Maximum Number Of Repetitions Research Articles

Could a Habitual Sleep Restriction of One-two Hours Be Detrimental to the Benefits of Resistance Training?

The absence or decrease in sleep time can affect different mechanisms associated with changes in body composition and physical exercise performance. However, it is unclear in the literature how chronically sleep-restricted individuals respond to strength training. Thus, this study aimed to evaluate the effects of reducing between one and two hours of recommended sleep time (7 hours) on the response to resistance training. The study included 12 subjects who slept on average 2 hours less than the recommended 7 hours per day (42 ± 8 years; 84.9 ± 11.6 kg; 27.9 ± 3.5 kg/m 2 ; 6:17 ± 22 total sleep time/day and 5: 47 ± 29 sleep time/night) and 12 subjects with recommended sleep time (38 ± 11 years; 78.3 ± 9.5 kg; 25.1 ± 3.5 kg/m 2 ; 7:47 ± 38 total sleep time/day and 7:16 ± 54 sleep time/night) and a control group (42 ± 7 years; 81 ± 12.2 kg; 26.2 ± 4.0 kg/m 2 ; 7:30 ± 40 total sleep time/day and 7: 17 ± 51 sleep time/night) that did not perform resistance training. A total of 16 resistance training sessions were performed, 3 times a week (Sessions= 4 exercises; 2 sets; maximum repetitions to failure). The maximum number of repetitions, arm circumference, and arm muscle area increased, while triceps skinfold decreased after training in the experimental groups ( p < 0.05), with no changes for the control group. There was no difference in muscle mass, body mass index, or sleep variables (sleep time, latency, efficiency) after the training period in either group (p> 0.05). Thus, the chronic 1-2-hour reduction in average recommended sleep time was not able to affect the positive effects of resistance training.

Narrowband Internet of Things via Low Earth Orbit Satellite Networks: An Efficient Coverage Enhancement Mechanism Based on Stochastic Geometry Approach.

With the development of IoT technology and 5G massive machine-type communication, the 3GPP standardization body considered as viable the integration of Narrowband Internet of Things (NB-IoT) in low Earth orbit (LEO) satellite-based architectures. However, the presence of the LEO satellite channel comes up with new challenges for the NB-IoT random access procedures and coverage enhancement mechanism. In this paper, an Adaptive Coverage Enhancement (ACE) method is proposed to meet the requirement of random access parameter configurations for diverse applications. Based on stochastic geometry theory, an expression of random access channel (RACH) success probability is derived for LEO satellite-based NB-IoT networks. On the basis of a power consumption model of the NB-IoT terminal, a multi-objective optimization problem is formulated to trade-off RACH success probability and power consumption. To solve this multi-objective optimization problem, we employ the Non-dominated Sorting Genetic Algorithms-II (NSGA-II) method to obtain the Pareto-front solution set. According to different application requirements, we also design a random access parameter configuration method to minimize the power consumption under the constraints of RACH success probability requirements. Simulation results show that the maximum number of repetitions and back-off window size have a great influence on the system performance and their value ranges should be set within [4, 18] and [0, 2048]. The power consumption of coverage enhancement with ACE is about 58% lower than that of the 3GPP proposed model. All this research together provides good reference for the scale deployment of NB-IoT in LEO satellite networks.

The Effect of Oral Adenosine Triphosphate (ATP) Supplementation on Anaerobic Exercise in Healthy Resistance-Trained Individuals: A Systematic Review and Meta-Analysis.

Adenosine triphosphate (ATP) is an energy and signaling molecule. It is synthesized endogenously and can be taken as an oral supplement. This review aimed to identify the effects of oral ATP supplementation on anaerobic exercise in healthy resistance-trained adults. A systematic review and meta-analysis were performed based on the Preferred Reporting Items of Systematic Reviews and Meta-Analysis (PRISMA) criteria. The inclusion criteria were articles published from 2000 to 2022, with anaerobic variables (maximal strength, maximum repetitions, and maximum anaerobic power) measurable in healthy adults with experience in resistance training, only randomized placebo-controlled clinical trials (RCTs), and with the acute (a single dose 30 min to 24 h before the tests) and/or chronic (>1 day) oral supplementation of ATP. A total of five RCTs with 121 adult men were included. The oral ATP supplementation achieved significantly greater gains in maximal strength compared with the placebo (PL) (MD = 8.13 kg, 95%CI [3.36-12.90], p < 0.001). Still, no differences were observed in the maximum number of repetitions or the maximum anaerobic power. Furthermore, 400 mg of ATP showed improvement in anaerobic exercise regardless of the duration of the supplementation protocol. In conclusion, supplementation with 400 mg of ATP doses can improve maximal muscle strength in resistance-trained men.

