High-intensity Resistance Research Articles

Study protocol for the ROLEX-DUO randomised placebo-controlled trial: ROmosozumab Loaded with EXercise – DUal effects on bone and muscle in postmenopausal Osteoporosis and Osteopenia

IntroductionNovel strategies are needed to address the rising burden of osteoporosis and fragility fractures. High-intensity resistance and impact (HiRIT) exercise has shown benefit in improving bone density in postmenopausal women...

Differences in knee flexor and extensor force and kinematic variables in rural versus urban area female students in Romania.

The study aimed to identify and explain the typical differences in low-intensity high-volume resistance training (LIHV-RT) performances for major muscle groups between rural versus urban young female students to establish the relevant set of quantitative and qualitative resistance training parameters. The study sample included 46 recreational active female students at the Transilvania University of Brașov, (mean ± SD age, 20 ± 1year; body mass, 60 ± 3kg; height, 160 ± 4cm) grouped urban vs. rural. The study used modified resistance exercise machines for the hamstring- and quadricep-group muscles, equipped with a dynamometer and sensors for identifying developed forces and accelerations. A number of 368 tests were performed, representing two attempts for each subject, for knee flexion and knee extension exercises, with two different loads. For the performance analysis some variables were considered: the maximum number of repetition until failure, maximum force developed, maximum acceleration, the duration of the set and the mean time per repetition. The maximum number of repetition to failure shows a significant higher value for rural than urban in case of knee flexion (d = 0.98 [0.32, 1.54] for load 1(L1) and d = 0.65 [0.03, 1.21] for load 2(L2)) and in case of knee extension (d = 1.89 [1.11, 2.48] for L1 and d = 1.67 [0.92, 2.25] for L2). The total duration of the sets shows a significant higher value for rural than urban in case of knee flexion (d = 0.84 [0.19, 1.39] for L2) and in case of knee extension (d = 1.46 [0.74, 2.03] for L1 and d = 1.56 [0.98, 2.14] for L2). Additionally we found differences in the quality of the relevant repetitions execution and in the impulse developed during the LIHV- MNRF sets. The study's main finding was that there are differences in LIHV-RT performances knee flexion and knee extension antagonistic exercises, between rural and urban female students. We concluded that the obtained results allow teachers to understand the optimal design of RT programs for the different groups of participants, in order to adapt their teaching techniques so that their final objectives are achieved, insisting on particular aspects of the theoretical or practical contents.

Dehydration Decreases Slow Wave Sleep After Heavy Resistance Exercise

Purpose: The purpose of this study was to examine the effects of hydration status on sleep and recovery measurement before and after high volume resistance exercise. It was hypothesized that dehydration decreases sleep and recovery measurements following exercise. Methods: Eight resistance-trained men (age, 21±2 years; weight, 82.0±12.6 kg; height, 177.3±6.9 cm) performed a series of bilateral leg press and knee extensions (RE, 5 sets of 10 repetitions at 80% of 1 repetition maximum). Participants completed one trial in a euhydrated state (EUH; urine specific gravity (USG) < 1.020) and the other in a dehydrated state (DEH: USG ≥ 1.020) which was separated by 2 weeks. For the DEH trial, participants were restricted from consuming fluids for 24 hours prior to the RE and were only permitted to drink 1.5 L of water post-exercise for the remainder of the day. For the EUH trial, participants were instructed to consume fluid for 24 hours prior to and 24 hours post RE to maintain euhydration. Sleep and recovery measurements were collected from a wearable sleep device that participants wore the night before (PRE) and after RE (POST). Repeated measures ANOVAs were used to identify the differences between EUH and DEH. Effect size (ES) was calculated with resulting effects identified as either small (0.2-0.49), medium (0.5-0.79), or large (>0.8) effects. Results: Slow wave sleep (SWS) (POST EUH, 1.4±0.5 hr; POST DEH, 1.0±0.5 hr; ES=0.8; p=0.028) and %SWS (POST EUH, 21.8±3.7 %; POST DEH, 14.3±6.4 %; ES=1.4; p=0.016) were greater in DEH compared to EUH at the night following RE. Also, SWS decreased at POST compared to PRE in DEH (PRE DEH, 1.4±0.3hr; ES=1.0; p=0.028), but not in EUH (PRE EUH, 1.2±0.6 hr; p=0.061). Sleep duration, sleep effciency, sleep disturbance, sleep deprivation, rapid eye movement sleep (REM), %REM, light sleep, resting heart rate, and heart rate variability were not different between EUH and DEH ( p>0.05). Conclusion: Dehydration decreases slow wave sleep following heavy RE, which potentially impairs recovery from exercise as SWS is important for physiological recovery. Therefore, it is critical to maintain euhydration to maximize recovery following an acute bout of RE. This study was funded by National Strength and Conditioning Association (NSCA). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Mitochondrial Biogenesis and Remodeling Protein Response to Bouts of High-load vs High-volume Resistance Training

