Validity of Rating of Perceived Exertion Scales in Relation to Movement Velocity and Exercise Intensity During Resistance-Exercise: A Systematic Review.

CONTEXT: Movement velocity (MV) may be a valid tool to evaluate and control the load in resistance training (RT). The rating of perceived exertion (RPE) also enables practical load management. The relationship between RPE and MV may be used to monitor RT intensity. OBJECTIVE: To evaluate the validity and practicality of RPE scales related to MV and training intensity in resistance exercise. We hypothesize a positive correlation among RPE, MV, and load intensity in RT. Therefore, RPE may serve as a supplementary indicator in monitoring RT load. DATA SOURCES: Boolean algorithms were used to search several databases (SPORTDiscus, EBSCO, PubMed, Scopus, and Google Scholar). STUDY SELECTION: Studies published from 2009 to 2023 included clinical trials (randomized or not) in healthy female and male subjects that analyzed the relationship between different RPE scales and MV in basic RT exercises. STUDY DESIGN: Systematic review. LEVEL OF EVIDENCE: Level 3. RESULTS: A total of 18 studies were selected using different RPE scales with reported MV training loads. Participants included RT and untrained male and female subjects (15-31 years old). Two RPE scales (OMNI-RES and repetitions in reserve) were used. The selected studies showed moderate positive correlations among these RPE scales, MV, and training load (eg, percentage of 1-repetition maximum [%1-RM]). In addition, equations have been developed to estimate %1-RM and MV loss based on the OMNI-RES scale. CONCLUSION: Studies show that RPE scales and MV constitute a valid, economic, and practical tool for assessing RT load progression and complementing other training monitoring variables. Exercise professionals should consider familiarizing participants with RPE scales and factors that might influence the perception of exertion (eg, level of training, motivation, and environmental conditions).

Effects of a Nonlinear Program on Different Health Parameters in the Elderly.

BACKGROUND: The aim of this research was to evaluate the impact of a nonlinear training program on visceral adipose tissue (VAT) and systolic (SBP) and diastolic (DBP) blood pressure, as well as the response of biochemical parameters such as fasting plasma glucose (FPG), total cholesterol (TC), high-density cholesterol (HDL-C), low-density cholesterol (LDL-C), and triglycerides (TG). HYPOTHESIS: The nonlinear periodized program would produce greater improvements in outcomes than the linear periodized training program. STUDY DESIGN: Randomized cross-sectional design. LEVEL OF EVIDENCE: Level 3. METHODS: Older adults with no previous training experience (10 male and 8 female [age, 64 ± 2.1 years; height, 165.12 ± 7.5 cm; body mass, 72.5 ± 11.4 kg; body max index, 26.5 ± 3.2 kg/m2]) were randomized to linear (n = 9, TT) or undulating (n = 9, UT) periodization. After a 3-week familiarization period, all participants performed 3 sessions of resistance training per week; 8 weeks of training were conducted for each group. Dual x-ray absorptiometry was used to measure VAT, and SBP and DBP were measured using an OMRON M3 digital automatic blood pressure monitor. Blood samples were collected between 8:00 a.m. and 9:30 a.m. after 12-hour overnight fasting. RESULTS: Both interventions significantly (P < 0.05) decreased FPG, TC, LDL-C, and TG. A significant decrease in SBP and DBP was observed only in the UT group (P < 0.05). No significant between-group differences in outcomes were observed (P > 0.5). However, the effect size was marginally more pronounced for all outcomes in the UT group. CONCLUSION: An undulating periodization program was effective in improving VAT, TC, LDL-C, FPG, HDL-C, TG, and blood glucose levels in older adults. CLINICAL RELEVANCE: Resistance training can be programmed in an undulating or traditional way in older adults based on improvements in health parameters, considering adherence and individual preferences.

Efficacy of progressive versus severe energy restriction on body composition and strength in concurrent trained women.