A new sports garment with elastomeric technology optimizes physiological, mechanical, and psychological acute responses to pushing upper-limb resistance exercises.

This study aimed to compare the mechanical (lifting velocity and maximum number of repetitions), physiological (muscular activation, lactate, heart rate, and blood pressure), and psychological (rating of perceived exertion) responses to upper-body pushing exercises performed wearing a sports elastomeric garment or a placebo garment. Nineteen physically active young adults randomly completed two training sessions that differed only in the sports garment used (elastomeric technology or placebo). In each session, subjects performed one set of seated shoulder presses and another set of push-ups until muscular failure. The dependent variables were measured immediately after finishing the set of each exercise. Compared to the placebo garment, the elastomeric garment allowed participants to obtain greater muscular activation in the pectoralis major (push-ups: p = 0.04, d = 0.49; seated shoulder press: p < 0.01, d = 0.64), triceps brachialis (push-ups, p < 0.01, d = 0.77; seated shoulder press: p < 0.01, d = 0.65), and anterior deltoid (push-ups: p < 0.01, d = 0.72; seated shoulder press: p < 0.01, d = 0.83) muscles. Similarly, participants performed more repetitions (push-ups: p < 0.01; d = 0.94; seated shoulder press: p = 0.03, d = 0.23), with higher movement velocity (all p ≤ 0.04, all d ≥ 0.47), and lower perceived exertion in the first repetition (push-ups: p < 0.01, d = 0.61; seated shoulder press: p = 0.05; d = 0.76) wearing the elastomeric garment compared to placebo. There were no between-garment differences in most cardiovascular variables (all p ≥ 0.10). Higher diastolic blood pressure was only found after the seated shoulder press wearing the elastomeric garment compared to the placebo (p = 0.04; d = 0.49). Finally, significantly lower blood lactate levels were achieved in the push-ups performed wearing the elastomeric garment (p < 0.01; d = 0.91), but no significant differences were observed in the seated shoulder press (p = 0.08). Overall, the findings of this study suggest that elastomeric technology integrated into a sports garment provides an ergogenic effect on mechanical, physiological, and psychological variables during the execution of pushing upper-limb resistance exercises.

Mental fatigue impairs the number of repetitions to muscular failure in the half back‐squat exercise for low‐ and mid‐ but not high‐intensity resistance exercise

AbstractThe study aimed to analyze the acute effect of mental fatigue on the maximum number of repetitions in a resistance exercise session with different intensities in resistance‐trained adults. Eighteen young men aged between 18 and 25 years old (age, 22.1 ± 2.0 years; body weight, 82.5 ± 6.6 kg; height, 177.4 ± 5.2 cm; half‐back squat 1‐RM, 106.7 ± 21.9 kg) were recruited for the study. Each participant performed two trials (i.e., control and mental fatigue) in a random and balanced order for 30‐min. The participants performed three sets of half back‐squat exercise to failure, with intensities of 50%, 70%, and 90% of 1RM with a passive recovery interval of 5‐min between sets. The intensity was randomized and counterbalanced, and the order was maintained in both conditions for the same subject. We assessed resistance training using the number of repetitions to failure and perceived effort and checked the mental fatigue subjectively and objectively. The participants in the mental fatigue condition presented a significantly increased perception of mental fatigue (p &lt; 0.05) and reduced pupil diameter (p &lt; 0.05). The number of repetitions were significantly lower for the 50 (p &lt; 0.05) and 75% 1RM (p &lt; 0.05) in the mental fatigue condition, but the 90% 1RM remained similar (p &gt; 0.05). Also, the perceived effort showed significantly higher results for the 50 (p &lt; 0.05) and 75% 1RM (p &lt; 0.05) in the mental fatigue condition, but the 90% 1RM remained similar (p &gt; 0.05). Then, this study showed that mental fatigue reduced resistance exercise performance for low‐ and mid‐intensity but not for high‐intensity.