Introduction: The effects of higher-load (HL; sets of 5 repetitions at 80% of 1-RM) versus higher-volume (HV; sets of 10 repetitions at 60% of 1-RM) resistance training (RT) on various molecular outcomes has proven to be similar between the two paradigms. However, the mitochondrial response to such training paradigms remains understudied. Therefore, the purpose of this study was to interrogate protein level responses of HL vs HV RT in proteins related to mitochondrial biogenesis and remodeling. We hypothesized that HV RT would have a greater effect on mitochondrial markers of biogenesis and remodeling than HL RT. Methods: Fifteen resistance trained males participated in 6 weeks of unilateral RT (single-leg leg press and single-leg leg extension) where each leg was randomly assigned to undergo either the HL or HV RT. Biopsies of the vastus lateralis were collected from both legs at PRE and POST and western blots analysis was used to assess mitochondrial proteins related to biogenesis and remodeling. The data collected were analyzed using two-way within-subject repeated measures ANOVAs. Results: Our results show no statistically significant effect of RT condition on markers of mitochondrial biogenesis and remodeling. However, there was a main effect of time in markers of both mitochondrial biogenesis and remodeling with MFN1 decreasing (p = 0.007, ƞ2 = 0.234) and PINK1 increasing (p = 0.009, ƞ2 = 0.222) from PRE to POST. Conclusion: HL and HV RT paradigms do not differentially affect the mitochondrial markers assessed, and our hypothesis that HV RT would elicit a greater response in markers of mitochondrial biogenesis and remodeling was not supported. However, our data supports the idea that mitochondrial adaptations can be stimulated regardless of the RT paradigm. This discovery could be advantageous for individuals selecting a mode of RT training that is most likely to result in the greatest exercise adherence as well as provide multiple health benefits. Furthermore, research into RT induced mitochondrial adaptations between sexes remains understudied, thus future investigations into these bioenergetic responses is warranted. Funding for assays and participant compensation was provided through discretionary laboratory funds from MR. Additionally, a portion of CG Vann’s effort was funded through the National Institutes of Health (R01AG054840). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

High-Volume Resistance Training Improves Double-Poling Peak Oxygen Uptake in Youth Elite Cross-Country Skiers and Biathletes: A Pilot Study

A total of nineteen elite youth cross-country skiers (16 ± 2 years) were divided into three groups: a low-load group (LL, n = 6) performing 15–20 repetitions per exercise, a high-load group (HL, n = 9) executing 6–12 repetitions, and a control group (CON, n = 4) exclusively engaging in endurance training. Testing included 1RM in upper-body exercises, VO2max running tests, and double-poling (DP) ergometer exhaustion and sprint tests to determine peak oxygen uptake (VO2peak-DP) and peak power (PP). The results indicated that HL and LL showed significant increases in VO2peak-DP, both in absolute values (d = −1.2 and −1.2, p < 0.05) and when normalized to body mass (d = 0.93 and 1.3, p < 0.05). Although there were no group*time effects for VO2peak-DP, PP during DP tests to exhaustion increased in both HL (d = −1.6, p < 0.05) and LL (d = 1.4, p < 0.05) compared to CON. Standardized to body mass, only HL showed significant improvements in PP during the sprint test (d = 1.7, p < 0.05). During the sprint test, both absolute and body-mass-normalized peak power increased only in the high-load group (d = −1.0 and 0.93, p < 0.05). In conclusion, high-load resistance training resulted in the greatest improvements in strength, DP performance, and VO2peak-DP, indicating a dose–response relationship to the load magnitude of resistance training.

