Modulation of HSP27 and inflammatory cytokines by different resistance training protocols in postmenopausal women

The purpose of this study is to measure the acute effects of exercise variability on muscle thickness and physical performance after two resistance training (RT) protocols using the same or different exercises in recreationally-trained subjects. Fifteen resistance-trained men (23.1 ± 2.6 years, 83.4 ± 16.6 kg, 173.5 ± 8.3cm) performed one of two RT protocols: SINGLE: six sets of 10RM/two-minutes rest of the unilateral biceps curl exercise using cables or MIX: six sets of 10RM/two-minutes rest for the unilateral biceps curl exercises (cable: three sets and dumbbells: three sets, randomly). Muscle thickness (MT) and peak force (PF) were measured ten-minutes before (control), pre-RT session, and post-RT (immediately after and 15-minutes after). All acute RT variables were measured during both RT protocols: the maximal number of repetitions (MNR), the total number of repetitions (TNR), time under tension (TUT), and rating of perceived exertion (RPE). Two-way ANOVA (2 x 4) was used to test differences between RT protocol (SINGLE and MIX) and time (control, pre-test, post0, and post15) for MT and PF. Two-way ANOVAs (2 x 6) were used to test differences between RT protocol (SINGLE and MIX) and sets for MNR, RPEset, and TUT. For PF and MT, there were significant differences in time for both RT protocols (p < 0.05), however, there were not statistical differences between RT protocols. For MNR, RPEset, and TUT, there were significant differences in time (p < 0.05), however, there were not statistical differences between RT protocols. In conclusion, both RT protocols induced a similar increase in MT for elbow flexors and a reduction in peak force.

The primary purpose of this study was to evaluate acute dose response of different intensities with total volume equalized during the abdominal crunch exercise on muscle thickness, echo-intensity, peak force, time under tension, total load lifted, and perception of effort in recreationally-trained participants. Fifteen resistance-trained participants (23 ± 3 years) performed the abdominal crunch exercise in one of two different resistance training (RT) protocols in a randomized order: RT4×10RM (4 sets of 10RM / 1-min rest) or RT1×40RM (1 set of 40RM). Muscle thickness (MT), echo-intensity (EI), peak force (PF), time under tension (TUT), total load lifted (TLL), and session rating of perceived exertion (sRPE) were measured pre-test and post-test (0-min and 15-min). Two-way repeated-measures ANOVAs (2 × 3) were used to test differences between RT protocols (RT4×10RM and RT1×40RM) and time (pre-test, post-0, and post-15) for MT, EI, and PF. Paired t-test was used to compare RT protocols for sRPE, TLL, and TUT. For MT, there were significant differences for RT4×10RM between pre-x post-0 (p = 0.011), pre-x post-15 (p < 0.001), and post-0 × post-15 (p = 0.02); and for RT1×40RM between pre-x post-0 (p < 0.001) and pre-x post-15 (p = 0.003). For EI, there was a significant difference for RT4×10RM between pre-x post-0 (p = 0.002). For sRPE, there was no significant difference between RT protocols. For TLL and TUT, there were significant differences between RT protocols (p < 0.05). In conclusion, both RT protocols (RT4×10RM and RT1×40RM) induced similar increases in MT but not for EI. TLL and TUT were higher for RT4×10RM. PF and sRPE were similar between RT protocols.

