Effect of resistance training with different frequencies and subsequent detraining on muscle mass and appendicular lean soft tissue,IGF-1, and testosterone in older women

Objective: To analyse the effect of resistance training (RT) frequency on muscle mass, appendicular lean soft tissue, insulin-like growth factor 1 (IGF-1), testosterone, and their changes with detraining in older women. Methods: Forty-five physically independent older women (≥ 60?years) were randomly assigned to perform RT either two (G2X, n = 21) or three times/week (G3X, n = 24), during 12?weeks (8 exercises, 1 set of 10–15 repetition maximum). Muscle mass and appendicular lean soft tissue, IGF-1, testosterone, and dietary intake were measured at pre-training, post-training, and after detraining (12?weeks). Results: Muscle mass and appendicular lean soft tissue significantly increased post-training (G2X?=?+5.5% and G3X?=?+5.8%, P?P?P?Conclusion: We conclude that lower RT frequency is as effective as higher frequency to improve muscle mass and appendicular lean soft tissue, and to maintain testosterone and IGF-1. Additionally, detraining may reduce testosterone regardless of RT frequency. These results are specifically for community-dwelling older women and may not be generalized to other populations.     

Effects of different intensities of resistance training with equated volume load on muscle strength and hypertrophy

The present study investigated the effects of different intensities of resistance training (RT) on elbow flexion and leg press one-repetition maximum (1RM) and muscle cross-sectional area (CSA). Thirty men volunteered to participate in an RT programme, performed twice a week for 12 weeks. The study employed a within-subject design, in which one leg and arm trained at 20% 1RM (G20) and the contralateral limb was randomly assigned to one of the three conditions: 40% (G40); 60% (G60), and 80% 1RM (G80). The G20 started RT session with three sets to failure. After G20 training, the number of sets was adjusted for the other contralateral limb conditions with volume-matched. CSA and 1RM were assessed at pre, post-6 weeks, and post-12 weeks. There was time effect for CSA for the vastus lateralis (VL) (8.9%, 20.5%, 20.4%, and 19.5%) and elbow flexors (EF) (11.4%, 25.3%, 25.1%, and 25%) in G20, G40, G60, and G80, respectively (p?>?.05). G80 showed higher CSA than G20 for VL (19.5% vs. 8.9%) and EF (25% vs. 11.4%) at post-12 weeks (p?p?相似文献   

Physiological and Anatomical Characteristics Of Outstanding Female Junior Tennis Players

Purpose: The purpose of this study was to investigate the physiological adaptations of resistance training (RT) in prepubertal boys. Methods: Eighteen healthy boys were divided into RT (n = 9, M_age = 10.4 ± 0.5 years) and control (CTR; n = 9, M_age = 10.9 ± 0.7 years) groups. The RT group underwent a resistance training during 12 weeks, 3 times per week, performing 3 sets of 6 to 15 repetitions at intensities ranging from 60% to 80% of maximal dynamic strength (1-repetition maximum [1-RM] values). Before and after the training, the groups were assessed in their body mass and composition (dual-energy X-ray absorptiometry), isokinetic dynamometry, 1-RM, and ergoespirometry. Moreover, force per unit of muscle volume was calculated by the quotient between 1-RM and lean mass. Results: Both groups presented statistically significant (p < .05) increases in the 1-RM and force per unit of muscle volume in the knee extension and elbow flexion, but these strength increases were statistically significantly greater in the RT group (effect size [ES] = 2.83–9.00) than in the CTR group (ES = 0.72–1.00). Moreover, both groups statistically significantly increased in lean body mass variables (ES = 0.12–0.38). However, increases in the fat mass variables occurred only in the CTR group (ES = ? 0.01–0.50), whereas no changes were observed in the RT group. Furthermore, there were statistically significant increases in all bone mineral content variables (ES = 0.13–0.43), without differences between groups. No cardiorespiratory changes were observed. Conclusion: Twelve weeks of RT was effective in improving strength and force per unit of muscle volume and prevented fat mass increases in boys.     