Preparation and Study of EPDM Composites with High Volume Resistance Retention Rate

LDPE/ EPDM composites were prepared by mechanical blending method. The effects of two compatibilizers MA/Zn and CPE on the vulcanization properties, mechanical properties, aging resistance and electrical properties of the composites were studied. The results showed that the addition of two kinds of compatibility significantly improved the compatibility of LDPE and EPDM. Compared with CPE, the addition of MA/Zn can improve the properties of the composites better. The mechanical and electrical properties of the composite were improved by the addition of MA/Zn compatibilizer. The volume resistivity of sample L3M2 is the highest at room temperature and 125 ℃, which are 19.8×1013Ω·m and 16.8×1012Ω·m, respectively. Compared with L3, the increase was 26.1% and 25.8%, respectively. The tensile strength is 14.1MPa, which is 90.5% higher than L3.

Construction of micro-nano hybrid structure based on carbon nanotube whisker and alumina for thermally conductive yet electrically insulating silicone rubber composites

High-performance electronics urgently need more effective thermally conductive rubber composites to solve interfacial heat transfer problems in the thermal management systems. Tiny amounts nanocarbon materials (NCM) can significantly improve the thermal conductivity of conventional ceramic-filled rubber composites, but the volume exclusion effect of micrometer ceramic fillers makes NCM highly susceptible to the formation of the conductive pathways, which inevitably leads to the substantial decrease in the volume resistivity of the materials, posing a safety hazard, such as short circuits, to electronic devices. Here, we report an electrostatic self-assembly method to prepare CNW@n-Al2O3 hybrids by loading nano-alumina (n-Al2O3) onto carbon nanotube whiskers (CNW) and co-filling them with micrometer alumina (m-Al2O3) to silicone rubber, constructing a micro-nano-multi-level hybrid network structure, which can fully utilize the high thermal conductivity while shielding the electrical conductivity of CNW. The resulting composite filled with 2 phr of CNW@n-Al2O3 exhibits a significantly enhanced thermal conductivity of 1.137 W/(m·K) and a high volume resistance of 1.323 × 109 Ω cm, and is proved to be used as an excellent thermal interface material to assist the heat dissipation of the microelectronic chip. This study provides a facile and effective strategy for the design of thermally conductive yet electrically insulating rubber composites filled with CNW, which shows a bright application prospect in the thermal management of high-performance electronic devices.

Differences in the recovery response from high-intensity and high-volume resistance exercise on force, reactive agility, and cognitive function

PurposeThis study compared the recovery response of physical performance and cognitive function between high volume, low intensity (HV) and high intensity, low volume (HI) resistance training in resistance trained men.MethodsEight recreationally resistance trained men (27.8 ± 1.6 y; 85.5 ± 11.2 kg; 178.4 ± 8.3 cm), with at least one-year of resistance training experience (6.4 ± 3.9 y) participated in this cross-over design study. Participants were randomly assigned to either HV (6-sets of 15–20 repetitions at 60% of the participant’s one-repetition maximum (1RM), 1-min rest between sets) or HI (6-sets of 3–5 repetitions at 90% 1RM, 3-min rest between sets). Following a one-week recovery period, participants reported back to the laboratory and performed the other training session. Cognitive function (SCAT5), physical performance (isometric mid-thigh pull), and reactive agility measures were assessed at baseline, immediately-post (IP) and at 30- (30P) and 60-minutes post-exercise.ResultsParametric analysis revealed no differences in peak force (p = 0.423), and the rate of force development at 200 ms (p = 0.827) and 250 ms (p = 0.797) between HI and HV. However, magnitude-based inference (MBI) analysis indicated that peak force was possibly decreased at 30P following HI and that reactive agility was likely negatively impacted at IP following HV. Friedman analysis indicated a significant decline (p = 0.035) in delayed memory during HV at IP and 30P.ConclusionsResults of this study indicate that participants engaging in HV resistance training are more susceptible to experiencing performance declines in reaction time and cognitive function than HI training. These findings shed light on differences in physical and cognitive function recovery from HI and HV training programs.