Fasting reduces satiety and increases hunger but does not affect the performance in resistance training.

Intermittent fasting (IF) has been suggested to reduce body fat percentage and improve non-communicable chronic diseases. However, little is known about resistance training (RT) and the subjective perception of hunger under fasted conditions. This study aimed to examine the effects of overnight fasting (12 h or 16 h fasting) on the maximum voluntary isometric contraction (MVIC) and countermovement jump (CMJ) performance in resistance-trained young male adults. In RT sessions, the maximum number of repetitions (MNR) and the total volume load (TVL) were evaluated in the back squat and leg press 45°. The volunteers performed all tests and the RT session in 3 different conditions: fed state, 12 and 16 hours of IF. The subjective perception of hunger was applied through an adapted visual analogue scale (adVAS). The results showed that strength and power variables did not change significantly: MVIC (p = 0.960), CMJ (p = 0.986), MNR back squat (p = 0.856), MNR leg press 45° (p = 0.998), TVL (p = 0.954). However, hunger was significantly greater after the 16-hour fasting (p = 0.001) compared to 12 hours of fasting and the fed state. Also, the desire to eat was greater after 16 hours (p = 0.001) compared to 12 hours of fasting and the fed state. This study indicates that IF for 12 or 16 hours does not significantly impair strength and power, but the longer the fasting duration, the greater are the hunger and desire to eat.

Effects of muscular endurance and tendon extensibility on endurance of joint stiffness

ABSTRACT In some sporting events (e.g., long-distance running), the ability to maintain joint stiffness is considered an essential physical ability. However, the determinants of joint stiffness endurance remain unclear. This study aimed to examine the effects of muscular endurance and tendon extensibility on joint stiffness endurance. Thirteen males performed the fatigue task (5 sets of 50 hopping). Ankle joint stiffness during drop jump was measured before and after fatigue task. The maximum number of repetitions at 30% of one repetition maximum for plantar flexion was measured as muscular endurance. Maximal elongation of the Achilles tendon was measured during ramp (with a low strain rate of tendon) and ballistic (with a high strain rate of tendon) contractions as tendon extensibility. Joint stiffness significantly decreased by 7.5% after the fatigue task (p = 0.033). The maximum number of repetitions at 30% of 1RM (79.6 ± 48.7 repetitions) was not significantly correlated with the relative change in joint stiffness (r = 0.283, p = 0.348). The maximal elongation of the Achilles tendon measured during ramp and ballistic contractions were not significantly associated with the relative change in joint stiffness (r = 0.326, p = 0.277 for ramp contraction; r = 0.438, p = 0.135 for ballistic contraction). These results suggest that muscular endurance and tendon extensibility were unrelated to joint stiffness endurance.

Prediction of Scrabble game players based on ARIMA and Machine Learning under big data

Wordle is a favored puzzle. Firstly, to predict its daily player count, based on analyzing the inherent trend of the data and verifying its stationarity, the effectiveness of using the ????????????????????((2,3,5),2,(2,3,5)) model to predict the number of reported results is proved. Before predicting, this thesis preprocesses the data from two parts: Number of reported results and Number in hard mode. Then, the 95% prediction interval for March 1, 2023, is [8626 16199]. Secondly, to predict the distribution of reported results percentages, this thesis uses 7 random forest regressors, their feature variables have 5 dimensions (Contest number, Frequency of word, Number of repeated types, Number of letter types, Maximum number of repetitions), and the response variable takes one of the percentages (7 dimensions) in turn. Results show that the distribution of reported results percentages of “SALSA” on March 1,2023 is [0, 2, 15, 35, 31, 15, 2].

