Untrained Adults Research Articles

The effects of sport-specific training on individuals action strategies while avoiding a virtual player approaching on a 45° angle while completing a secondary task.

Sports provide varying scenarios where athletes must interact with and avoid opposing players in dynamic environments. As such, sport-specific training can improve one's ability to integrate visual information which may result in improved collision avoidance behaviours. However, improved visuomotor capabilities are highly task dependent (i.e., athletes must be tested in sport-specific settings). The current study examined whether sport-specific training influenced individuals' collision avoidance behaviours during a sport-specific task in virtual reality. Untrained young adults (N = 21, 22.9±1.9 yrs, 11 males) and specifically trained athletes (N = 18, 20±1.5 yrs, 7 males) were immersed in a virtual environment and were instructed to walk along a 7.5m path towards a goal located along the midline. Two virtual players positioned 2.83m to the left and right of the midline approached participants on a 45° angle at one of three speeds: 0.8x, 1.0x, or 1.2x each participant's average walking speed. Participants were instructed to walk to a goal without colliding with the virtual players while performing a secondary task; reporting whether a shape changed above either of the virtual players' heads. Results revealed that athletes had a higher percentage of correct responses on the secondary task compared to untrained young adults. However, there was no group differences in the average time to first avoidance or average minimum clearance, but athletes were more variable in their avoidance behaviours. Findings from this study demonstrate that athletes may be more adaptive in their behaviours and may perform better on attentionally demanding tasks in dynamic environments.

Effect Of Acute Exercise Intensity On Ghrelin Levels In Untrained Adults

Effect Of Acute Exercise Intensity On Ghrelin Levels In Untrained Adults

2-week Microcycles Of Aerobic And Resistance Exercise Elicit Different Health Improvements In Untrained Healthy Adults

2-week Microcycles Of Aerobic And Resistance Exercise Elicit Different Health Improvements In Untrained Healthy Adults

High Cognitive Effort Prior to Velocity-Based Training Sessions Reduces Rate of Force Development but Not Maximum Strength Gains in Untrained Male Adults.

This study aimed to analyze the chronic effect of high cognitive effort immediately before resistance exercise sessions on neuromuscular performance in untrained male adults. We used a mixed experimental design, with the group as between-participants factor and time as within-participants factor. Thirty-four participants were randomly assigned to two parallel groups: high cognitive effort (n = 17) and control (n = 17). Subjects in the control group were seated for 30 min before the resistance exercise sessions, while the high cognitive effort group completed incongruent trials of the Stroop task until subjective mental fatigue was present immediately before resistance exercise sessions. Participants attended 45 sessions over 15 weeks, consisting of three familiarizations, three baseline evaluations, 36 velocity-based training sessions, and three postexperiment evaluation sessions. Rate of force development (RFD) during the isometric mid-thigh pull, half back-squat 1-RM, and countermovement jump (CMJ) were measured before and after the 12-week intervention. A significant group × time interaction effect was found for the average RFD at 0-250 ms (p < 0.05), with greater improvements for the control group than for the high cognitive effort group. There was no group × time interaction for half back-squat 1-RM (p > 0.05). Also, there was no group × time interaction for CMJ (p > 0.05). In conclusion, repeated high cognitive effort immediately prior to resistance exercise sessions is a phenomenon that can induce greater early velocity loss and, consequently, impairs the improvements in RFD. However, this did not inhibit the increased performance for explosive strength and CMJ in male untrained adults. High cognitive effort before resistance exercise sessions should be avoided.

Recreational beach tennis training reduces ambulatory blood pressure in adults with hypertension: a randomized clinical trial.