PURPOSE: This study evaluated the concurrent training (CT) effect in combination with either progressive energy restriction (PER) or severe energy restriction (SER) on body composition and strength-related variables in resistance-trained women. METHODS: Fourteen women (29.5 ± 3.8 years; 23.8 ± 2.8 kg·m-2) were randomly assigned to a PER (n = 7) or SER (n = 7) group. Participants performed an 8-week CT program. Pre- and post-intervention measures of fat mass (FM) and fat-free mass (FFM) were assessed by dual-energy X-ray absorptiometry and strength-related variables were assessed through 1-repetition maximum (in the squat and bench press) and countermovement jump. RESULTS: Significant reductions in FM were observed in PER and SER (Δ = - 1.7 ± 0.4 kg; P = < 0.001; ES = - 0.39 and Δ = - 1.2 ± 0.6 kg; P = 0.002; ES = - 0.20, respectively). After correcting FFM for fat-free adipose tissue (FFAT), no significant differences for this variable were found either in PER (Δ = - 0.3 ± 0.1; P = 0.071; ES = - 0.06) or in SER (Δ = - 0.2 ± 0.1; P = 0.578; ES = - 0.04). There were no significant changes in the strength-related variables. No between-group differences were found in any of the variables. CONCLUSION: A PER has similar effects to a SER on body composition and strength in resistance-trained women performing a CT program. Given that PER is more flexible and thus may enhance dietary adherence, it might be a better alternative for FM reduction compared to SER.

Is the Relationship between Acute and Chronic Workload a Valid Predictive Injury Tool? A Bayesian Analysis.

This study aimed to evaluate the relationship between injury risk, acute load (AL), acute chronic workload ratio (ACWR) and a new proposed ACWR. DESIGN: a retrospective cohort study of the year 2018 was conducted on Argentine first-division soccer players. PARTICIPANTS: Data from 35 players (age = 26.7 ± 4.71 years; height = 176.28 ± 6.09 cm; mass = 74.2 ± 5.27 kg) were recorded; 12 players' data were analyzed for 1 year, and 23 players' data were analyzed for 6 months. INTERVENTIONS: The mean difference of ACWR (MD = 0.22), high-density interval (HDI 95% = (0.07, 0.36)) and AL (MD = 449.23, HDI 95% = (146.41, 751.2)) between groups turned out to be statistically significant. The effect size between groups comparing ACWR and AL was identical (ES = 0.64). RESULTS: The probability of suffering an injury conditioned by ACWR or random ACWR was similar for all estimated quantiles, and the differences between them were not statistically significant. CONCLUSIONS: The ACWR ratio, using internal load monitoring, is no better than a synthetic ACWR created from a random denominator to predict the probability of injury. ACWR should not be used in isolation to analyze the causality between load and injury.

Comparison of post-activation performance enhancement (PAPE) after isometric and isotonic exercise on vertical jump performance.

PURPOSE: This study aimed to compare the post-activation performance enhancement (PAPE) induced by isometric and isotonic exercise on vertical jump performance. METHODS: 18 healthy trained men (25.8±2.7 years; 78.4±8.2 kg; 175.7±6.1 cm; 25.4±1.8 BMI; 126.72±10.8 kg squat 1-RM) volunteered for this study. They randomly performed two different PAPE protocols: Isotonic squats (ISOTS), which consisted of 2 sets of 3 repetitions at 75% of one-maximum repetition (1-RM); and isometric squats (ISOMS), which consisted of 2 sets of 4 seconds of submaximal (75% of 1-RM) isometric contraction at 90°-knee flexion. Countermovement jump (CMJ) height was tested at baseline and 4 minutes after each conditioning set. RESULTS: CMJ height significantly increased after set 1 in both PAPE protocols (ISOMS: p <0.001; ES = 0.34; ISOTS: p <0.001; ES = 0.24), with respect to the baseline jump. However, after set 2 no significant changes in CMJ height were observed for any protocol (ISOMS: p = 0.162; ES = 0.11; ISOTS: p = 0.976; ES = 0.06). No significant differences (p>0.05) were found between both isometric and isotonic exercise conditions. CONCLUSIONS: Despite both protocols showed similar PAPE effects on CMJ height after set 1, none of the protocols demonstrated greater efficacy in increasing subsequent performance in healthy trained men.