Objective: To systematically review the effects of different resistance training (RT) protocols on bone mineral density (BMD) in postmenopausal women.Methods: Randomized controlled trials (RCTs) on the resistance training in improving bone mineral density for postmenopausal women were searched in databases including ProQuest, PubMed, Cochrane Library, Embase, and Web of Science. The retrieval time range was from the establishment of the database to May 2022. The included literature was independently screened and relevant data was extracted by two reviewers. The systematic review followed the Joanna Briggs Institute (JBI) methodology for reviews of quantitative evidence. Quality of risk was assessed using the Physical Therapy Evidence Database (PEDro) scale, risk of bias was assessedusing the Cochrane RoB2 tool and a network Meta-analysis was performed on the data using Stata 16.0.Results: A total of 19 studies, which included 919 subjects, were eventually acquired. The results of the network Meta-analysis showed that moderate intensity resistance training was superior in improving lumbar spine bone mineral density (LS BMD) and femoral neck bone mineral density (FN BMD) compared to the control group (as per usual daily life), with a statistically significant difference (p < 0.05). There was, however, no statistically significant difference between the groups in terms of increasing total hip bone mineral density (TH BMD) and trochanter bone mineral density (Troch BMD), although moderate intensity training tends to increase bone mineral density (p > 0.05). In addition, when training frequency is taken into consideration, 3 days/week of moderate intensity training (3MI) was superior to 2 days/week (2MI) in improving lumbar spine bone mineral density , and moderate intensity training was superior to low and high intensity resistance trainings at training frequency of 3 day/week, with statistically significant differences (p < 0.05). The cumulative probability ranking results indicated that 3MI was the optimal option in improving lumbar spine, femoral neck, total hip and Troch bone mineral density. Subgroup analyses combining interventions time showed that for lumbar spine and femoral neck bone mineral density, 3MI protocol with intervention duration within 1 year (≤48 weeks) had a significant advantage over other interventions, while this advantage was no longer significant with the intervention duration of more than 1 year (>48 weeks).Conclusion: Current evidence shows that moderate intensity resistance training for 3 days/week can be preferred clinically to improve bone mineral density in postmenopausal women, and it is recommended that the duration of the same training should not exceed 1 year. Nevertheless, more high-quality studies are needed to verify the above conclusion.

The purpose of this study was to measure the acute effects of resistance training (RT) protocols with a different number of sets and non-equalized volume on muscle thickness, peak force, and physical performance in recreationally-trained participants. Fifteen participants performed the unilateral biceps curl exercise in four different RT protocols (G4: 4 sets of 10RM, G8: 8 sets of 10RM, G12: 12 sets of 10RM, and G16: 16 sets of 10RM). The average number of repetitions (ANR), the total number of repetitions (TNR), time under tension (TUT), muscle thickness (MT), peak force (PF), and rating of perceived exertion (sRPE) were measured pre-test and post-test. ANOVAs were used to test differences between all dependent variables. For ANR, there were differences between G4xG8, G4xG12, and G4xG16 and between RT protocols for TNR (p&lt;0.05). There were differences for all RT protocols and between G12 and G4, G8, and G16 for TUT (p&lt;0.05). MT increased and PF decreased for all RT protocols (p&lt;0.001). In conclusion, G8, G12, and G16 showed lower ANR than G4, TNR increased with increasing sets, and TUT increased in all RT protocols. PF decreased with increasing sets and all RT protocols increased MT. The sRPE was similar between RT protocols.

Pérez-Castilla, A, García-Pinillos, F, Miras-Moreno, S, Ramirez-Campillo, R, García-Ramos, A, and Ruiz-Alias, SA. Selective effect of different high-intensity running protocols on resistance training performance. J Strength Cond Res 37(6): e369-e375, 2023-This study aimed to explore the acute effect of 2 high-intensity running protocols (high-intensity interval training [HIIT] and sprint interval training [SIT]) on resistance training (RT) performance and their combined effect on the lower-body maximal neuromuscular capacities. Eighteen healthy subjects randomly completed 3 experimental protocols: only RT, HIIT + RT, and SIT + RT. Characteristics of the RT protocol include 3 back-squat sets of 10 repetitions or 20% velocity loss against 60% of 1 repetition maximum with 3 minutes of interset rest. Characteristics of the high-intensity running protocols include HIIT (4 intervals of 4 minutes at ∼110% of functional threshold power with 3 minutes of interinterval rest) and SIT (6 all-out sprints of 30 seconds with 4 minutes and 24 seconds of interinterval rest). The force-velocity relationship (maximal values of force [ F0 ], velocity [ v0 ], and power [P max ]) was evaluated at the beginning and at the end of each experimental protocol. The number of back-squat repetitions ( p = 0.006; effect size [ES] = -0.96), fastest velocity ( p = 0.003; ES = -0.63), and average velocity ( p = 0.001; ES = -0.73) were lower for the SIT + RT protocol compared with the RT protocol, but no significant differences were observed between the RT and HIIT + RT ( p ≥T0.057; ES ≤.-0.46, except -0.82 for the number of back-squat repetitions) and HIIT + RT and SIT + RT ( p ≥T0.091; ES .0-0.35) protocols. The 3 protocols induced comparable decreases in v0 and P max ( F(2,34) 2,0.96; p ≥ 0.393), but F0 tended to decrease after the SIT + RT protocol and to increase after the RT and HIIT + RT protocols ( F(2,34) = 4.37; p = 0.035). Compared with RT alone, the data suggest that SIT deteriorates RT quality and F0 capacity more than long-interval HIIT.