Development of maximum strength, resistance and body composition

The present study aimed to verify the effects of the use of anabolic androgenic steroids (AAS) in the development of maximum strength, resistance strength and body composition in resistance training practitioners. This research is characterized as applied, with a descriptive field study with a quantitative approach. The intentional non-probabilistic sample was composed of 20 male individuals, experienced in strength training. Participants were allocated into two groups: GU (group of EAA users), and GNU (non-EAS users group). The subjects were submitted to an evaluation of body composition, maximum strength test (1RM) and maximum repetitions test (80%RM). The results found indicate that the use of EAA increases the production of maximum strength and relative strength, causing a moderate increase in fat-free mass. The improvement in performance by its use is not found in the number of maximum repetitions at 80% RM, as well as it does not seem to influence fat mass and body fat percentile.

The effects of ischemia during rest intervals on strength endurance performance.

The study aimed to evaluate the effects of ischemia used during the rest periods between successive sets on maximal number of performed repetitions, time under tension and bar velocity during the bench press exercise. Thirteen healthy resistance trained men volunteered for the study (age = 28.5 ± 7.1 years; body mass = 87.2 ± 8.6 kg; bench press 1RM = 143.1 ± 20.7 kg; training experience = 11.0 ± 6.9 years). In experimental protocol the subjects performed 5 sets of bench press exercise at 70%1RM with maximal number of repetitions in each and with 5 minutes rest periods between each set. During the ischemia condition occlusion with 80% arterial occlusion pressure (AOP) was applied using a 10 cm wide cuff, before the first set of the bench press exercise and during all rest periods between sets (for 4.5 minute). During the control condition no ischemia was applied. The two-way repeated measures ANOVA showed a statistically significant interaction effect for time under tension (p = 0.022; η2 = 0.20). However, the results did not show a statistically significant interaction effect for peak bar velocity (p = 0.28; η2 = 0.10) mean bar velocity (p = 0.38; η2 = 0.08), and for number of performed repetitions (p = 0.28; η2 = 0.09). The post hoc analysis for interaction showed significantly shorter time under tension for ischemia condition compared to control in set 1 (p < 0.01). The post hoc analysis for main effect of condition revealed that time under tension was significantly shorter for ischemia compared to control condition (p = 0.04). The results of this study indicate that ischemia intra-conditioning does not increase strength-endurance performance as well as bar velocity during bench press exercise performed to muscle failure.

Effects of Creatine Supplementation after 20 Minutes of Recovery in a Bench Press Exercise Protocol in Moderately Physically Trained Men.

The aims of this study were to analyse the effect of creatine supplementation on the performance improvement in a bench pressing (BP) strength test of muscle failure and to evaluate muscle fatigue and metabolic stress 20 min after the exercise. Fifty young and healthy individuals were randomly assigned to a creatine group (n = 25) or a placebo group (n = 25). Three exercise sessions were carried out, with one week of rest between them. In the first week, a progressive load BP test was performed until the individuals reached the one repetition maximum (1RM) in order to for us obtain the load-to-velocity ratio of each participant. In the second week, the participants conducted a three-set BP exercise protocol against 70% 1RM, where they performed the maximum number of repetitions (MNR) until muscle failure occurred, with two minutes of rest between the sets. After one week, and following a supplementation period of 7 days, where half of the participants consumed 0.3 g·kg-1·day-1 of creatine monohydrate (CR) and the other half consumed 0.3 g·kg-1·day-1 of placebo (PLA, maltodextrin), the protocol from the second week was repeated. After each set, and up to 20 min after finishing the exercise, the blood lactate concentrations and mean propulsive velocity (MPV) at 1 m·s-1 were measured. The CR group performed a significantly higher number of repetitions in Set 1 (CR = 14.8 repetitions, PLA = 13.6 repetitions, p = 0.006) and Set 2 (CR = 8 repetitions, PLA = 6.7 repetitions, p = 0.006) after supplementation, whereas no significant differences were seen in Set 3 (CR = 5.3 repetitions, PLA = 4.7 repetitions, p = 0.176). However, there was a significant increase in blood lactate at minute 10 (p = 0.003), minute 15 (p = 0.020), and minute 20 (p = 0.015) after the exercise in the post-supplementation period. Similarly, a significant increase was observed in the MPV at 1 m·s-1 in the CR group with respect to the PLA group at 10, 15, and 20 min after the exercise. Although the creatine supplementation improved the performance in the strength test of muscle failure, the metabolic stress and muscle fatigue values were greater during the 20 min of recovery.