Therapeutic Photobiomodulation Before Strenuous Exercise Attenuates Shoulder Muscle Fatigue.

Photobiomodulation therapy (PBMT) applied as a preconditioning treatment before exercise has been shown to attenuate fatigue and improve skeletal muscle contractile function during high-intensity resistance exercise. Practical implications for preconditioning muscles with PBMT before fatiguing exercise include a safe and noninvasive means to enhance performance and reduce the risk of musculoskeletal injury. To examine the muscle fatigue-attenuating effects of PBMT on performance of the shoulder external-rotator muscle group when applied as a preconditioning treatment before high-intensity, high-volume resistance exercise. Sham-controlled, crossover design. Laboratory. Twenty healthy men (n = 8) and women (n = 12) between the ages of 18 and 30 years. Photobiomodulation therapy was administered using a near-infrared laser (λ = 810/980 N·m, 1.8 W/cm2, treatment area = 80-120 cm2) to the shoulder external-rotator muscles at a radiant exposure of 10 J/cm2. Participants performed 12 sets of isokinetic shoulder exercise. Each set consisted of 21 concentric contractions of internal and external rotation at 60°/s. The sets were subdivided into 3 blocks of exercise (block 1: sets 1-4; block 2: sets 5-8; block 3: sets 9-12). Normalized peak torque (N·m/kg), average peak torque (N·m), total work (N·m), and average power (W). During the last block of exercise (sets 9-12), all performance measures for the active PBMT condition were 6.2% to 10% greater than the sham PBMT values (P < .02 to P < .001). Photobiomodulation therapy attenuated fatigue and improved muscular performance of the shoulder external rotators in the latter stages of strenuous resistance exercise.

Synthesis and electrochemical properties of porous carbon materials from sludge sources

Anaerobic digestion sludge technology is a green and efficient method of treating sludge. However, the presence of humic acid (HA) in sludge can inhibit methanogenic efficiency, and it is necessary to reduce its impact on biogas production by removal or pretreatment. HA, a graphene oxide material can be used to produce high-performance energy-storage materials. Thus, this study examined the sludge source of HA as a precursor, and different electrode materials were prepared by varying the reaction conditions. The structure and electrochemical properties of the electrode materials were analyzed. The results showed that the electrode material prepared using KOH as an activator at 700 °C exhibited optimal performance, with a high specific surface area (1480.53 m2·g−1), pore volume (0.943 cm3·g−1), specific capacitance (185.9 F·g−1), and equivalent series resistance (0.73 Ω). The material maintained 97.8% of its specific capacitance after 1000 cycles at a current density of 1 A·g−1 with benign cycle stability. This study confirmed that the production of HA as an electrode material at a low cost with good performance presents significant prospects.

METHODS FOR TREATING WASTEWATER FROM ORGANIC POLLUTANTS

Water pollution by organic and inorganic compounds, heavy metals, dyes, radioactive and pharmaceutical compounds has a significant impact on its use. Globalization, structural changes, economic development around the world-all this contributes to the release of pollutants that cause water pollution. That is why wastewater treatment and recovery, removing pollutants from wastewater and wastewater, is one of the most important issues. This literature review examines the problems of water pollution, its sources and types of pollutants found in water, and also discusses purification methods, including methods of water purification from pollutants, in particular phenol, in the presence of nanocomposite catalysts. Recently, more and more attention has been paid to applied nanotechnology using magnetic and carbon nanocomposites due to the advantages of production cost, high surface area, pore volume and environmental sustainability. The literature review focuses on magnetic nanocomposite catalysts based on alternating and rare earth metals with advantages such as low cost of preparation for water disinfection, high surface area, pore volume and environmental resistance. Magnetic carbon nanocomposites usually demonstrate excellent adsorption characteristics of pollutants from aqueous solutions, therefore, the expansion of the use of nanotechnology in water purification is of great importance.