Exercise training induces beneficial arterial adaptations in healthy individuals. The effects of exercise on arterial structure and function in healthy participants have been studied predominantly using cross-sectional comparisons of trained athletes and untrained healthy control participants. Few studies have investigated arterial adaptations with a randomized longitudinal exercise training design, which could account for within-subject responses to either endurance- or resistance-training stimuli. Comparisons between the long-term effects of endurance training (ET) versus resistance training (RT) may highlight structural and functional adaptations in the arteries. Spence et al. (2013) recently implemented a 6-month, prospective randomized longitudinal study to determine the effects of ET and RT on conduit artery adaptations in healthy humans. Their study revealed a divergent response in conduit arterial structural and functional adaptations following RT relative to ET. In the periphery, while RT training increased arterial diameter and function in the brachial artery, it did not elicit any changes in the femoral artery. Conversely, while ET training increased arterial diameter and function in the femoral artery, it did not elicit any changes in the brachial artery. Nonetheless, central arterial adaptations were present following both RT and ET training as measured by a decrease in carotid artery wall thickness. Their novel findings ultimately suggest that either exercise modality may be beneficial in reducing cardiovascular risk; however, exercise modality may influence specific peripheral arterial adaptations. Spence et al.'s study design provided a novel approach to evaluate arterial structure and function in RT and ET. Their protocols involved progressively increasing RT and ET workloads, thereby reducing the risk of participant drop-out resulting from injuries or fatigue. The RT and ET protocols were standardized to time, rather than energy expenditure. This may have led to differences in training workload and varying arterial adaptations. More specifically, ET was performed 3 days per week and included low- to moderate-intensity exercises focused on the lower body (i.e. walking, jogging and stretching). Low-volume sprint interval training (SIT; i.e. 30 s intervals interspersed with recovery) may further improve endothelial function and arterial distensibility, providing an attractive alternative to elicit arterial adaptations (Rakobowchuk et al. 2008). In comparison, RT was based on upper- and lower-body Olympic weightlifting exercises performed 3 days per week. Localized brachial artery adaptations occurred following RT, which may be related to consistent hand-grip during RT. Future studies are needed to determine the relative contribution of isometric hand-grip stimuli on conduit arterial adaptations. Investigations of exercise-induced arterial adaptation have focused predominantly on short-term (<12 weeks) training protocols. Notably, short-term exercise can produce both functional and structural changes in the conduit arteries, in part due to enhanced nitric oxide (NO) and endothelial nitric oxide synthase (eNOS) bioactivity (Tinken et al. 2008). Tinken et al. (2008) showed that functional changes in conduit arteries occur rapidly, with significant changes in brachial and popliteal artery flow-mediated dilatation occurring after just 2 weeks of endurance exercise training. Furthermore, it has been previously demonstrated that a 12-week endurance exercise intervention in previously sedentary healthy men resulted in significant increases in femoral artery lumen diameter (Dinenno et al. 2001). Few studies have investigated arterial adaptations with a longitudinal exercise training design to account for individual responses over an extended duration of training stimuli. Although arterial measures were obtained by Spence et al. (2013) prior to and following the 6-month intervention, a 3-month measure of arterial function and structure may have provided more insight into the arterial adaptations to the training stimuli. The inclusion of a 3 month data collection time point in the current study would have enabled comparisons between Spence et al.'s study and prior findings, as these other studies have used shorter-term exercise protocols and also observed significant arterial changes. Potential sex differences may limit the generalizability of the study findings, as Spence et al. (2013) used only male participants to examine arterial adaptation to RT or ET. In a recent review (Orshal & Khalil, 2004), sex differences in arterial tone were reported and attributed to direct arterial effects of sex hormones. Oestrogen and testosterone each bind to specific hormone receptors in the arteries. Oestrogen specifically induces vasodilatory effects via activation of eNOS and up-regulation of NO. Interestingly, total NO production and NO release from the endothelium was shown to be greater in premenopausal women than in men (Orshal & Khalil, 2004). Therefore, females may demonstrate improved adaptation to increased levels of shear stress than males. Sex differences may interact and mediate the relationship between changes in arterial function and structure following exercise training. Study findings (Spence et al. 2013) support the implementation of supervised long-term RT and ET programmes to improve arterial function among healthy participants. Long-term arterial adaptations following RT and ET programmes within clinical cohorts remain unclear. Future research may also include the role of RT and ET on arterial function within cardiovascular disease cohorts, including peripheral vascular disease, Kawasaki disease and Marfan syndrome cohorts. These clinical populations have characteristic deficiencies in arterial structure and function with limited research related to the benefits of exercise training. In fact, RT and ET may result in clinically relevant improvements in arterial structure and function, more so than healthy participants. Furthermore, RT protocols involving Olympic weightlifting may not be practical for a clinical cohort. Future studies should investigate more traditional RT training as it may be more suitable for the clinical population. Although the RT and ET protocols employed in the current study (Spence et al. 2013) may indeed elicit arterial benefits among clinical cohorts, continuous ET and traditional RT protocols may be too time consuming. In contrast, low-volume, high-intensity endurance exercise is an alternative approach proposed to improve arterial function and thus decrease cardiovascular risk (Gibala et al. 2012). In conclusion, this study (Spence et al. 2013) provided new insight into the longer-term effects of RT and ET on arterial structure and function. These novel findings need to be substantiated with future studies in healthy females and clinical cardiovascular cohorts to fully determine the clinical relevance of RT and ET on arterial structure and function.