Pre-workout supplementation of capsaicin does not increase resistance training performance in a multiexercise protocol in trained men

Purpose.The aim of this study was to investigate the acute effect of capsaicin supplementation on performance, perceived exertion, and perceived effects in a resistance training protocol for the lower body.Methods.The sample was 14 young men (22.21 ± 2.55 years; 82.35 ± 5.16 kg; 174 ± 0.7 cm; 9.08 ± 2.73% of body fat), with 4.19 ± 2.98 years of experience in resistance training. The study design was randomised, double-blind and crossover. The subjects performed the training protocol after consuming Capsaicin (12 mg) (CAP) or a placebo (PLA). The training protocol was: five sets of Back Squats and Leg Presses 45°, with 70% of 1RM until failure. The interval between sets was 90 seconds and 120 seconds between exercises. The number of maximum repetitions (NMR) and the rate of perceived exertion (RPE) were recorded after each set.Results.The paired t-test showed that there was no statistically significant difference between PLA and CAP in the mean NMR (&lt;i&gt;p&lt;/i&gt; = 0.251; 95%CI = –5.47 – 19.18), mean session volume load (VL) (weight lifted × NMR) (&lt;i&gt;p&lt;/i&gt; = 0.117; 95%CI = –582.70 – 4639.99) and in the mean RPE (&lt;i&gt;p&lt;/i&gt; = 0.458; 95%CI = –0.81 – 0.39).Conclusions.The acute capsaicin supplementation did not change the perception of vigour and side effects. Therefore, pre-workout capsaicin supplementation did not alter performance, RPE, or perceived effects in a lower body multi-exercise training protocol in trained men.

Effect of Movement Range in Maximum Number of Repetitions in Weight Training Exercises

Effect of Movement Range in Maximum Number of Repetitions in Weight Training Exercises

Neuromuscular Fatigue and Metabolic Stress during the 15 Minutes of Rest after Carrying Out a Bench Press Exercise Protocol.

Simple SummaryVelocity loss can help to determine neuromuscular fatigue after carrying out an exercise protocol with a load that is initially moved at a mean propulsive velocity of 1 m·s−1. Few studies have measured the time required to recover the pre-exercise velocity values after performing an exercise, with the aim of knowing the optimal recovery times. Therefore, the aim of this study was to analyse muscular fatigue and metabolic stress during the 15 min that follow the execution of a bench press exercise protocol. The results show that mean propulsive velocity was recovered from minute 10 of rest; however, the blood lactate levels were still high (>5 mmol·L−1). Therefore, although the capacity to apply a maximum mean propulsive velocity peak was recovered, the same could not be said for the capacity to maintain those strength levels to reproduce another exercise protocol involving the same muscle groups. Moreover, analysing the velocities and metabolic stress before and after the exercise protocol by different strength level groups, similar results were obtained.Background: Velocity loss (VL) at 1 m·s−1 can help to determine neuromuscular fatigue after performing an exercise protocol. The aim of this study was to analyse muscle fatigue and metabolic stress during the 15 min that follow the execution of a bench press (BP) exercise protocol. Methods: Forty-four healthy male students of sports science performed two exercise sessions separated by one week of rest. In the first week, the participants carried out a test with progressive loads in the (BP) exercise until reaching the one-repetition maximum (1RM) in order to obtain the load–velocity relationship of each participant. In the second week, each participant conducted three BP exercise sets at an intensity of 70% of 1RM, determining this load through the mean propulsive velocity (MPV) obtained from the individual load–velocity relationship, with the participants performing the maximum number of repetitions (MNR) to muscle failure. Two minutes of rest were allocated between sets. MPV at 1 m·s−1 and blood lactate concentrations were recorded before executing the exercise and at minute 0, 5, 10 and 15 after performing the exercise protocol. Results: A two-factor repeated measures ANOVA was performed. MPV at 1 m·s−1 in minute 0 post-exercise was −33.3% (p < 0.05), whereas in minute 10 and 15 post-exercise, it was ≈−9% (p > 0.05). Regarding the blood lactate levels, significant differences were observed in all measurements before and after the exercise protocol (p < 0.001), obtaining ≈7 mmol·L−1 at minute 10 post-exercise and 4.3 mmol·L−1 after 15 min of recovery. Conclusions: MPV with medium or moderate loads shows a certain recovery from minute 10 of rest. However, the blood lactate levels are still high (>5 mmol·L−1). Therefore, although there seem to be certain conditions to reach a similar maximum MPV peak, the residual fatigue at the neuromuscular level and the non-recovery of metabolic homeostasis would hinder the reproduction of these protocols, both at the level of applied stimulus and from a methodological perspective, since a long recovery time would be required between sets and exercises.