Physical Exercise Program for Osteoporosis in the Elderly: Literature Review

Low bone mass and damage to the microarchitecture of bone tissue are two characteristics of osteoporosis, a systemic bone disease that can raise the risk of fractures. At every stage of life, increasing physical activity positively affects bone health, whereas reducing physical activity can cause bone loss. The purpose of this study was to analyze the effect of a physical exercise program for osteoporosis in the elderly. The technique is a literature review that involves looking for relevant publications using keywords. The inclusion criteria for this study were that the participants in the study were elderly subjects, that the results of the study measured or analyzed the physical exercise program in elderly subjects with osteoporosis, that the study used quasi experiment methods, randomized controlled trials, and cross sectional, that the year of publication of the study was in the time period of 2013–2022, and that the research was conducted in both Indonesian and English. The review's findings indicate that there are six papers that examine physical exercise programs for the elderly, including weight-bearing exercises, balance training, resistance training, and high-intensity resistance and impact training. These exercises can all be performed and have a favorable effect on the elderly. Even if there is no evidence to support the existence of dangers such fractures in physical training programs, it is nevertheless necessary to provide assistance in order to decrease risks.

Vegan and Omnivorous High Protein Diets Support Comparable Daily Myofibrillar Protein Synthesis Rates and Skeletal Muscle Hypertrophy in Young Adults

BackgroundIt remains unclear whether non–animal-derived dietary protein sources (and therefore vegan diets) can support resistance training-induced skeletal muscle remodeling to the same extent as animal-derived protein sources. MethodsIn Phase 1, 16 healthy young adults (m = 8, f = 8; age: 23 ± 1 y; BMI: 23 ± 1 kg/m2) completed a 3-d dietary intervention (high protein, 1.8 g·kg bm−1·d−1) where protein was derived from omnivorous (OMNI1; n = 8) or exclusively non-animal (VEG1; n = 8) sources, alongside daily unilateral leg resistance exercise. Resting and exercised daily myofibrillar protein synthesis (MyoPS) rates were assessed using deuterium oxide. In Phase 2, 22 healthy young adults (m = 11, f = 11; age: 24 ± 1 y; BMI: 23 ± 0 kg/m2) completed a 10 wk, high-volume (5 d/wk), progressive resistance exercise program while consuming an omnivorous (OMNI2; n = 12) or non–animal-derived (VEG2; n = 10) high-protein diet (∼2 g·kg bm−1·d−1). Muscle fiber cross-sectional area (CSA), whole-body lean mass (via DXA), thigh muscle volume (via MRI), muscle strength, and muscle function were determined pre, after 2 and 5 wk, and postintervention. ObjectivesTo investigate whether a high-protein, mycoprotein-rich, non-animal-derived diet can support resistance training-induced skeletal muscle remodeling to the same extent as an isonitrogenous omnivorous diet. ResultsDaily MyoPS rates were ∼12% higher in the exercised than in the rested leg (2.46 ± 0.27%·d−1 compared with 2.20 ± 0.33%·d−1 and 2.62 ± 0.56%·d−1 compared with 2.36 ± 0.53%·d−1 in OMNI1 and VEG1, respectively; P < 0.001) and not different between groups (P > 0.05). Resistance training increased lean mass in both groups by a similar magnitude (OMNI2 2.6 ± 1.1 kg, VEG2 3.1 ± 2.5 kg; P > 0.05). Likewise, training comparably increased thigh muscle volume (OMNI2 8.3 ± 3.6%, VEG2 8.3 ± 4.1%; P > 0.05), and muscle fiber CSA (OMNI2 33 ± 24%, VEG2 32 ± 48%; P > 0.05). Both groups increased strength (1 repetition maximum) of multiple muscle groups, to comparable degrees. ConclusionsOmnivorous and vegan diets can support comparable rested and exercised daily MyoPS rates in healthy young adults consuming a high-protein diet. This translates to similar skeletal muscle adaptive responses during prolonged high-volume resistance training, irrespective of dietary protein provenance.This trial was registered at clinicaltrials.gov as NCT03572127.

Effect of High-Intensity vs. Moderate-Intensity Resistance Training on Strength, Power, and Muscle Soreness in Male Academy Soccer Players.