Circulating microRNAs (c-miRNAs) in human plasma have been described as a potential marker of exercise. The present study investigated the effects of three acute resistance training (RT) protocols on the time-course changes of the c-miRNAs profiles in young males. The subjects (n = 45) were randomly divided into three groups: muscular strength endurance (SE), muscular hypertrophy (MH) and maximum strength (MS). Venous blood samples were obtained before exercise and immediately, 1 h and 24 h after each RT protocol to assess the following biological parameters: c-miRNAs, anabolic and catabolic hormones, inflammatory cytokines and muscle damage markers. The results revealed that the levels of two c-miRNAs (miR-208b and miR-532), six c-miRNAs (miR-133a, miR-133b, miR-206, miR-181a, miR-21 and miR-221) and two c-miRNAs (miR-133a and miR-133b) changed significantly in response to the SE, MH and MS protocols (p < 0.05), respectively. The nature and dynamic processes of the c-miRNAs response were likely influenced by the RT modality and intensity. Moreover, miR-532 was negatively correlated with insulin-like growth factor-1 and positively correlated with interleukin-10, whereas miR-133a was negatively correlated with cortisol and positively correlated with testosterone/cortisol. These findings suggest that these c-miRNAs may serve as markers for monitoring the RT responses.

Introduction. Studies have revealed that the anabolic effect of irisin on bone is mediated by an increase in alkaline phosphatase. However, few studies have investigated the interactive effect of irisin on alkaline phosphatase after exercise training. Therefore, the present study aimed to compare the impact of endurance and resistance training protocols on serum irisin concentration and total alkaline phosphatase activity in sedentary obese women. Material and methods. Forty-five sedentary obese women (age: 48.96 ± 5.2 years, body mass index 32.24 ± 3.76 kg/m2) were randomly assigned to control, endurance, and resistance groups. Endurance (45 to 75 minutes at an intensity corresponding to 50 to 80% of heart rate reserve) and resistance exercise training (3 sets, 10-15 repetitions at an intensity corresponding to 50 to 65% of one-repetition maximum) were conducted for 8 weeks, 3 days per week. Maximal oxygen consumption (VO2max) was estimated using the modified Bruce protocol treadmill test. Fasting blood samples were taken before the first and 48-hr after the last exercise training sessions. The serum concentrations of irisin and total alkaline phosphatase activity were measured using the sandwich ELISA method and photo-metric method, respectively. Results. Both endurance and resistance exercise training protocols caused a significant reduction in BMI and BFP of obese women. In contrast, VO2max significantly increased after both exercise training protocols. However, neither endurance nor resistance training protocols had a significant impact on the serum concentrations of irisin and total alkaline phosphatase activity. No significant inter-group differences were observed between the subjects’ BMI, BFP, VO2max, total alkaline phosphatase, and irisin at the end of protocols. Conclusions. The finding of the current study revealed that neither of the training protocols had a significant impact on bone anabolic parameters. However, performing these types of exercise is suggested for weight management in obese women.