Analysis of the Physiognomy of Unique Sets in the Maximum Number of Repetitions Strategy—The Case of One-Arm Scott Machine Seated Bicep Curls

The aim of this paper is to analyze the physiognomy of unique sets in the maximum number of repetitions (MNR) strategy and different correlations between the maximal forces, duration and volume for a relevant exercise in the case of a small muscle group. The research methodology proposes testing, in two phases, a total of 30 male students, for bicep curl exercises carried out on a bicep Scott machine. The obtained results showed that there were significant differences between the maximum forces (Fmax) developed during the initial and final repetitions of the exercise sets or for different machine loads. There was a large correlation between the load and Fmax and an inverse correlation between the load and MNR or between the MNR and Fmax. The deterioration of the execution mode, represented by the profile of the final repetition of high-duration sets, was also tested and analyzed. We concluded that the study of the physiognomy of cycles and comparisons at the level of relevant repetitions have revealed new perspectives for the design of periodization strategies, for the possibility of manipulating adapted muscular response or compensatory acceleration training for small muscle groups or the MNR strategy.

Impact of Interrepetition Rest on Muscle Blood Flow and Exercise Tolerance during Resistance Exercise.

Background and Objectives: Muscle blood flow is impeded during resistance exercise contractions, but immediately increases during recovery. The purpose of this study was to determine the impact of brief bouts of rest (2 s) between repetitions of resistance exercise on muscle blood flow and exercise tolerance. Materials and Methods: Ten healthy young adults performed single-leg knee extension resistance exercises with no rest between repetitions (i.e., continuous) and with 2 s of rest between each repetition (i.e., intermittent). Exercise tolerance was measured as the maximal power that could be sustained for 3 min (PSUS) and as the maximum number of repetitions (Reps80%) that could be performed at 80% one-repetition maximum (1RM). The leg blood flow, muscle oxygenation of the vastus lateralis and mean arterial pressure (MAP) were measured during various exercise trials. Alpha was set to p ≤ 0.05. Results: Leg blood flow was significantly greater, while vascular resistance and MAP were significantly less during intermittent compared with continuous resistance exercise at the same power outputs (p < 0.01). PSUS was significantly greater during intermittent than continuous resistance exercise (29.5 ± 2.1 vs. 21.7 ± 1.2 W, p = 0.01). Reps80% was also significantly greater during intermittent compared with continuous resistance exercise (26.5 ± 5.3 vs. 16.8 ± 2.1 repetitions, respectively; p = 0.02), potentially due to increased leg blood flow and muscle oxygen saturation during intermittent resistance exercise (p < 0.05). Conclusions: In conclusion, a brief rest between repetitions of resistance exercise effectively decreased vascular resistance, increased blood flow to the exercising muscle, and increased exercise tolerance to resistance exercise.

Reproducibility and Applicability of Traditional Strength Training Prescription Recommendations.