McQuilliam, SJ, Clark, DR, Erskine, RM, and Brownlee, TE. The effect of high vs. moderate-intensity resistance training on strength, power and muscle soreness in male academy soccer players. J Strength Cond Res 37(6): 1250-1258, 2023-The aims of this study were to investigate the impact of high-intensity, low-volume (HRT) vs . moderate-intensity, and high-volume resistance training (MRT) vs . soccer training only (control group [CON]) on changes in strength, power, and speed and to compare delayed onset muscle soreness (DOMS) between groups in male academy soccer players (ASP). Twenty-two ASP (age: 18 ± 1 years) were assigned to HRT ( n = 8), MRT ( n = 7), or CON ( n = 7). High-intensity resistance training completed 2 sets of 4 repetitions parallel back squat (PBS) repetitions at 90% 1 repetition maximum (1RM), while MRT performed 3 sets of 8 repetitions PBS repetitions at 80% 1RM, both once a week for 6 weeks in-season, alongside regular soccer training. All groups completed the following pretraining and posttraining assessments: 3RM PBS, bilateral vertical and horizontal countermovement jumps (CMJ), squat jump (SJ), and 30-m sprint. Delayed onset muscle soreness was assessed using a visual analog scale throughout training. High-intensity resistance training and MRT experienced similar increases compared with CON in absolute PBS 3RM ( p < 0.001), SJ height ( p = 0.001), and CMJ height ( p = 0.008) after training. There was a greater increase in PBS 3RM relative to body mass after HRT than MRT and CON ( p = 0.001) and horizontal CMJ distance improved in HRT but not in MRT or CON ( p = 0.011). There was no change in 10-m, 20-m, or 30-m sprint performance in any group. High-intensity resistance training volume was 58 ± 15% lower than that of MRT ( p < 0.001), and DOMS measured throughout training did not differ between groups ( p = 0.487). These findings suggest that 1 HRT session a week may be an efficient method for improving strength and power in ASP in-season with minimal DOMS.

Synthesis of Pd-Fe2O3 nanoflakes nanocomposite for superior energy storage device

BackgroundThe synthesized nanocomposites have enhanced stability due to the composite effect, high surface area, pore volume, and low charge transfer resistance of the nanocomposite. Moreover, the prepared nanocomposites reveal excellent specific capacitance, fast charge-discharge, and long-term durability. MethodThe Pd-Fe2O3 nanoflakes nanocomposite has been prepared by the simple redox reaction under hydrothermal conditions. Significant findingsThe as-synthesized Pd-Fe2O3 nanoflakes nanocomposite shows excellent capacitance of 531 F g−1 at a current density of 1 A g−1 under acidic electrolyte whereas, the commercial Fe2O3 shows only 215 F g−1. The charge-storage mechanism of as-synthesized nanocomposite shows the major capacitive contribution to store the total charge. Further, a solid-state asymmetric supercapacitor device fabricated and exhibits excellent capacitance of 137 F g−1 at 1 A g−1 current density using PVA-H2SO4 gel electrolyte along with a maximum energy density of 61.65 Wh kg−1 and power density of 3.5 kW kg−1. Interestingly, the as-synthesized Pd-Fe2O3 nanoflakes nanocomposite shows outstanding stability up to 8000 continuous charge-discharge cycles using the acidic electrolyte. The retention-specific capacitance of the nanocomposite is found to be 87% after cycles stability.

1370-P: Effects of Concomitant High-Intensity Interval Training or Resistance Exercise Training on Muscle Protein Synthesis, Body Composition, and Metabolic Markers following 6-Week VLCD among Healthy Overweight/Obese Men