Comparison of the musculoskeletal effects of different iso-inertial resistance training modalities: Flywheel vs. electric-motor

Abstract

This study aimed to analyse whether increasing the eccentric overload (EO) during resistance training, in terms of range of motion and/or velocity using an electric-motor device, would induce different muscle adaptations than conventional flywheel-EO resistance training. Forty physically active university students (21.7?±?3.4 years) were randomly placed into one of the three training groups (EX1, EX2, FW) and a control group without training (n?=?10 per group). Participants in the training groups completed 12 sessions (4 sets of 7 repetitions) of iso-inertial single-leg squat training over 6 weeks for the dominant leg. Resistance was generated either by an electric-motor device at two different velocities for the eccentric phase; 100% (EX1) or 150% (EX2) of concentric speed, or by a conventional flywheel device (FW). Thigh lean tissue mass, unilateral leg press one-repetition maximum (1-RM), unilateral muscle power at different percentages of the 1-RM and bilateral/unilateral vertical jump were assessed before and after the 6-week training. There were significant (p?<?0.05–0.001) main effects of time in the 3 training groups, indicating increased thigh lean tissue mass (2.5–5.8%), 1-RM load (22.4–30.2%), vertical jump performance (9.1–32.9%) and muscle power (8.8–21.7%), without differences across experimental groups. Participants in the control group did not improve any of the variables measured. In addition, EX2 showed greater gains in eccentric average peak power during training than EX1 and FW (p?<?0.001). Despite the different EO offered, 6 weeks of resistance training using flywheel or electric-motor devices induced similar significant gains in muscle mass, strength, muscle power and vertical jump.     

High-frequency resistance training does not promote greater muscular adaptations compared to low frequencies in young untrained men

The aim of the study was to compare the effect of resistance training (RT) frequencies of five times (RT5), thrice- (RT3) or twice- (RT2) weekly in muscle strength and hypertrophy in young men. Were used a within-subjects design in which 20 participants had one leg randomly assigned to RT5 and the other to RT3 or to RT2. 1?RM and muscle cross-sectional area (CSA) were assessed at baseline, after four (W4) and eight (W8) RT weeks. RT5 resulted in greater total training volume (TTV) than RT3 and RT2 (P?=?.001). 1?RM increased similarly between protocols at W4 (RT5: 55?±?9?Kg, effect size (ES): 1.18; RT3: 51?±?11?Kg, ES: 0.80; RT2: 54?±?7?Kg, ES: 1.13; P?P?2, ES: 0.54; RT3: 22.0?±?4.6?cm², ES: 0.19; RT2: ES: 0.25; 23.8?±?3.8?cm²; P?2; ES: 0.69; RT3: 23.6?±?4.2?cm², ES: 0.58; RT2: 25.5?±?3.7?cm²; ES: 0.70; P?2; RT3: 21.2?±?4.0?cm²; RT2: 22.9?±?3.8?cm²). Performing RT5, RT3 and RT2 a week result in similar muscle strength increase and hypertrophy, despite higher TTV for RT5.     

Neural mechanisms of strength increase after one-week motor imagery training

The neural mechanisms explaining strength increase following mental training by motor imagery (MI) are not clearly understood. While gains are mostly attributed to cortical reorganization, the sub-cortical adaptations have never been investigated. The present study investigated the effects of MI training on muscle force capacity and the related spinal and supraspinal mechanisms. Eighteen young healthy participants (mean age: 22.5?±?2.6) took part in the experiment. They were distributed into two groups: a control group (n?=?9) and an MI training group (n?=?9). The MI group performed seven consecutive sessions (one per day) of imagined maximal isometric plantar flexion (4 blocks of 25 trials per session). The control group did not engage in any physical or mental training. Both groups were tested for the isometric maximal plantar flexion torque (MVC) and the rate of torque development (RTD) before and after the training session. In addition, soleus and medial gastrocnemius spinal and supraspinal adaptations were assessed through the recording of H-reflexes and V-waves, with electrical stimulations of the posterior tibial nerve evoked at rest and during MVC, respectively. After one week, only the MI training group increased both plantar flexion MVC and RTD. The enhancement of muscle torque capacity was accompanied by significant increase of electromyographic activity and V-wave during MVC and of H-reflex at rest. The increased cortical descending neural drive and the excitability of spinal networks at rest could explain the greater RTD and MVC after one week of MI training.     

