Untrained Healthy Adults Research Articles

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

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.

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.

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.

Endocannabinoid and psychological responses to acute resistance exercise in trained and untrained adults.

This study examined the effects of acute resistance exercise on circulating endocannabinoid (eCB) and mood responses in trained and untrained healthy adults. Thirty-two healthy adults (22.1 ± 2.9 years) were recruited from trained (reporting resistance exercise at least twice per week for ≥ previous three months) and untrained (performing no resistance exercise for ≥ previous three months) groups. Participants (13 male, 19 female) completed three sets of resistance exercise (16 repetitions at 50% 1-repetition max, 12 repetitions at 70% 1-repetition max, 8 repetitions at 80% 1-repetition max). Resistance machines targeted the legs, chest, back, and abdominal muscles. Mood states, affect, and circulating eCB concentrations were evaluated before and after resistance exercise. There were significant decreases in AEA, PEA, and OEA levels following acute resistance exercise (p <0.05; ds = -0.39, -0.48, -0.65, respectively), with no significant group differences or group by time interactions. 2-AG did not change significantly. Positive affect increased significantly following resistance exercise (p = 0.009), while negative affect decreased (p <0.001). Depressive symptoms, anger, confusion, and total mood disturbance decreased significantly (p <0.05), while vigor increased significantly following resistance exercise (p = 0.005). There were no significant group differences or group by time interactions for any psychological outcomes. These results indicate that acute resistance exercise may reduce eCB and related lipid concentrations, which is opposite to the increase in lipids typically observed with acute aerobic exercise. Furthermore, psychological improvements occur after resistance exercise regardless of decreases in eCBs, supporting the notion that psychological changes with exercise likely occur through a wide variety of biological and environmental mechanisms.

The Association of Fatigue With Decreasing Regularity of Locomotion During an Incremental Test in Trained and Untrained Healthy Adults

Fatigue is a key factor that affects human motion and modulates physiology, biochemistry, and performance. Prolonged cyclic human movements (locomotion primarily) are characterized by a regular pattern, and this extended activity can induce fatigue. However, the relationship between fatigue and regularity has not yet been extensively studied. Wearable sensor methodologies can be used to monitor regularity during standardized treadmill tests (e.g., the widely used Bruce test) and to verify the effects of fatigue on locomotion regularity. Our study on 50 healthy adults [27 males and 23 females; <40 years; five dropouts; and 22 trained (T) and 23 untrained (U) subjects] showed how locomotion regularity follows a parabolic profile during the incremental test, without exception. At the beginning of the trial, increased walking speed in the absence of fatigue is associated with increased regularity (regularity index, RI, a. u., null/unity value for aperiodic/periodic patterns) up until a peak value (RI = 0.909 after 13.8 min for T and RI = 0.915 after 13.4 min for U subjects; median values, n. s.) and which is then generally followed (after 2.8 and 2.5 min, respectively, for T/U, n. s.) by the walk-to-run transition (at 12.1 min for both T and U, n. s.). Regularity then decreases with increased speed/slope/fatigue. The effect of being trained was associated with significantly higher initial regularity [0.845 (T) vs 0.810 (U), p < 0.05 corrected], longer test endurance [23.0 min (T) vs 18.6 min (U)], and prolonged decay of locomotor regularity [8.6 min (T) vs 6.5 min (U)]. In conclusion, the monitoring of locomotion regularity can be applied to the Bruce test, resulting in a consistent time profile. There is evidence of a progressive decrease in regularity following the walk-to-run transition, and these features unveil significant differences among healthy trained and untrained adult subjects.

Effects of black vinegar beverage intake on exercise-induced fatigue in untrained healthy adults: a randomized, double-blind, placebo-controlled trial

Effects of black vinegar beverage intake on exercise-induced fatigue in untrained healthy adults: a randomized, double-blind, placebo-controlled trial

Effects of Small-Sided Soccer Games on Physical Fitness, Physiological Responses, and Health Indices in Untrained Individuals and Clinical Populations: A Systematic Review.