To determine the effect of 12 weeks of beach tennis training on 24-h ambulatory blood pressure in adults with essential hypertension. This was a randomized, single-blinded, two-arm, parallel superiority trial. Forty-two participants aged 35-65 years with a previous diagnosis of hypertension were randomized into 12 weeks of beach tennis training group (two sessions per week lasting 45-60 min) or a nonexercising control group. Ambulatory 24 h (primary outcome) and office blood pressure, heart rate at rest, cardiorespiratory fitness, and muscle strength were assessed at baseline and after the intervention period. Generalized estimating equation analyses were employed to examine the main effects of the interventions. In the beach tennis group, night-time systolic (-9 mmHg, P = 0.023), diastolic (-4 mmHg, P = 0.026), and mean arterial pressure (-7 mmHg, P = 0.023) decreased after 12 weeks of training. The office SBP/DBP (-6 mmHg, P = 0.016/-6 mmHg, P = 0.001) also decreased in the beach tennis group. Heart rate at rest decreased in the beach tennis group (-4 bpm, P = 0.012) but increased in the control group (6 bpm, P = 0.005). The lower and upper limb muscle strength increased in the beach tennis group after training. However, no such changes were observed in the control group. A 12-week recreational beach tennis training significantly reduced office and ambulatory BP among untrained adults with essential hypertension. Additionally, participation in this sport has led to improvements in physical fitness and overall cardiovascular risk profiles.This clinical trial was registered at Clinicaltrials.gov (NCT03909321).

Protein Supplementation Increases Adaptations to Low-Volume, Intra-Session Concurrent Training in Untrained Healthy Adults: A Double-Blind, Placebo-Controlled, Randomized Trial.

Combined endurance and resistance training, also known as "concurrent training", is a common practice in exercise routines. While concurrent training offers the benefit of targeting both cardiovascular and muscular fitness, it imposes greater physiological demands on the body compared to performing each modality in isolation. Increased protein consumption has been suggested to support adaptations to concurrent training. However, the impact of protein supplementation on responses to low-volume concurrent training is still unclear. Forty-four untrained, healthy individuals (27 ± 6 years) performed two sessions/week of low-volume high-intensity interval training on cycle ergometers followed by five machine-based resistance training exercises for 8 weeks. Volunteers randomly received (double-blinded) 40 g of whey-based protein (PRO group) or an isocaloric placebo (maltodextrin, PLA group) after each session. Maximal oxygen consumption (VO2max) and overall fitness scores (computed from volunteers' VO2max and one-repetition maximum scores, 1-RM) significantly increased in both groups. The PRO group showed significantly improved 1-RM in all major muscle groups, while the PLA group only improved 1-RM in chest and upper back muscles. Improvements in 1-RM in leg muscles were significantly greater in the PRO group versus the PLA group. In conclusion, our results indicate that adaptations to low-volume concurrent training, particularly leg muscle strength, can be improved with targeted post-exercise protein supplementation in untrained healthy individuals.

Effects of Tempo-Controlled Resistance Training on Corticospinal Tract Plasticity in Healthy Controls: A Systematic Review.

After musculoskeletal injuries, there is often a loss of corticospinal control. Current tendon rehabilitation may not adequately address the corticospinal control of the muscle which may contribute to the recalcitrance of symptom recurrence. This review provides a summary of the current literature regarding the effectiveness of tempo-controlled resistance training (TCRT) in (1) promoting corticospinal plasticity, (2) improving physical performance, and (3) improving strength outcomes in healthy adults. A comprehensive literature search was conducted using electronic databases (PubMed, CINAHL, Embase, and Google Scholar) to identify relevant studies published between 2010 and 2023. Randomized control (RCT) studies that included recreationally trained and untrained healthy adults between 18 and 60 years of age and that compared a TCRT intervention to a control condition were included. Twelve of the 1255 studies identified in the initial search were included in the final analysis. Throughout all included studies, TCRT was shown to elicit greater neural adaptations compared to traditional resistance training methods (i.e., self-paced strength training). These results indicate that TCRT holds promise as an effective method for modulating corticospinal plasticity in healthy adults and may enhance neuromuscular adaptations, including improvements in CSE, decreased SICI, enhanced motor unit synchronization, and voluntary muscle activation.

