Effects of Single Vs. Multiple Sets during 10 Weeks of Water-based Resistance Training on Neuromuscular Adaptations in Young Women

Maximal Number of Repetitions at Percentages of the One Repetition Maximum: A Meta-Regression and Moderator Analysis of Sex, Age, Training Status, and Exercise

The maximal number of repetitions that can be completed at various percentages of the one repetition maximum (1RM) [REPS ~ %1RM relationship] is foundational knowledge in resistance exercise programming. The current REPS ~ %1RM relationship is based on few studies and has not incorporated uncertainty into estimations or accounted for between-individuals variation. Therefore, we conducted a meta-regression to estimate the mean and between-individuals standard deviation of the number of repetitions that can be completed at various percentages of 1RM. We also explored if the REPS ~ %1RM relationship is moderated by sex, age, training status, and/or exercise. A total of 952 repetitions-to-failure tests, completed by 7289 individuals in 452 groups from 269 studies, were identified. Study groups were predominantly male (66%), healthy (97%), < 59 years of age (92%), and resistance trained (60%). The bench press (42%) and leg press (14%) were the most commonly studied exercises. The REPS ~ %1RM relationship for mean repetitions and standard deviation of repetitions were best described using natural cubic splines and a linear model, respectively, with mean and standard deviation for repetitions decreasing with increasing %1RM. More repetitions were evident in the leg press than bench press across the loading spectrum, thus separate REPS ~ %1RM tables were developed for these two exercises. Analysis of moderators suggested little influences of sex, age, or training status on the REPS ~ %1RM relationship, thus the general main model REPS ~ %1RM table can be applied to all individuals and to all exercises other than the bench press and leg press. More data are needed to develop REPS ~ %1RM tables for other exercises.

Short-Term Effects of Land-Based Versus Water-Based Resistance Training Protocols on Post-Exercise Hypotension in Normotensive Men: A Crossover Study

Considering that water immersion may acutely reduce blood pressure (BP) and that exercise may elicit positive post-exercise hypotension (PEH) responses, we aimed to analyze the presence of PEH in normotensive individuals and compare its magnitude between two resistance training sessions performed in aquatic or land environments. Ten physically active men (23.2 ± 3.1 years) performed the two training protocols in a randomized, counterbalanced fashion. BP measurements were performed for 30 min (at 5 min intervals) both prior to (resting) and after each of the protocols. No differences were observed between protocols at baseline (p > 0.05). Only the water-based resistance training protocol resulted in a systolic BP reduction from 10 to 20 min post-exercise (all p < 0.05) compared to baseline. Compared to the land-based session, systolic BP was lower in the water-based protocol from 10 to 25 min post-exercise (all p < 0.05). On the other hand, diastolic BP showed a similar PEH effect between water and land-based protocols for the entire 30 min post-session period (all p < 0.001). Our results suggest that water-based resistance training holds the potential as a nonpharmacological strategy to lower BP levels following exercise.

Effects of Different Models of Water-Based Resistance Training on Muscular Function of Older Women

PURPOSE

To compare the effects of three water-based resistance trainings on neuromuscular parameters of older women.

METHOD

Thirty-six women were randomized to groups: simple set of 30 seconds (1 × 30 s, 66.41 ± 4.71 years, n = 12), multiple sets of 10 seconds (3 × 10 s, 66.50 ± 4.74 years, n = 11), and simple set of 10 seconds (1 × 10 s, 65.23 ± 3.93 years, n = 13). Maximal isometric strength concomitantly with neuromuscular activity during extension and flexion knee was evaluated. In the same exercises, rate of force development at different time intervals was measured. Finally, functional capacity was assessed.

RESULTS

All trainings promoted similar improvements in the rate of force develpment of extension (effect size RFD 50 ms: 1 × 30 s .49, 3 × 10 s .67, 1 × 10 s .65; ES RFD 100 ms: 1 × 30 s .76, 3 × 10 s .80, 1 × 10 s .63; ES RFD 250 ms: 1 × 30 s .31, 3 × 10 s .49, 1 × 10 s .37) and flexion knee (ES RFD 50 ms: 1 × 30 s .59, 3 × 10 s .31, 1 × 10 s .48; ES RFD 100 ms: 1 × 30 s .41, 3 × 10 s .44, 1 × 10 s .42; ES RFD 250 ms: 1 × 30 s .57, 3 × 10 s .36, 1 × 10 s .43; ES RFD maximal: 1 × 30 s .63, 3 × 10 s .23, 1 × 10 s .26), however only the 3 × 10 s group improved the performance in the 8-foot up-and-go test (ES 3 × 10 s: .93, 1 × 30: .39, 1 × 10 s: .23). There was a maintenance of the isometric force and neuromuscular activity, except for the activity of the rectus femoris that showed an increase after training in all groups (ES 3 × 10 s: .04, 1 × 30: .36, 1 × 10 s: .50).

CONCLUSION

Water-based resistance training using simple or multiple sets promotes the same gains in rapid strength, however only multiple sets induced improvement on functional capacity.

Does Aerobic Exercise Impair Neuromuscular Function During Water-Based Resistance Exercises?

PURPOSE

The purpose of this study was to investigate the acute effects of water-based aerobic exercises on the performance of water-based resistance exercises by assessing kinematic parameters during protocols and neuromuscular responses after them.

METHOD

Ten women performed 2 water-based protocols (i.e., resistance and concurrent water-based exercises) on separate days. We evaluated isometric force and electromyographic signal (sEMG) before and after protocols and analyzed kinematic parameters during a water-based resistance exercise.

RESULTS

There was no significant difference between knee extension force production and sEMG from the vastus lateralis during the maximal voluntary contraction performed before and after the protocols. However, sEMG from the rectus femoris presented a significant difference between pretest and posttest measurements in both water-based protocols with greater values in the measurement after the end of the protocol (p = .046). The peak angular velocity of knee extension and mean angular velocity of knee extension and flexion showed similar values among the sets, with no difference between protocols. The peak angular velocity of knee flexion presented greater values in the water-based resistance exercises compared with the water-based concurrent protocol in the last set (p < .001).

CONCLUSION

The main impairment induced by the water-based concurrent exercises was the lower peak angular velocity in the knee flexors compared with water-based resistance exercises alone.