DA. Influence of movement velocity on accuracy of estimated repetitions to failure in resistance-trained men. J Strength Cond Res36(10): 2701–2708, 2022—This study explored the accuracy in estimated repetitions to failure (ERF) and changes in mean concentric velocity (MCV) during resistance exercise. Twenty male resistance trainers (age, 26.3 ± 6.9 years; body mass, 82.0 ± 6.0 kg; stature, 178.0 ± 5.5 cm) completed 5 sets of 10 repetitions for the bench press and squat at 70% one-repetition maximum. Subjects' reported their rating of perceived exertion (RPE) and ERF after the 10th repetition of each set and then continued repetitions to momentary muscle failure (5-minute recovery between sets). Barbell velocity was assessed using a linear position transducer. For the bench press, MCV at repetitions 9–10 decreased as sets progressed (p≤ 0.005) with a greater loss of MCV for sets 3–5 vs. set 1 (p≤ 0.005). No significant changes in MCV variables were found across sets for the squat. Error in ERF was greater in set 1 for the bench press (p≤ 0.005) with no differences for the remaining sets. There were no differences between sets for error in ERF for the squat. Moderate to strong relationships were found between most MCV variables and RPE and ERF, for the bench press (rs= −049 to 0.73; p≤ 0.005). For the squat only, MCV at repetitions 9–10 was moderately related with RPE (rs= −0.33; p≤ 0.003) and actual repetitions to failure (rs= 0.31; p≤ 0.003). No significant relationships were found for error in ERF for either the bench press or squat. Changes in MCV across sets may influence perception of effort and performance for the bench press; however, it does not influence the accuracy in ERF for either exercise.

Davies, TB, Halaki, M, Orr, R, Mitchell, L, Helms, ER, Clarke, J, and Hackett, DA. Effect of set structure on upper-body muscular hypertrophy and performance in recreationally trained men and women. J Strength Cond Res36(8): 2176–2185, 2022—This study explored the effect of volume-equated traditional-set and cluster-set structures on muscular hypertrophy and performance after high-load resistance training manipulating the bench press exercise. Twenty-one recreationally trained subjects (12 men and 9 women) performed a 3-week familiarization phase and were then randomized into one of two 8-week upper-body and lower-body split programs occurring over 3 and then progressing to 4 sessions per week. Subjects performed 4 sets of 5 repetitions at 85% one repetition maximum (1RM) using a traditional-set structure (TRAD, n= 10), which involved 5 minutes of interset rest only, or a cluster-set structure, which included 30-second inter-repetition rest and 3 minutes of interset rest (CLUS, n= 11). A 1RM bench press, repetitions to failure at 70% 1RM, regional muscle thickness, and dual-energy x-ray absorptiometry were used to estimate changes in muscular strength, local muscular endurance, regional muscular hypertrophy, and body composition, respectively. Velocity loss was assessed using a linear position transducer at the intervention midpoint. TRAD demonstrated a significantly greater velocity loss magnitude (g= 1.50) and muscle thickness of the proximal pectoralis major (g= −0.34) compared with CLUS. There were no significant differences between groups for the remaining outcomes, although a small effect size favoring TRAD was observed for the middle region of the pectoralis major (g= −0.25). It seems that the greater velocity losses during sets observed in traditional-set compared with cluster-set structures may promote superior muscular hypertrophy within specific regions of the pectoralis major in recreationally trained subjects.

Hackett, DA. Training, supplementation, and pharmacological practices of competitive male bodybuilders across training phases. J Strength Cond Res36(4): 963–970, 2022—Bodybuilding involves the pursuit of muscularity and leanness primarily through the use of progressive resistance training in combination with other practices such as manipulation of diet and use of ergogenic aids. This study aimed to compare the training practices and ergogenic aids used by competitive male bodybuilders across training phases. An online survey was completed by 235 competitive male bodybuilders with a median age of 26.0 (interquartile range 23.0–31.3) years. Results showed that most respondents performed split-routines (85.5%), 4–7 sessions per week (95.7%), trained major muscle groups twice a week (>50%), and session duration being 60–90 minutes (55.7%). Off-season resistance training sessions mostly comprised of targeting 2–3 muscle groups (56%), 2–3 exercises per muscle group (60.4%), 3–4 sets per exercise (73.2%), 7–12 repetition maximum (RM) per set (71.6%), and 61–180 seconds recovery between sets and exercises (80.5%). At the precompetition phase (6 weeks before competition), there was a decrease in the number of muscle groups trained per session (p= 0.027) and a greater number of repetitions performed per set (p< 0.001). A significant increase in the reported aerobic exercise volume was found during precompetition (<0.001). Performance enhancing drugs were used by 53.6% of respondents who did not compete in natural bodybuilding competitions. Dietary supplements were used by 95.7% of respondents with the most common being creatine monohydrate (80.4%) and whey protein (65.8%). Findings suggest that competitive bodybuilders follow resistance training practices consistent with the broad muscular hypertrophy recommendations but a notable shift in practices occur in the weeks before competition.