Immersive Virtual Reality Decreases Work Rate and Manipulates Attentional Focus During Self-Regulated Vigorous Exercise

ABSTRACT To determine the effect of immersive virtual reality use on finishing time of a vigorous-intensity self-regulated exercise task, and on relevant psychological variables. Healthy untrained adults (N = 21; 10 men/11 women; age = 22.9 ± 7.2 years; BMI = 24.0 ± 4.5 kg/m2) completed 1500-m exercise bouts on a rowing ergometer in a counterbalanced and randomized order, with and without use of a headset-delivered virtual reality fitness program. Heart rate, rating of perceived exertion, affective valence, and attentional focus were collected every 300 m, in addition to finishing time. Data were analyzed with repeated measures as appropriate. Intensity of both exercise bouts was considered vigorous according to heart rate results (>77% maximal heart rate). Finishing time was faster in the control condition (449.57 ± 82.39 s) than in the virtual reality condition (463.00 ± 91.78 s), p = .007. Compared to the control condition, the virtual reality condition was characterized by a more external attentional focus (52.38 ± 18.22 vs. 38.76 ± 17.81, p < .001). No differences were observed for remaining variables as a result of condition (p > .05 for all). When a headset-delivered VR program was used during a self-regulated vigorous-intensity exercise task, participants were 13.6 seconds (~3%) slower than in a control condition. Attentional focus was manipulated to be more external with VR use, which may have ultimately distracted from the exercise objective. Recommendations for selecting an appropriate virtual reality experience for a given exercise task are discussed.

Influence of supervision ratio on functional physical performance and cellular health to collective multicomponent training in untrained adults aged

In pragmatic settings, involving elderly individuals in physical activity programs typically does not require individualized training. Thus, the aim of this study was to assess the impact on functional physical performance and cellular health resulting from a high (10 participants to 1 supervisor) versus low (20 participants to 1 supervisor) supervision ratio in a group-based multicomponent training program for older women. The experimental procedure presented three phases: a) pre-assessment (physical functional performance and cellular health); b) multicomponent training program (2 sessions/week); c) post-assessment. Performance variables were normalized with a t-score and the statistical analysis was based on the individual relative position in the t-score. After the collective multicomponent training intervention, 55 % of participants were above the mean t-score; however, low supervision ratio group (20:1) did not change functional physical performance and cellular health. A high supervision ratio is an important condition to improve individual older women response during a collective multicomponent training program.

Impact of low-load resistance exercise with and without blood flow restriction on muscle strength, endurance, and oxidative capacity: A pilot study.

Low-load resistance exercise (LLRE) to failure can increase muscle mass, strength, endurance, and mitochondrial oxidative capacity (OXPHOS). However, the impact of adding blood flow restriction to low-load resistance exercise (LLBFR) when matched for volume on these outcomes is incompletely understood. This pilot study examined the impact of 6 weeks of single-legged LLBFR and volume-matched LLRE on thigh bone-free lean mass, strength, endurance, and mitochondrial OXPHOS. Twenty (12 males and 8 females) untrained young adults (mean ± SD; 21 ± 2 years, 168 ± 11 cm, 68 ± 12 kg) completed 6 weeks of either single-legged LLBFR or volume-matched LLRE. Participants performed four sets of 30, 15, 15, and 15 repetitions at 25% 1-RM of leg press and knee extension with or without BFR three times per week. LLBFR increased knee extension 1-RM, knee extension endurance, and thigh bone-free lean mass relative to control (all p < 0.05). LLRE increased leg press and knee extension 1-RM relative to control (p = 0.012 and p = 0.054, respectively). LLRE also increased mitochondrial OXPHOS (p = 0.047 (nonparametric)). Our study showed that LLBFR increased muscle strength, muscle endurance, and thigh bone-free lean mass in the absence of improvements in mitochondrial OXPHOS. LLRE improved muscle strength and mitochondrial OXPHOS in the absence of improvements in thigh bone-free lean mass or muscle endurance.