Establishing an ideal resistance training (RT) protocol for hypertensive individuals has been a challenging task, given the many variables that should be considered in these protocols. In general, the protocols established for hypertensive individuals involve the use of lower loads and a higher number of repetitions. However, recent evidence has shown that this approach might generate negative effects on cardiovascular parameters, especially in the short term, which may indicate a potential risk to participants. In contrast, the use of higher loads but with a reduced number of repetitions does not seem to cause such overload to the cardiovascular system and have been shown to promote comparable gains in variables such as strength, body composition, balance and quality of life. PURPOSE: Analyze the effects of different resistance training protocols with lower and higher loads on cardiovascular parameters in hypertensive women. METHODS: A randomized crossover design clinical trial was conducted with 20 postmenopausal hypertensive women who underwent a control session and two RT protocols involving 6 and 15 repetition maximum (RM). The cardiovascular variables were collected pre, immediately post, 1 h post, and 24 h post each protocol. Repeated-measures ANOVA was used. RESULTS: The HR indices were higher in 15RM protocol immediately and 1 hour after the exercise (86.55±12.81; 75.96±11.51) when compared with control (67.14±7.38; 66.01±8.88) and 6RM (78.56±9.73; 71.29±9.40) sessions (p<0.05). The rate-pressure product indices that represent the myocardial workload also were higher in 15RM protocol immediately (12089.59±3022.77) and persisted in 1 hour after (9947.44±2184.58) the exercise when compared with control (8830.83±1394.09; 8800.71±1498.79) and 6RM (11002.58±1986.82; 9226.33±1604.68) sessions (p<0.05). CONCLUSIONS: Performing high intensity RT with lower loads and a higher number of repetitions seems to promote higher heart rate and rate-pressure product, which may be related to an increased cardiovascular stress. Although the 6RM protocol also raises these parameters immediately after, these changes were not evident within 1 hour and may serve as an indication that the use of high loads may be safe to the cardiovascular system in hypertensive individuals.

BackgroundIn this study, we investigated the effects of resistance training protocols with different loads on muscle hypertrophy and strength.MethodsTwenty-one participants were randomly assigned to 1 of 3 (n = 7 for each) resistance training (RT) protocols to failure: High load 80 % 1RM (8–12 repetitions) (H group), low load 30 % 1RM (30–40 repetitions) (L group) and a mixed RT protocol (M group) in which the participants switch from H to L every 2 weeks. RT consisted of three sets of unilateral preacher curls performed with the left arm 3 times/week with 90 s rest intervals between sets. The right arm served as control. Maximum voluntary contraction (MVC) of the elbow flexors (elbow angle: 90°) and rate of force development (RFD, 0–50, 50–100, 100–200 and 200–300 ms) were measured. Cross-sectional area (CSA) of the elbow flexors was measured via magnetic resonance imaging (MRI). All measurements were conducted before and after the 8 weeks of RT (72–96 h after the last RT). Statistical evaluations were performed with two-way repeated measures (time × group).ResultsAfter 8 weeks of 3 weekly RT sessions, significant increases in the left elbow flexor CSA [H: 9.1 ± 6.4 % (p = 0.001), L: 9.4 ± 5.3 % (p = 0.001), M: 8.8 ± 7.9 % (p = 0.001)] have been observed in each group, without significant differences between groups. Significant changes in elbow flexor isometric MVC have been observed in the H group (26.5 ± 27.0 %, p = 0.028), while no significant changes have been observed in the M (11.8 ± 36.4 %, p = 0.26) and L (4.6 ± 23.9 %, p = 0.65) groups. RFD significantly increased during the 50–100 ms phase in the H group only (p = 0.049).ConclusionsWe conclude that, as long as RT is conducted to failure, training load might not affect muscle hypertrophy in young men. Nevertheless, strength and RFD changes seem to be load-dependent. Furthermore, a non-linear RT protocol switching loads every 2 weeks might not lead to superior muscle hypertrophy nor strength gains in comparison with straight RT protocols.