Small-sided soccer games (SSSG) are a specific exercise regime with two small teams playing against each other on a relatively small pitch. There is evidence from original research that SSSG exposure provides performance and health benefits for untrained adults. The aim of this systematic review was to summarize recent evidence on the acute and long-term effects of SSSG on physical fitness, physiological responses, and health indices in healthy untrained individuals and clinical populations. This systematic literature search was conducted in four electronic databases (PubMed, Web of Science, SPORTDiscus) from inception until June 2019. The following key terms (and synonyms searched for by the MeSH database) were included and combined using the operators "AND", "OR", "NOT": ((soccer OR football) AND ("soccer training" OR "football training" OR "soccer game*" OR "small-sided soccer game*") AND ("physical fitness" OR "physiological adaptation*" OR "physiological response*" OR health OR "body weight" OR "body mass" OR "body fat" OR "bone composition" OR "blood pressure")). The search syntax initially identified 1145 records. After screening for titles, abstracts, and full texts, 41 studies remained that examined the acute (7 studies) and long-term effects (34 studies) of SSSG-based training on physical fitness, physiological responses, and selected alth indices in healthy untrained individuals and clinical populations. No training-related injuries were reported in the 41 acute and long-term SSSG studies. Typically, a single session of SSSG lasted 12-20min (e.g., 3 × 4 min with 3min rest or 5 × 4min with 4 min rest) involving 4-12 players (2 vs. 2 to 6 vs. 6) at an intensity ≥ 80% of HRmax. Following single SSSG session, high cardiovascular and metabolic demands were observed. Specifically, based on the outcomes, the seven acute studies reported average heart rates (HR) ≥ 80% of HRmax (165-175bpm) and mean blood lactate concentrations exceeding 5mmol/l (4.5-5.9mmol/l) after single SSSG sessions. Based on the results of 34 studies (20 with healthy untrained, 10 with unhealthy individuals, and 4 with individuals with obesity), SSSG training lasted between 12 and 16weeks and was performed 2-3 times per week. SSSG had positive long-term effects on physical fitness (e.g., Yo-Yo IR1 performance), physiological responses including maximal oxygen uptake (VO2max) [+ 7 to 16%], and many health-related markers such as blood pressure (reductions in systolic [- 7.5%] and diastolic [- 10.3%] blood pressure), body composition (decreased fat mass [- 2 to - 5%]), and improved indices of bone health (bone mineral density: [+ 5 to 13%]; bone mineral content: [+ 4 to 5%]), and metabolic (LDL-cholesterol [- 15%] as well as cardiac function (left-ventricular internal diastolic diameter [+ 8%], end diastolic volume [+ 21%], left-ventricular mass index [+ 18%], and left-ventricular ejection fraction [+ 8%]). Irrespective of age or sex, these health benefits were observed in both, untrained individuals and clinical populations. In conclusion, findings from this systematic review suggest that acute SSSG may elicit high cardiovascular and metabolic demands in untrained healthy adults and clinical populations. Moreover, this type of exercise is safe with positive long-term effects on physical fitness and health indices. Future studies are needed examining the long-term effects on physical fitness and physiological adaptations of different types of SSSG training (e.g., 3 vs. 3; 6 vs. 6) in comparison to continuous or interval training in different cohorts.

Comparison of responses to treadmill exercise listening to Thai contemporary music and no music in untrained adult

Living an active lifestyle is important to stay healthy especially in the aging society. Present studies showed Listening to music while exercising can enhance work capacity and delay fatigue. However, most of the research were conducted in trained subjects and used western music such as classical music, which were not familiar in Asian countries. This study aimed to investigate the effect of Thai contemporary music on response of treadmill exercise in untrained adults. Thirty untrained healthy adults were equally allocated to one of the two sequence groups. The first group was listening to Thai contemporary music selected from four types of music while performing treadmill exercise at 60% of maximal heart rate for 20 minutes, washout 1 week then performed treadmill exercise again without listening to music. For the second group, the sequence of treatment was reversed. Rate of Perceived Exertion, SBP, maximum speed, total distant and enjoyment VAS were recorded for each exercise session. Mean RPE was significantly lower while listening to music (11.29) comparing with no music (12.37, P < 0.001). Mean enjoyment VAS was significantly greater while listening to music (6.92) comparing with no music (4.37, P < 0.001). No statistically significant difference regarding SBP, speed and total distant. Thai contemporary music can decrease RPE and increase enjoyment during treadmill exercise at fixed work load, therefore music may be useful as a tool to assist exercise adherence in healthy untrained adults.