Skeletal muscle myosin heavy chain protein fragmentation as a potential marker of protein degradation in response to resistance training and disuse atrophy.

We sought to examine how resistance exercise (RE), cycling exercise, and disuse atrophy affect myosin heavy chain (MyHC) protein fragmentation in humans. In the first study (1boutRE), younger adult men (n=8; 5±2 years of RE experience) performed a lower body RE bout with vastus lateralis (VL) biopsies obtained immediately before, 3-, and 6-hours post-exercise. In the second study (10weekRT), VL biopsies were obtained in untrained younger adults (n=36, 18 men and 18 women) before and 24 hours (24h) after their first/naïve RE bout. These participants also engaged in 10 weeks (24 sessions) of resistance training and donated VL biopsies before and 24h after their last RE bout. VL biopsies were also examined from a third acute cycling study (n=7) and a fourth study involving two weeks of leg immobilization (n=20, 15 men and 5 women) to determine how MyHC fragmentation was affected. In the 1boutRE study, the fragmentation of all MyHC isoforms (MyHCTotal) increased 3 hours post-RE (~ +200%, p=0.018) and returned to pre-exercise levels by 6 hours post-RE. Immunoprecipitation of MyHCTotal revealed ubiquitination levels remained unaffected at the 3- and 6-hour post-RE time points. Interestingly, a greater increase in magnitude for MyHC type IIa versus I isoform fragmentation occurred 3-hours post-RE (8.6±6.3-fold versus 2.1±0.7-fold, p=0.018). In all 10weekRT participants, the first/naïve and last RE bouts increased MyHCTotal fragmentation 24h post-RE (+65% and +36%, respectively; p<0.001); however, the last RE bout response was attenuated compared to the first bout (p=0.045). The first/naïve bout response was significantly elevated in females only (p<0.001), albeit females also demonstrated a last bout attenuation response (p=0.002). Although an acute cycling bout did not alter MyHCTotal fragmentation, ~8% VL atrophy with two weeks of leg immobilization led to robust MyHCTotal fragmentation (+108%, p<0.001), and no sex-based differences were observed. In summary, RE and disuse atrophy increase MyHC protein fragmentation. A dampened response with 10 weeks of resistance training, and more refined responses in well-trained men, suggest this is an adaptive process. Given the null polyubiquitination IP findings, more research is needed to determine how MyHC fragments are processed. Moreover, further research is needed to determine how aging and disease-associated muscle atrophy affect these outcomes, and whether MyHC fragmentation is a viable surrogate for muscle protein turnover rates.

Abdominal Fatigue Impairs Anaerobic, but not Aerobic,Cycling Performance in Untrained Adults

Relevance. Coaches and athletes across a variety of sports commonly perform abdominal exercises to promote core strength and endurance. However, the precise influence of abdominal strength and endurance on cycling performance remains elusive. Purpose. Determine whether abdominal fatigue affects anaerobic sprint and aerobic time- trial (TT) cycling performance. Methods. Twenty-three untrained young adults (age: 19,2 ± 1,0 years, height: 170,4 ± 7,5 cm, and weight: 74,5 ± 14,1 kg) participated in this study. Twelve of the participants completed two Wingate anaerobic power tests on a Monark 834 E ergometer set at 7,5 % of body mass and the remaining 11 participants completed two 3,2 km cycling TTs on an Expresso S3U virtual reality bike; tests were separated by 96 hours. All participants performed abdominal crunches to fatigue prior to the second test. Dependent t-tests were used to assess differences between the cycling trials for the two groups. Results. Abdominal muscle fatigue decreased mean anaerobic power (Pre: 486,75 vs. Post: 408,83 Watts (W, p &lt; 0,001), increased the rate of fatigue (Pre: 42,01 vs. Post: 50,32 %, p = 0,004), and tended to decrease peak anaerobic power (Pre: 643,17 vs. Post: 607,27 W, p = 0,088). However, abdominal muscle fatigue did not affect TT mean power (Pre: 228,18 vs. Post: 220,09 W, p = 0,127) or TT performance (Pre: 382,7 vs. Post: 388,0 seconds, p = 0,222). Conclusion. Abdominal fatigue negatively affects anaerobic cycling performance in untrained young adults. Future studies should evaluate the impact of abdominal fatigue on cycling performance in trained cyclists.