Background: Very Low-Calorie Diet (VLCD) is effective for rapid weight loss but is associated with lean mass (LM) loss. Resistance exercise training (RET) and high-intensity interval training (HIIT) are known to promote muscle hypertrophy or improvements in cardiopulmonary fitness (CPF) . We therefore explored the effects of VLCD with or without RET or HIIT on body composition, metabolic markers, and CPF. Methods: Participants were randomly allocated into VCLD only (n=10; 46±8y; 104±12kg; BMI 32±4, mean±SD) , VLCD+RET (n= 8; 40±8y;99k±10kg; BMI 32±2) or VLCD+HIIT (n=8; 46±11y; 101±12kg; BMI 33±3) . All groups had six weeks of VLCD. Exercise groups had supervised training three times/week. Pre- and post-interventions assessment included DXA scan, lipid profiles, insulin sensitivities, blood pressure, cardiopulmonary exercise test and biopsy of vastus lateralis muscle for muscle protein synthesis (MPS) using deuterium oxide technique. Results: Significant reduction in body weight (-11.1±3 kg, -10.8±4kg, -11.7±4kg) , fat mass (-6.8±2kg, -6.9±2kg, -7.7±3kg, and LM (-4.3±2kg, -3.9±2kg, -4±1kg) were seen for VLCD only, VLCD+RET and VLCD+HIIT respectively (P&amp;lt;0.0001) , with no between-groups difference. MPS rate following interventions were 0.8%±0.2d-1, 0.9%±0.2d-1 and 1.2%±0.2d-1 (statistically higher in VLCD+HIIT compared to VLCD only; P=0.004) . Significant improvements were seen in metabolic markers (insulin sensitivities, lipid profiles and blood pressure) in all groups, with no inter-group difference. No intra- and inter-groups differences were seen for VO2max or anaerobic threshold. Conclusion: VLCD with or without exercise induced marked weight loss, improved insulin sensitivities, and metabolic markers despite LM loss. HIIT was associated with significant improvement in MPS and may be used as an adjunct to preserve VLCD induced LM loss. Disclosure M.Abdul aziz: None. I.Ramzan: None. N.Gharahdaghi: None. M.Brook: None. D.J.Wilkinson: None. B.E.Phillips: None. K.Smith: None. P.J.Atherton: None. I.R.Idris: None.

New textile material—spider silk fiber

Abstract Environmental protection and sustainable development are two important topics that draw great concern to the world since various synthetic polymer textile materials have caused environmental pollution to the earth, thus, we need to find new and environmentally friendly materials. Spider silk belongs to polymer material that enjoys favorable reproducibility. Besides, its physical and chemical properties are superior to silk fibers, other natural fibers and most synthetic fibers. Its surface is smooth and soft, lustrous and sheen, it also possesses the characteristics of low temperature resistance, strong tenacity, high intensity, high elasticity, high density and fracture resistance which can be applied to body armors, medical sutures, costumes, etc. As a new kind of textile material, spider silk is environmentally friendly which may bring infinite potential.

The time course of different neuromuscular adaptations to short-term downhill running training and their specific relationships with strength gains

PurposeDue to its eccentric nature, downhill running (DR) training has been suggested to promote strength gains through neuromuscular adaptations. However, it is unknown whether short-term chronic DR can elicit such adaptations.MethodsTwelve untrained, young, healthy adults (5 women, 7 men) took part in 4 weeks’ DR, comprising 10 sessions, with running speed equivalent to 60–65% maximal oxygen uptake (dot{V}O2max, assessed at weeks 0 and 4). Isometric and isokinetic knee-extensor maximal voluntary torque (MVT), vastus lateralis (VL) muscle morphology/architecture (anatomical cross-sectional area, ACSA; physiological CSA, PCSA; volume; fascicle length, Lf; pennation angle, PA) and neuromuscular activation (VL EMG) were assessed at weeks 0, 2 and 4.ResultsMVT increased by 9.7–15.2% after 4 weeks (p < 0.01). VL EMG during isometric MVT increased by 35.6 ± 46.1% after 4 weeks (p < 0.05) and correlated with changes in isometric MVT after 2 weeks (r = 0.86, p = 0.001). VL ACSA (+2.9 ± 2.7% and +7.1 ± 3.5%) and volume (+2.5 ± 2.5% and +6.6 ± 3.2%) increased after 2 and 4 weeks, respectively (p < 0.05). PCSA (+3.8 ± 3.3%), PA (+5.8 ± 3.8%) and Lf (+2.7 ± 2.2%) increased after 4 weeks (p < 0.01). Changes in VL volume (r = 0.67, p = 0.03) and PCSA (r = 0.71, p = 0.01) correlated with changes in concentric MVT from 2 to 4 weeks. dot{V}O2max (49.4 ± 6.2 vs. 49.7 ± 6.3 mL·kg−1·min−1) did not change after 4 weeks (p = 0.73).ConclusionJust 4 weeks’ moderate-intensity DR promoted neuromuscular adaptations in young, healthy adults, typically observed after high-intensity eccentric resistance training. Neural adaptations appeared to contribute to most of the strength gains at 2 and 4 weeks, while muscle hypertrophy seemed to contribute to MVT changes from 2 to 4 weeks only.