Purpose: This study investigated the impact of two different resistance training (RT) protocols on cardiac autonomic modulation during exercise recovery in trained individuals. It was hypothesized that a hypertrophic resistance training program would induce more significant stress and negatively affect cardiac autonomic modulation compared to a power/force resistance training program. Methods: Six healthy, trained participants (aged 18–40) were randomized in a crossover and controlled pilot study. Participants performed two RT protocols: (i) three sets of 10 repetitions with 85% of 10 RM, 60 s inter-set rest (3x1060s) and (ii) eight sets of three repetitions with 85% of 3 RM, 120 s inter-set rest (8x3120s). Heart rate variability (HRV) was measured before and 30 min after each RT session. Results: Significant reductions in HRV parameters (RMSSD, HF, and SD1) were observed following the 3x1060s protocol (hypertrophic design) compared to baseline. Conversely, the 8x3120s (power/force design) protocol did not show significant changes in HRV parameters. A significant interaction effect for time and RT protocol was found for all HRV measures with more significant reductions observed after 3x1060s compared to 8x3120s. Conclusions: The hypertrophic RT session (3x1060s) significantly reduced HRV parameters, suggesting higher physiological stress and potentially negative implications for cardiac autonomic recovery than the power/force RT session (8x3120s). These findings highlight the importance of considering exercise intensity and protocol design to manage cardiac autonomic stress during resistance training.

This meta-analysis synthesized current evidence from 24 clinical trials to evaluate the impact of different resistance training modes on postmenopausal bone loss. Exercise interventions were categorized into two training modes, namely resistance-alone versus combined resistance training protocols. The combined resistance training protocols were defined as the combination of resistance training and high-impact or weight-bearing exercise. The results suggested that the combined resistance training protocols were effective in improving bone mineral density (BMD) at the femoral neck and lumbar spine. The current meta-analysis aimed to examine the effects of combined resistance and resistance-alone training protocols on the preservation of femoral neck and lumbar spine BMD in postmenopausal women. An electronic database search was conducted in PubMed, EMBASE, SPORTDiscus, Web of Science, and ProQuest up to March 1, 2014 for the influence of resistance exercise on BMD in postmenopausal women. The study quality was evaluated. The effect sizes were estimated in terms of the standardized mean difference (SMD). A subgroup analysis was conducted by exercise categories. Twenty-four studies were included in the overall analysis of skeletal response to resistance exercise. The between-study heterogeneity was evident for the hip (I (2) = 46.5%) and spine (I (2) = 62.3%). The overall analysis suggested that resistance training significantly increased femoral neck BMD (SMD = 0.303, 95% confidence interval (95% CI) = 0.127-0.479, p = 0.001) and lumbar spine BMD (SMD = 0.311, 95% CI = 0.115-0.507, p = 0.002) in postmenopausal women. However, subgroup analysis indicated that combined resistance training programs significantly affected both the hip BMD (SMD = 0.411, 95% CI = 0.176-0.645, p = 0.001) and spine BMD (SMD = 0.431, 95% CI = 0.159-0.702, p = 0.002), whereas resistance-alone protocols only produced nonsignificant positive effects both on the femoral neck and lumbar spine BMD. Combined resistance exercise protocols appear effective in preserving femoral neck and lumbar spine BMD in postmenopausal women, whereas resistance-alone protocols only produced a nonsignificant positive effect.