Comparison of the effects of core stability and whole-body electromyostimulation exercises on lumbar lordosis angle and dynamic balance of sedentary people with hyperlordosis: a randomized controlled trial

BackgroundHyperlordosis is an excessive inward curvature of the lumbar spine that affects spinal function. The aim of this study was to compare the effects of core stability exercises (CSE), Whole-Body Electromyostimulation (WB-EMS), and CSE Plus on the Lumbar lordosis angle and dynamic balance in sedentary people with hyperlordosis.MethodsIn a parallel randomized controlled trial study, seventy five untrained male adults with hyperlordosis, recruited from clinics of sports medicine and corrective exercise centers in Tehran, were randomly assigned to four groups: CSE (n = 19), WB-EMS (n = 18), CSE Plus (n = 18), and control Group (CG) (n = 20). The CSE group performed Core stability exercises, the WB-EMS group followed a Whole-body electromyostimulation combined training protocol, and the CSE Plus group engaged in a combined program protocol (CSE with the WB-EMS vest), and the control group only participated in activities of daily living. Anthropometric parameters and outcomes, including the lordosis angle and dynamic balance, were assessed before and after a six-week training program. A flexible ruler was used to measure the angle of lordosis, and the Y balance test was employed to evaluate the dynamic balance.ResultsThe results indicated that the lordosis angle improved in both the CSE and CSE Plus groups compared to the CG in the post-test (P = 0.017, P = 0.024). However, there were no significant differences observed between the other group pairs. Additionally, a significant difference in dynamic balance was found between the CSE Plus group and the CG in the post-test (P = 0.001), while no significant differences were observed between the other group pairs. Furthermore, within-group test results demonstrated that lumbar lordosis angle and dynamic balance variables significantly improved in the post-test compared to the pre-test stage (P < 0.05).ConclusionsThe two CSE and CSE Plus training protocols are effective as training methods for correcting certain parameters and physical deformities, including lumbar lordosis. Furthermore, the CSE Plus group demonstrated a positive impact on improving dynamic balance. Consequently, it is highly recommended that individuals with hyperlordosis can benefit from the exercises of the present study, especially CSE Plus exercises along with other rehabilitation exercises.Trial registrationThe trial was registered at Thai Clinical Trials Registry (TCTR20221004011, registration date: 04/10/2022).

Comparative Efficacy of Different Protein Supplements on Muscle Mass, Strength, and Physical Indices of Sarcopenia among Community-Dwelling, Hospitalized or Institutionalized Older Adults Undergoing Resistance Training: A Network Meta-Analysis of Randomized Controlled Trials.

