Acute Effects of Resistance Exercise on Intraocular Pressure in Healthy Adults: A Systematic Review.

ABSTRACT: Hackett, DA, Li, J, Wang, B, Way, KL, Cross, T, and Tran, DL. Acute effects of resistance exercise on intraocular pressure in healthy adults: A systematic review. J Strength Cond Res 38(2): 394-404, 2024-Intraocular pressure (IOP) tends to fluctuate during a resistance exercise (RE). This systematic review examines the acute effects of RE on IOP in healthy adults and factors that influence changes in IOP. Five electronic databases were searched using terms related to RE and IOP. A strict inclusion criterion was applied, which included being 55 years or younger with no medical conditions and RE intensity needing to be quantifiable (e.g., based on a maximal effort). Thirty-four studies met the inclusion criteria for this review. Isometric and isotonic contractions produced similar changes in IOP during RE up to 28.7 mm Hg. Exercises that involved larger muscle mass, such as squats and leg press, were found to produce changes in IOP during exercise ranging from 3.1 to 28.7 mm Hg. Smaller changes in IOP during RE were found for exercises engaging less muscle mass (e.g., handgrip and bicep curls). Intraocular pressure was found to increase during RE when lifting heavier loads and with longer exercise durations (e.g., greater repetitions). The Valsalva maneuver (VM) and breath-hold during RE accentuated the change in IOP, with more extreme changes observed with the VM. However, most studies showed that postexercise IOP returned to baseline after approximately 1 minute of recovery. An acute increase in IOP is observed during RE in healthy adults with fluctuations of varying magnitude. Factors that independently increase IOP during RE include exercises involving larger muscle mass, heavy loads, greater set duration, and when the VM or breath-hold is performed.

Effect of High-Volume Cluster Sets vs. Lower-Volume Traditional Sets on Accuracy of Estimated Repetitions to Failure.

ABSTRACT: 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 Res 37(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.

Self-Reported Training and Supplementation Practices Between Performance-Enhancing Drug-User Bodybuilders Compared with Natural Bodybuilders.

ABSTRACT: 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 Res 37(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.