Simple SummaryOne of the main problems that exercise professionals face is controlling and quantifying the real load of resistance training in an objective manner. Several authors have made recommendations aimed at improving strength for different populations. However, it is necessary to verify whether these recommendations can be implemented, completing them in their entirety. Therefore, the aim of this study was to verify the reproducibility of a resistance training protocol in the bench press exercise, based on traditional recommendations, analysing the effect of the muscle fatigue of each set and of the whole exercise protocol. Thirty participants performed a bench press exercise protocol of three sets with the maximum number of repetitions possible to muscle failure (with 2 min rests between sets), using a relative load corresponding to 70% 1RM determined through the mean propulsive velocity obtained from the individual load–velocity relationship. The conclusions of the study were that it was not possible to complete the same number of repetitions in each set for the same absolute load. Moreover, the level of fatigue generated through each set and its relationship with the capacity to recover in the established time could be different in each individual, showing an important coefficient of variation in each of the sets.Background: The aim of this study was to verify the reproducibility of a resistance training protocol in the bench press (BP) exercise, based on traditional recommendations, analysing the effect of the muscle fatigue of each set and of the whole exercise protocol. Methods: In this cross-sectional study, thirty male physical education students were divided into three groups according to their relative strength ratio (RSR), and they performed a 1RM BP test (T1). In the second session (T2), which was one week after T1, the participants performed a BP exercise protocol of three sets with the maximum number of repetitions (MNR) possible to muscle failure, using a relative load corresponding to 70% 1RM determined through the mean propulsive velocity (MPV) obtained from the individual load–velocity relationship, with 2 min rests between sets. Two weeks later, a third session (T3) identical to the second session (T2) was performed. The MPV of each repetition of each set and the blood lactate level after each set were calculated, and mechanical fatigue was quantified through the velocity loss percentage of the set (% loss MPV) and in a pre-post exercise test with an individual load that could be lifted at ~1 m·s−1 of MPV. Results: The number of repetitions performed in each set was significantly different (MNR for the total group of participants: set 1 = 12.50 ± 2.19 repetitions, set 2 = 6.06 ± 1.98 repetitions and set 3 = 4.20 ± 1.99 repetitions), showing high variation coefficients in each of the sets and between groups according to RSR. There were significant differences also in MPVrep Best (set 1 = 0.62 ± 0.10 m·s−1, set 2 = 0.42 ± 0.07 m·s−1, set 3 = 0.36 ± 0.10 m·s−1), which significantly reduced the % loss MPV of all sets (set 1 = 77.4%, set 2 = 64%, set 3 = 54.2%). The lactate levels increased significantly (p < 0.05) (set 1 = 4.9 mmo·L−1, set 2 = 6 mmo·L−1, set 3 = 6.5 mmo·L−1), and MPV loss at 1 m·s−1 after performing the three sets was 36% in T2 and 34% in T3, with acceptable intrasubject variability (MPV at 1 m·s−1 pre-exercise: SEM ≤ 0.09 m·s−1, CV = 9.8%; MPV at 1 m·s−1 post-exercise: SEM ≤ 0.07 m·s−1, CV = 11.7%). Conclusions: These exercise propositions are difficult to reproduce and apply. Moreover, the number of repetitions performed in each set was significantly different, which makes it difficult to define and control the intensity of the exercise. Lastly, the fatigue generated in each set could have an individual response depending on the capacity of each subject to recover from the preceding maximum effort.

Improved conductivity and flatness of solution-processed transparent multilayer ZnO conductive films by stacking method

ZnO stacked films are prepared by a wet process under various conditions. Al and Ga are co-doped as dopants, i.e., producing AGZO films. The doping density dependence of the film resistivity shows that the best doping condition is 1.0 wt% of Ga-doping density and 0.1 wt% of Al-doping density, where the minimum sheet resistance of 1.2 × 105 Ω/□ and the best orientation of (002) surface are observed. The stacked AGZO films are prepared by two different methods to improve film properties: Method A is repeated provisional annealing, spin coating, and main annealing, where the maximum number of repetitions is three. On the other hand, method B is repeated provisional annealing and spin coating followed by annealing the stacked films only one time. As a result, the AGZO films produced by method B reveal a minimum surface roughness of about 3.2 nm. In addition, with an increase of the stacked layers, the sheet resistance is decreased.