Aging-related sarcopenia exerts harmful impacts on muscle mass, strength, and physical mobility. Protein supplementation has been demonstrated to augment efficacy of resistance training (RT) in elderly. This study compared the relative effects of different protein supplements on muscle mass, strength, and mobility outcomes in middle-aged and older individuals undergoing RT. A comprehensive search of online databases was performed to identify randomized controlled trials (RCTs) examining the efficacy of protein supplement plus RT in untrained community-dwelling adults, hospitalized, or institutionalized residents who suffered acute or chronic health conditions. Network meta-analysis (NMA) was performed using a frequentist method for all analyses. Treatment effects for main outcomes were expressed as standard mean difference (SMD) with 95% confidence interval (CI). We used the surface-under-the cumulative-ranking (SUCRA) scores to rank probabilities of effect estimation among all identified treatments. Meta-regression analyses were performed to identify any relevant moderator of the treatment efficacy and results were expressed as β with 95% credible interval (CrI). We finally included 78 RCTs (5272 participants) for analyses. Among the six protein sources identified in this NMA, namely whey, milk, casein, meat, soy, and peanut, whey supplement yielded the most effective treatments augmenting efficacy of RT on muscle mass (SMD = 1.29, 95% CI: 0.96, 1.62; SUCRA = 0.86), handgrip strength (SMD = 1.46, 95% CI: 0.92, 2.00; SUCRA = 0.85), and walking speed (SMD = 0.73, 95% CI: 0.39, 1.07; SUCRA = 0.84). Participant's health condition, sex, and supplementation dose were significant factors moderating the treatment efficacy on muscle mass (β = 0.74; 95% CrI: 0.22, 1.25), handgrip strength (β = -1.72; 95% CrI: -2.68, -0.77), and leg strength (β = 0.76; 95% CrI: 0.06, 1.47), respectively. Our findings suggest whey protein yields the optimal supplements to counter sarcopenia in older individuals undergoing RT.

Comparison of low-dose maximal-intent versus controlled-tempo resistance training on quality-of-life, functional capacity, and strength in untrained healthy adults: a comparative effectiveness study

Lack of physical activity is a global issue for adults that can lead to sedentary behaviour and a higher prevalence of health complications and chronic diseases, resulting in reduced quality-of-life (QoL) and functional capacity (FC). A potential strategy to mitigate this inactivity is low-dose resistance training (RT); however, physiological, and psychological responses are limited in evidence. Twenty untrained participants aged 30–60 years old (mean ± SD age 42 ± 7 years, mass 77 ± 13 kg, stature 166 ± 8 cm; 18 females and two males) were recruited and randomly assigned to maximal velocity-intent (MI, n = 10) or controlled-tempo (CT, n = 10) RT according to CONsolidated Standards of Reporting Trials (CONSORT) guidelines. Participants attended one training session per week for 6 weeks, consisting of five sets of five repetitions at 60% of one-repetition maximum (1RM) leg press. The interventions differed only during the concentric phase, with MI group pushing with maximal intent, and CT group pushing in a time-controlled manner (3 s). Outcome measures assessed pre- and post-RT included body mass, body mass index (BMI), strength-to-mass ratio, bipedal balance, 6-minute walk test (6MWT), 30-second sit-to-stand (30s-STS), timed up and go (TUG), and leg press 1RM. Time effects were observed for all demographics and FC-related outcomes, such as identical reductions in mass and BMI (− 2%), improvements in strength-to-mass ratio (25%) leg press 1RM (22%), 6MWT (3%), and 30s-STS (14%), as well as a 9% improvement in both TUG-clockwise and anticlockwise. Results show low-dose once-weekly RT is effective in improving QoL, FC, and strength in untrained healthy adults, regardless of modality. Positive responses from participants suggest an increased likelihood of consistent participation for low-dose once-weekly RT over more intense modalities. Retrospective ClinicalTrials.gov ID (TRN): NCT06107855, 24/10/2023.

Effects of a portable, cable-based concentric-only resistance machine on muscular strength in untrained young adults

The purpose of this study was to investigate the effects of concentric-only resistance training in comparison to traditional concentric-eccentric resistance training on upper and lower body strength using a portable cable-based concentric-only resistance machine. Thirty-two participants (10 females, 22 males; mean age of 23.4 ± 2.0) with minimal resistance training experience exercised thrice weekly to complete a 12-week training program. Participants were blinded and randomly allocated 1:1 to an intervention group (n = 16, wherein the resistance training used the concentric-only machine (CRT)) or a control group (n = 16, wherein the resistance training was completed using traditional concentric-eccentric with a conventional cable-based machine (CON)). While both groups improved in 1-RM chest press and squat press performance, there was no significant difference between groups. These findings suggest that the use of a portable CRT machine may confer similar strength benefits in comparison to traditional concentric-eccentric training. It is possible that the lack of the eccentric component with the CRT machine enables for a higher training volume to be completed, which consequently results in strength benefits.