HIIT and Resistance Training Effects on Learning-related Outcomes in Underserved School Children

Research has demonstrated associations between differing modalities of physical activity (PA) and behavioral and learning outcomes; however, little evidence exists in real world settings. To evaluate the effects of embedding high intensity interval training (HITT) and resistance training (RT) into physical education (PE) curriculum on PA, academic performance, and behavior in youth attending urban schools. Forty boys and 30 girls; ages 8-10 yrs. enrolled in an expanded public school supplemental learning program were assigned into one of three conditions using a pragmatic trial design: standard PE curriculum (n = 23), HITT (n = 25), and RT (n = 22). PA was measured using accelerometers; math achievement scores were conducted at baseline and post-intervention using the Math Knowledge Assessment (MKA); behavior was assessed using the Abbreviated Conners Rating Scale (ACRS) daily. Participation in HITT resulted in 1.86 additional vigorous PA minutes (p=0.04) and 0.76 additional very vigorous PA minutes (P=0.02) per session, but was not associated with increased moderate PA minutes compared to the control group. RT PA outcomes did not differ from regular PE. Participating in HIIT, but not RT, was associated with a 1.82-point improvement in math test scores compared to those in the same grade in the standard PE group (p=0.02). No group assignment was associated with behavioral ratings. Embedding HITT within PE has potential for improving vigorous PA levels and may affect learning outcomes in urban youth. This is consistent with prior studies which show how short bouts of intense exercise can improve cognitive outcomes.

The effect of low-intensity whole-body vibration with or without high-intensity resistance and impact training on risk factors for proximal femur fragility fracture in postmenopausal women with low bone mass: study protocol for the VIBMOR randomized controlled trial

BackgroundThe prevailing medical opinion is that medication is the primary (some might argue, only) effective intervention for osteoporosis. It is nevertheless recognized that osteoporosis medications are not universally effective, tolerated, or acceptable to patients. Mechanical loading, such as vibration and exercise, can also be osteogenic but the degree, relative efficacy, and combined effect is unknown. The purpose of the VIBMOR trial is to determine the efficacy of low-intensity whole-body vibration (LIV), bone-targeted, high-intensity resistance and impact training (HiRIT), or the combination of LIV and HiRIT on risk factors for hip fracture in postmenopausal women with osteopenia and osteoporosis.MethodsPostmenopausal women with low areal bone mineral density (aBMD) at the proximal femur and/or lumbar spine, with or without a history of fragility fracture, and either on or off osteoporosis medications will be recruited. Eligible participants will be randomly allocated to one of four trial arms for 9 months: LIV, HiRIT, LIV + HiRIT, or control (low-intensity, home-based exercise). Allocation will be block-randomized, stratified by use of osteoporosis medications. Testing will be performed at three time points: baseline (T0), post-intervention (T1; 9 months), and 1 year thereafter (T2; 21 months) to examine detraining effects. The primary outcome measure will be total hip aBMD determined by dual-energy X-ray absorptiometry (DXA). Secondary outcomes will include aBMD at other regions, anthropometrics, and other indices of bone strength, body composition, physical function, kyphosis, muscle strength and power, balance, falls, and intervention compliance. Exploratory outcomes include bone turnover markers, pelvic floor health, quality of life, physical activity enjoyment, adverse events, and fracture. An economic evaluation will also be conducted.DiscussionNo previous studies have compared the effect of LIV alone or in combination with bone-targeted HiRIT (with or without osteoporosis medications) on risk factors for hip fracture in postmenopausal women with low bone mass. Should either, both, or combined mechanical interventions be safe and efficacious, alternative therapeutic avenues will be available to individuals at elevated risk of fragility fracture who are unresponsive to or unwilling or unable to take osteoporosis medications.Trial registrationAustralian New Zealand Clinical Trials Registry (www. anzctr.org.au) (Trial number ANZCTR12615000848505, https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id = 368962); date of registration 14/08/2015 (prospectively registered). Universal Trial Number: U1111-1172-3652.