Sarcopenia: Etiology, Nutritional Approaches, and miRNAs.

Sarcopenia, an age-related decline in skeletal muscle mass and function, dramatically affects the quality of life. Although there is a consensus that sarcopenia is a multifactorial syndrome, the etiology and underlying mechanisms are not yet delineated. Moreover, research about nutritional interventions to prevent the development of sarcopenia is mainly focused on the amount and quality of protein intake. The impact of several nutrition strategies that consider timing of food intake, anti-inflammatory nutrients, metabolic control, and the role of mitochondrial function on the progression of sarcopenia is not fully understood. This narrative review summarizes the metabolic background of this phenomenon and proposes an integral nutritional approach (including dietary supplements such as creatine monohydrate) to target potential molecular pathways that may affect reduce or ameliorate the adverse effects of sarcopenia. Lastly, miRNAs, in particular those produced by skeletal muscle (MyomiR), might represent a valid tool to evaluate sarcopenia progression as a potential rapid and early biomarker for diagnosis and characterization.

Effects of a low-carbohydrate ketogenic diet on health parameters in resistance-trained women.

PURPOSE: The aim of this study was to evaluate the effect of a ketogenic diet on blood pressure, visceral adipose tissue (VAT), bone mineral content (BMC), and bone mineral density (BMD) in trained women. METHODS: Twenty-one resistance-trained women performed an 8-week resistance training program after a 3-week familiarization phase. Participants were randomly assigned to a non-ketogenic diet (n = 11, NKD) or ketogenic diet (n = 10, KD) group. Health parameters were measured before and after the nutritional intervention. Blood pressure was measured using a digital automatic monitor, while VAT, BMC, and BMD changes were measured by dual-energy X-ray absorptiometry. RESULTS: There was a significant reduction in systolic blood pressure in KD (mean ± SD [IC 95%], P value, Hedges' g; - 6.3 ± 6.0 [- 10.5, - 2.0] mmHg, P = 0.009, g = - 0.81) but not in NKD (- 0.4 ± 8.9 [- 6.8, 6.0] mmHg, P = 0.890, g = - 0.04). The results on VAT showed no changes in both groups. The KD showed a small favorable effect on BMD (0.02 ± 0.02 [0.01, 0.03] g·cm-2, P = 0.014, g = 0.19) while NKD did not show significant changes (0.00 ± 0.02 [- 0.02, 0.02] g·cm-2, P = 0.886, g = 0.01). No differences in group or in the time × group interaction were found in any of the variables. CONCLUSIONS: Consuming a low-carbohydrate high-fat KD in conjunction with a resistance training program might help to promote the improvement of health-related markers in resistance-trained women. Long-term studies are required to evaluate the superiority of a KD in comparison to a traditional diet.

Effects of heavy barbell hip thrust vs back squat on subsequent sprint performance in rugby players.

The objective of this research was to compare the effect of Post-Activation Performance Enhancement (PAPE) exerted on the back squat (BS) versus the barbell hip thrust (HT) on the sprint performance (5- and 10-m). 17 male amateur rugby players participated in the study (age 22.14 ± 2.52 years; body mass 81.06 ± 9.6 kg; height 1.78 ± 0.05 m). All participants performed a dynamic maximum strength test (3RM) in BS and HT at maximum speed. Two randomized sessions were performed inducing PAPE using BS or HT trough three series with three repetitions at 85% 1RM eight minutes before the sprint tests. An ANOVA of repeated measurement, found no differences in the time for 5-m (F = 0.398, P = 0.537, η2p = 0.024) or 10-m (F = 2.589, P = 0.127, η2p = 0.139). There were no significant differences in the Protocol effect between HT and BS in 5-m or 10-m (F = 2.963, P = 0.104, η2p = 0.156 and F = 1.472, P = 0.243 η2p = 0.084, respectively). There were also no differences in the Time x Protocol interaction at 5-m (F = 0.001, P = 0.976, η2p < 0.001) or 10-m (F = 4.174, P = 0.058, η2p = 0.207). The effect size obtained in the results of the sprint tests was small in both exercises (ES < 0.2). None of the BS or HT exercises performed with heavy load induced a significant PAPE phenomenon on the ability to sprint in rugby players.