Margoni, M, Bochicchio, G, Ferrari, L, and Pogliaghi, S. Muscle soreness and neuromuscular fatigue after three different resistance exercise protocols: Comparison between men and women. J Strength Cond Res 39(6): 625-633, 2025-This study evaluated the sex-related differences in the magnitude and time course of muscle soreness and neuromuscular fatigue after 3 different resistance training (RT) protocols, in both the upper and lower body. Sixteen recreational resistance-trained women ( n = 7) and men ( n = 9) performed 3 RT protocols, in randomized order as either power (POW, 4 × 5 at 50% 1 repetition maximum [1RM]), strength (STR, 4 × 2 at 90% 1RM), and hypertrophy (4 × 10 at 70% 1RM), involving 2 main exercises (back squat and bench press) at aim-specific training load, and 4 complementary exercises. Visual analog scale and load cell (1,000 Hz, AEP transducer, Italy) were used to assess muscle soreness and changes in maximal peak force, respectively, of upper and lower body pre-, post-, 24 h, 48, and 72 h after each protocol. Three-way RM ANOVA was run to compare muscle soreness and neuromuscular fatigue of the upper and lower body between sexes, within protocols and time. Men and women showed similar changes in muscle soreness and neuromuscular fatigue across all protocols and body parts ( p > 0.05). Moreover, both sexes exhibited higher neuromuscular fatigue in the lower body than the upper body, across all protocols ( p < 0.05). These results suggest that men and women show similar kinetics in muscle soreness and neuromuscular fatigue after 3 different RT protocols, with a greater impact experienced in the lower body. Therefore, designing RT programs on sex-specific performance kinetics may not be essential, although increasing upper body exercises volume and frequency can benefit both sexes.

The objective of this study was to investigate the equivalence between resistance training protocol with self-selected intensity (RT-SSI) and resistance training protocol with imposed intensity (RT-II) in postmenopausal women. A randomized study involving 49 women was carried out. Participants were randomly assigned to either RT-II or RT-SSI. The RT-II group performed with a training load initially imposed at 60%, increasing to the 70%-85% range of one maximum repetition (1RM), while the RT-SSI group performed with a training load self-selected by the volunteers for 12 weeks. Muscle strength (1RM), the 6-minute walk test (6MWT), and body composition were assessed before and after the intervention. Both groups showed significant improvements in strength (P<0.001), muscle mass (P=0.027), and physical performance (P=0.023) after the 12-week intervention. However, there were no significant differences in the effects of the time/group interaction on muscle mass (P=0.750), strength (P=0.651), and physical performance (P=0.724). The equivalence analysis indicated Cohen d values for the effect estimate above the lower limit value for equivalence (d=-0.5). These results suggest that there is no evidence of the inferiority of RT-SSI in relation to RT-II for muscle mass, muscle strength, and physical performance. However, equivalence between interventions was not established, as the upper limits for equivalence were exceeded by the 90% CI. Our findings indicated that RT-SSI is comparable to RT-II in terms of muscle mass, muscle strength, and physical performance gains in postmenopausal women.

To evaluate the interference effects of various resistance-training (RT) protocols on rowing ergometer performance. Fourteen semiprofessional male rowers randomly completed 5 protocols in separate sessions: (1)control-no RT session was performed, (2)upper-body high-fatigue-4 sets to failure during the bench pull exercise, (3)upper-body low-fatigue-4 sets of 6 repetitions during the bench pull exercise, (4)lower-body high-fatigue-4 sets to failure during the leg-press exercise, and (5)lower-body low-fatigue-4 sets of 6 repetitions during the leg-press exercise. All sets were performed against the 12-repetition-maximum load with 2minutes of interset rest. Following the completion of the protocols, subjects performed an all-out 1000-m rowing ergometer test. Compared with the control condition, rowing ergometer performance was not significantly affected after the low-fatigue RT protocols (upper body: P ≥ .487; Δ = 0.0%-0.2%; lower body: P ≥ .200; Δ = -0.2%-0.5%), while it significantly declined following high-fatigue RT protocols (upper body: P ≤ .001; Δ = 1.0%-2.0%; lower body: P ≤ .002; Δ = 2.1%-2.5%). The average heart rate was significantly lower for the control condition compared with all RT protocols (P ≤ .043; Δ = 1.0%-1.5%). To minimize interference on rowing performance, coaches should prioritize the level of effort in RT protocols over specific exercises, specifically avoiding high-fatigue protocols that lead to failure before rowing practice.