The influence of cardiorespiratory fitness level on the relationship between work rates at the aerobic threshold (AerT) and the point of maximal fat oxidation (Fatmax) in untrained adults.

In this study, we investigated the impact of cardiorespiratory fitness (CRF), quantified as peak oxygen consumption (VO2peak), on the relationship between work rates (WR) at the aerobic threshold (AerT) and the point of maximal fat oxidation rate (Fatmax). A total of 761 untrained adults aged 41-68 completed a one-minute incremental exercise test on a cycle ergometer, using breath-by-breath gas analysis to determine VO2peak, AerT, and Fatmax. AerT was determined using automatic and visual detection methods, and Fatmax was determined using indirect calorimetry. Participants were categorized into CRF-groups: low (<25th percentile), medium (≥25th percentile and <75th percentile), and high (≥75th percentile). Fatmax was found at 43 ± 7% WRpeak, 37% ± 6% WRpeak and 35% ± 7% WRpeak in the low, medium, and high CRF-groups, respectively. In contrast, AerT was located at significantly higher relative work rates: 51% ± 8% WRpeak, 47% ± 10% WRpeak, and 47% ± 11% WRpeak in the respective CRF-groups. There was a weak agreement between Fatmax and AerT [intraclass correlation coefficient (ICC) = .19, p < .001], and the ICC decreased from .35 to .12 to .13, while the mean bias ±95% limits of agreement increased from 8% ± 14% WRpeak to 8% ± 19% WRpeak to 12% ± 44% WRpeak from CRF-low to CRF-medium to CRF-high. The mean difference between Fatmax and AerT was significantly different among the CRF subgroups: 8% ± 7% WRpeak vs. 10% ± 10% WRpeak vs. 12% ± 11% WRpeak in low, medium, and high CRF-groups, respectively. Nonetheless, multiple regression analysis revealed only a weak positive correlation between the difference in relative work rates (% WRpeak) between Fatmax and AerT (dependent variable) and the predictor variables CRF and sex, both identified as significant (R = .19, p < .001). Our study confirms substantial differences in exercise intensities between Fatmax and AerT in untrained adults (10% ± 19% WRpeak, ranging from -14% to 53% WRpeak). Importantly, this difference remains relatively consistent across varying CRF levels, emphasizing the distinct nature of Fatmax and AerT, with CRF playing a limited role in influencing their relationship in our study's untrained adults.

Short-term resistance training combined with cheese supplementation can optimize body parameters and intestinal microbiota in healthy adults

Background/ObjectiveResistance training (RT) and protein supplementation have beneficial effects on the human body. However, it is unknown if RT's health-promoting benefits are enhanced by food-borne protein, such as cheese supplements. This study investigated at how the body composition, lipid profile, muscle strength and intestinal microbiota changed following four weeks of RT combined with cheese supplementation. MethodsThirty-five male and untrained adults were divided into 4 groups [control group (CON), low-dose group (LG), medium-dose group (MG), and high-dose group (HG)] and underwent a 4-week RT (3 times/week) in combination with cheese supplementation. Participants received 108 g (LG), 216 g (MG), or 324 g (HG) of cheese on the day of RT, and each serving (108 g) of cheese contained 6.7 g of food-borne protein. The RT program was a whole-body program with movements such as chest presses, leg presses, seated rowing, knee extensions and triceps pushdown. The exercise consisted of 3 sets of 8–12 repetitions at 70%RM, with a 120-s break in between. Body parameters (body composition, lipid profile and muscle strength) were assessed at baseline and after the 4 weeks of the intervention. The feces sample was taken every weekend. A two-way (group × time) mixed-design ANOVA was used to examine the body parameters. Independent one-way ANOVA was used to analyze the differences between groups in baseline characteristics and different values of each parameter. ResultsHDL-C level was higher in MG than in LG. In comparison to LG, MG had lower levels of total cholesterol, low-density lipoprotein cholesterol, body weight, body mass index, body fat mass and body fat percentage. However, there was no difference in muscle strength between in the four groups. The abundance of Actinobacteria was higher in LG and Erysipelotrichaceae was lower in MG and HG. ConclusionThe findings suggest that cheese could be a readily available food-borne protein supplement to enhance the beneficial effects of RT on health. It may improve body composition and lipid profile by altering the proportion of intestinal microbiota. During the 4-week RT intervention, 13.4 g of foodborne protein in the form of cheese 3 times per week was the ideal dosage.