Comparison of blood lactate and perceived exertion responses in two matched time-under-tension protocols.

PURPOSE: The aim of this study was to compare the concentration of blood lactate [bLa-] and the subjective perception of exertion of trained men in a moderate repetition protocol (MRP) versus a high repetition protocol (HRP) equated for time under tension. METHODS: A sample of 40 healthy young men (aged, 23.2 ± 4.0 years; height, 177.3 ± 7.0 cm; BMI, 24.3 ± 2.2) performed two sessions of 8 sets of bicep curls with a one-week recovery interval between the trials. In the HRP protocol, 20 repetitions were performed with a cadence of 2 seconds of eccentric and 1 second of concentric, while in the MRP protocol 10 repetitions were performed with 4 seconds of eccentric and 2 seconds of concentric. Cadences were controlled by a metronome. At the beginning and end of each of the sessions, blood lactate was taken at 2, 15, and 30 minutes, and rating of perceived exertion (OMNI-RES) was assessed immediately after completion of each session. RESULTS: There were [bLa-] differences between protocols in the MRP 2 min, (5.2 ±1.4); 15 min, (3.2 ±1.2); 30 min, (1.9 ±0.6); p< 0.05, and the HRP 2 min, (6.1 ±1.6); 15 min, (3.7 ±1.1); 30 min, (2.2 ±0.6); p<0.01. OMNI-RES was higher in HRP, (8.8 ±0.7) than in MRP, (7.7 ±0.9). Additionally, a correlation was found between the RPE and [bLa-] values in the HRP protocol (rs = 0.35, p < 0.01). CONCLUSIONS: Training protocols with high times under tension promote substantial increases in metabolic stress, however, our findings indicate that HRP generates more [bLa-] than MRP. In addition, there were higher RPE values in the HRP protocol compared to MRP in single-joint exercises.

Correction to: Effectiveness of combining microcurrent with resistance training in trained males.

The original version of this article unfortunately contained a mistake.

Effectiveness of combining microcurrent with resistance training in trained males.

INTRODUCTION: Microcurrent has been used to promote tissue healing after injury or to hasten muscle remodeling post exercise. PURPOSE: To compare the effects of resistance training in combination with either, microcurrent or sham treatment, on-body composition and muscular architecture. Additionally, changes in performance and perceived delayed onset muscle soreness (DOMS) were determined. METHODS: Eighteen males (25.7 ± 7.6 years) completed an 8-week resistance training program involving 3 workouts per week (24 total sessions) wearing a microcurrent (MIC, n = 9) or a sham (SH, n = 9) device for 3-h post-workout or in the morning during non-training days. Measurements were conducted at pre and post intervention. RESULTS: Compared to baseline, both groups increased (p < 0.05) muscle thickness of the elbow flexors (MIC + 2.9 ± 1.4 mm; SH + 3.0 ± 2.4 mm), triceps brachialis (MIC + 4.3 ± 2.8 mm; SH + 2.7 ± 2.6 mm), vastus medialis (MIC + 1.5 ± 1.5 mm; SH + 0.9 ± 0.8 mm) and vastus lateralis (MIC + 6.8 ± 8.0 mm; SH + 3.2 ± 1.8 mm). Although both groups increased (p < 0.01) the pennation angle of vastus lateralis (MIC + 2.90° ± 0.95°; SH + 1.90° ± 1.35°, p < 0.01), the change measured in MIC was higher (p = 0.045) than that observed in SH. Furthermore, only MIC enlarged (p < 0.01) the pennation angle of brachialis (MIC + 1.93 ± 1.51). Both groups improved (p < 0.05) bench press strength and power but only MIC enhanced (p < 0.01) vertical jump height. At post intervention, only MIC decreased (p < 0.05) DOMS at 12-h, 24-h, and 48-h after performing an exercise-induced muscle soreness protocol. CONCLUSION: A 3-h daily use of microcurrent maximized muscular architectural changes and attenuated DOMS with no added significant benefits on body composition and performance.