Carbohydrate intake and training efficacy – a randomized cross-over study

ABSTRACTCarbohydrate (CHO) availability during endurance exercise seems to attenuate exercise-induced perturbations of cellular homeostasis and might consequently diminish the stimulus for training adaptation. Therefore, a negative effect of CHO intake on endurance training efficacy seems plausible. This study aimed to test the influence of carbohydrate intake on the efficacy of an endurance training program on previously untrained healthy adults. A randomized cross-over trial (8-week wash-out period) was conducted in 23 men and women with two 8-week training periods (with vs. without intake of 50g glucose before each training bout). Training intervention consisted of 4x45 min running/walking sessions/week at 70% of heart rate reserve. Exhaustive, ramp-shaped exercise tests with gas exchange measurements were conducted before and after each training period. Outcome measures were maximum oxygen uptake (VO2max) and ventilatory anaerobic threshold (VT). VO2max and VT increased after training regardless of CHO intake (VO2max: Non-CHO 2.6 ± 3.0 ml*min−1*kg−1 p = 0.004; CHO 1.4 ± 2.5 ml*min−1*kg−1 p = 0.049; VT: Non-CHO 4.2 ± 4.2 ml*min−1*kg−1 p < 0.001; CHO 3.0 ± 4.2 ml*min−1*kg−1 p = 0.003). The 95% confidence interval (CI) for the difference between conditions was between +0.1 and +2.1 ml*min−1*kg−1 for VO2max and between −1.2 and +3.1 for VT. It is concluded that carbohydrate intake could potentially impair the efficacy of an endurance training program.

Effects of Combining Whole-Body Vibration With Exercise on the Consequences of Detraining on Muscle Performance in Untrained Adults

This study investigated whether whole-body vibration (WBV) coupled with low-velocity exercise (EX) for 13 weeks retains muscle performance gains after 5 weeks of subsequent detraining compared with the results of an identical EX program without WBV. Thirty-two untrained healthy adults (22-49 years of age) were randomly assigned to groups that performed EX with or without WBV (EX-WBV and EX, respectively; n = 16 per group). The following outcome variables were evaluated: countermovement jump height; maximal isometric, concentric, and eccentric knee extension strengths; local muscular endurance; and lumbar extension torque before, during, and after the 13-week training period, and after 5 weeks of detraining. Compared with the EX group, significantly higher increases in countermovement jump height and isometric and concentric knee extension strengths were detected in the EX-WBV group after the 13-week training period. However, detraining caused significant declines in these 3 muscle performance tests only in the EX-WBV group (-4.8, -10.2, and -17.2%, respectively), resulting in no significant differences between the test and control groups after the detraining period. After detraining, all examined variables showed significantly better performance compared with pretraining (p < 0.05) and did not significantly differ from midtraining (7 weeks) in both groups (p > 0.05). These results suggest that muscle strength in the lower extremities, particularly isometric and concentric contractions, and muscle power might be more susceptible to short-term detraining effects when exercise is combined with WBV. Thus, it is necessary to perform regular exercise to maximize the benefits of WBV on muscle strength and power during the early stages of training in previously untrained individuals.

Cycling to work: influence on indexes of health in untrained men and women in Flanders. Coronary heart disease and quality of life

The purpose of this study was to examine if a 1-year lifestyle intervention study (cycling to work) has an influence on coronary heart disease (CHD) risk factors and health-related quality of life, in previously untrained healthy adults. Healthy, untrained men and women, who did not cycle to work, participated in an intervention study. Sixty-five subjects (intervention group: IG) were asked to cycle to work at least 3 times a week and 15 controls (CG) were asked not to change their living habits. All measurements were performed on 3 consecutive occasions, with 6 months in between. Physical performance, venous blood samples, blood pressure (BP), and the SF-36 Health Status Survey were assessed. Cycling characteristics and leisure-time physical activities were reported in a dairy. Total cholesterol (TC), LDL, TC/HDL and diastolic BP decreased and HDL increased significantly in the IG. TC and LDL decreased significantly in the CG. Vitality for the total group and physical functioning for women significantly changed over time between IG and CG in the first 6 months. These results show that cycling to work has a positive influence on CHD risk factors and is likely to improve the health-related quality of life in previously untrained healthy adults.

Increased insulin sensitivity and insulin binding to monocytes after physical training.

We studied the effect of physical training on in vivo tissue sensitivity to insulin and insulin binding to monocytes in six previously untrained healthy adults. Physical training (one hour of cycle-ergometer exercise four times per week for six weeks) failed to alter body weight but resulted in a 20 per cent increase (P less than 0.02) in maximal aerobic power (VO2 max) and a 30 per cent increase (P less than 0.01) in insulin-mediated glucose uptake (determined by the insulin clamp technique). The increase in insulin sensitivity correlated directly with the rise in VO2 max (P less than 0.05). Binding of [125I]insulin to monocytes also rose by 35 per cent after physical training (P less than 0.02), primarily because of an increase in the concentration of insulin receptors. Our data indicate that physical training increases tissue sensitivity to insulin in proportion to the improvement in physical fitness. Physical training may have a role in the management of insulin-resistant states, such as obesity and maturity-onset diabetes, that is independent of its effects on body weight.