Blood Pressure and Blood Glucose Responses to Combined Exercise Sessions of Different Intensities in Individuals with Cardiovascular Risk Factors

ABSTRACT Objective The purpose of the present study was to verify the acute effects of blood pressure and blood glucose after two sessions of combined exercise sessions performed at two levels of intensity in trained individuals with cardiovascular risk factors. Methods Eighteen individuals (66.22 ± 8.61 years) of both sexes (6 women/12 men) with cardiovascular risk factors performed two sessions of combined exercises at different levels of intensity: moderate (MOD) and high (HI). To control the intensity of the aerobic training, the Borg Rating of Perceived Exertion (RPE) Scale was used. For the strength training, the maximum number of repetitions was carried out within a predetermined duration of sets. Blood pressure and blood glucose measurements were collected before and 20 minutes after the sessions. The data were analyzed using Generalized Estimating Equations, α 5%. Results Reductions were observed in systolic blood pressure (MOD – Δ = −4.95 mmHg; HI – Δ = −3.31 mmHg) and blood glucose (MOD – Δ = −16.06 mg/dL; HI – Δ = −29.45 mg/dL) after the two sessions, with no difference between sessions. Diastolic blood pressure did not change (p < .05). Conclusion Combined exercises sessions of moderate or high intensity can promote an acute reduction in systolic blood pressure and glycemia in individuals with cardiovascular risk factors.

Analysis of the Use and Applicability of Different Variables for the Prescription of Relative Intensity in Bench Press Exercise.

Simple SummaryThe aim of this research is to analyze the different variables that influence the prescription of resistance training (one-repetition maximum (1RM) and number of maximal repetitions (xRM)) through the velocity of execution, with the aim of approaching the precise definition and control of intensity in bench press exercise. Fifty male physical education students were divided into four groups according to their relative strength ratio (RSR) and performed a 1RM bench press test, and two maximum number of repetitions (MNR) tests one week apart, using a relative load corresponding to 70% 1RM determined through the mean propulsive velocity (MPV) obtained from the individual load–velocity relationship. Regarding MPV, the best (fastest) repetition of the set values were similar between groups (0.62 m·s−1–0.64 m·s−1). The average MNR was 12.38 ± 2.51, with significant variation between groups with regards to MNR (CV:13–29%), and greater variability in the group corresponding to the lowest RSR values (CV: 29%). The use of variables such as the 1RM or a MNR do not allow an adequate degree of precision to prescribe and control the relative intensity of resistance training. Besides, execution velocity control can offer an adequate alternative to guarantee an accurate prescription of intensity with regard to resistance training.Background: The aim of the study was to analyze the use of variables such as % of one-repetition maximum (1RM) and number of maximal repetitions (xRM) with execution velocity to define and control the intensity of resistance training in bench press exercise. Hence, exercise professionals will achieve better control of training through a greater understanding of its variables. Methods: In this cross-sectional study, fifty male physical education students were divided into four groups according to their relative strength ratio (RSR) and performed a 1RM bench press test (T1). In the second test, participants performed repetitions to exhaustion (T2), using a relative load corresponding to 70% 1RM determined through the mean propulsive velocity (MPV) obtained from the individual load–velocity relationship. This same test was repeated a week later (T3). Tests were monitored according to the MPV of each repetition and blood lactate values (LACT). Results: Regarding MPV, the best (fastest) repetition of the set (MPVrep Best) values were similar between groups (0.62 m·s−1–0.64 m·s−1), with significant differences in relation to the high RSR group (p < 0.001). The average maximum number of repetitions (MNR) was 12.38 ± 2.51, with no significant differences between the RSR groups. Nonetheless, significant variation existed between groups with regards to MNR (CV: 13–29%), with greater variability in the group corresponding to the lowest RSR values (CV: 29%). The loss of velocity in the MNR test in the different groups was similar (p > 0.05). Average LACT values (5.72 mmol·L−1) showed significant differences between the Medium RSR and Very Low RSR groups. No significant differences were found (p > 0.05) between T2 and T3 with regards to MNR, MPVrep Best, or MPVrep Last, with little variability seen between participants. Conclusions: The use of variables such as the 1RM, estimated using an absolute load value, or an MNR do not allow an adequate degree of precision to prescribe and control the relative intensity of resistance training. Besides, execution velocity control can offer an adequate alternative to guarantee an accurate prescription of intensity with regard to resistance training.