Reliability and validity of a non-linear index of heart rate variability to determine intensity thresholds.

Exercise intensity distribution is crucial for exercise individualization, prescription, and monitoring. As traditional methods to determine intensity thresholds present limitations, heart rate variability (HRV) using DFA a1 has been proposed as a biomarker for exercise intensity distribution. This index has been associated with ventilatory and lactate thresholds in previous literature. This study aims to assess DFA a1's reliability and validity in determining intensity thresholds during an incremental cycling test in untrained healthy adults. Sixteen volunteers (13 males and 3 females) performed two identical incremental cycling stage tests at least 1week apart. First and second ventilatory thresholds, lactate thresholds, and HRV thresholds (DFA a1 values of 0.75 and 0.5 for HRVT1 and HRVT2, respectively) were determined in heart rate (HR), relative oxygen uptake (VO2rel), and power output (PO) values for both tests. We used intraclass correlation coefficient (ICC), change in mean, and typical error for the reliability analysis, and paired t-tests, correlation coefficients, ICC, and Bland-Altman analysis to assess the agreement between methods. Regarding reliability, HRV thresholds showed the best ICCs when measured in PO (HRVT1: ICC = .87; HRVT2: ICC = .97), comparable to ventilatory and lactate methods. HRVT1 showed the strongest agreement with LA 2.5 in PO (p = 0.09, r = .93, ICC = .93, bias = 9.9 ± 21.1), while HRVT2 reported it with VT2 in PO (p = 0.367, r = .92, ICC = .92, bias = 5.3 ± 21.9). DFA a1 method using 0.75 and 0.5 values is reliable and valid to determine HRV thresholds in this population, especially in PO values.

Acute effects of resistance training at different range of motions on plantar flexion mechanical properties and force

ABSTRACT The effects obtained from resistance training depend on the exercise range of motion (ROM) performed. We aimed to examine the acute effects of different exercise ROM resistance training on the plantar flexor muscles. Eighteen healthy untrained male adults participated in three conditions: calf raises in 1) partial condition [final (short muscle length) partial ROM], 2) full condition (full ROM), and 3) control condition. The ankle dorsiflexion (DF) ROM, passive torque at DF ROM, passive stiffness of muscle-tendon unit, and maximal voluntary isometric contraction (MVC-ISO) torque were measured before and immediately after the interventions. There were significant increases in DF ROM, passive torque at DF ROM, and a decrease in MVC-ISO, but no significant interaction in passive stiffness. Post hoc test, DF ROM demonstrated moderate magnitude increases in the full condition compared to the partial (p = 0.023, d = 0.74) and control (p = 0.003, d = 0.71) conditions. Passive torque at DF ROM also showed moderate magnitude increases in the full condition compared to the control condition (p = 0.016, d = 0.69). MVC-ISO had a moderate magnitude decrease in the full condition compared to the control condition (p = 0.018, d=−0.53). Resistance training in the full ROM acutely increases joint ROM to a greater extent than final partial ROM, most likely due to stretch tolerance.