Maximal intended velocity training induces greater gains in bench press performance than deliberately slower half-velocity training

Abstract

The purpose of this study was to compare the effect on strength gains of two isoinertial resistance training (RT) programmes that only differed in actual concentric velocity: maximal (MaxV) vs. half-maximal (HalfV) velocity. Twenty participants were assigned to a MaxV (n = 9) or HalfV (n = 11) group and trained 3 times per week during 6 weeks using the bench press (BP). Repetition velocity was controlled using a linear velocity transducer. A complementary study (n = 10) aimed to analyse whether the acute metabolic (blood lactate and ammonia) and mechanical response (velocity loss) was different between the MaxV and HalfV protocols used. Both groups improved strength performance from pre- to post-training, but MaxV resulted in significantly greater gains than HalfV in all variables analysed: one-repetition maximum (1RM) strength (18.2 vs. 9.7%), velocity developed against all (20.8 vs. 10.0%), light (11.5 vs. 4.5%) and heavy (36.2 vs. 17.3%) loads common to pre- and post-tests. Light and heavy loads were identified with those moved faster or slower than 0.80 m·s^?1 (～60% 1RM in BP). Lactate tended to be significantly higher for MaxV vs. HalfV, with no differences observed for ammonia which was within resting values. Both groups obtained the greatest improvements at the training velocities (≤0.80 m·s^?1). Movement velocity can be considered a fundamental component of RT intensity, since, for a given %1RM, the velocity at which loads are lifted largely determines the resulting training effect. BP strength gains can be maximised when repetitions are performed at maximal intended velocity.     

Effects of resistance training on expression of IGF-I splice variants in younger and older men

Insulin-like growth factor-I (IGF-I) and its splice variants Insulin-like growth factor-I isoform Ea (IGF-IEa) and mechano growth factor (MGF) may play an important role in muscular adaptations to resistance training (RT) that may be modulated by ageing. It has been suggested that IGF-I induces cellular responses via AKT8 virus oncogene cellular homolog (Akt) and Extracellular signal-regulated kinase (Erk) signalling pathways. Therefore, resistance exercise-induced changes in skeletal muscle IGF-IEa and MGF messenger ribonucleic acid (mRNA), and MGF, Erk1/2, Akt and p70S6K protein expression were investigated before and after 21 weeks of RT in younger (YM, 20–34 yrs., n?=?7) and older men (OM, 51–71 yrs., n?=?10). Experimental resistance exercises (RE) of 5?×?10 repetition maximum leg presses were performed pre- and post-RT. Muscle biopsies were obtained before and 48?h after REs, to study the late response to muscle loading. The muscle proteins or mRNAs of interest were not systematically influenced by the REs or RT, except for MGF mRNA expression which was increased (p?相似文献   

The improvement in walking speed induced by resistance training is associated with increased muscular strength but not skeletal muscle mass in older women

Objective: The purpose of the present study was to analyze whether improvements in fast walking speed induced by resistance training (RT) are associated with changes in body composition, muscle quality, and muscular strength in older women. Methods: Twenty-three healthy older women (69.6?±?6.4 years, 64.95?±?12.9?kg, 1.55?±?0.07?m, 27.06?±?4.6?kg/m²) performed a RT program for 8 weeks consisting of 8 exercises for the whole body, 3 sets of 10–15 repetitions maximum, 3 times a week. Anthropometric, body composition (fat-free mass [FFM], skeletal muscle mass [SMM], legs lean soft tissue [LLST], fat mass), knee extension muscular strength (KE1RM), muscle quality index (MQI [KE1RM/LLST]), and 10-meter walking test (10-MWT) were performed before and after the intervention. Results: Significant (P?<?.05) changes were observed from pre- to post-training for FFM (+1.6%), MQI (+7.2%), SMM (+2.4%), LLST (+1.8%), KE1RM (+8.6%), fat mass (?1.4%), and time to perform 10-MWT (?3.7%). The percentage change in 10-MWT was significantly associated with percentage change in MQI (r?=??0.46, P?=?.04) and KE1RM (r?=??0.45, P?=?.04), however not associated percentage of changes in SMM (r?=?0.01, P?=?.97), LLST (r?=??0.22, P?=?.33), and body fat (r?=?0.10, P?=?.66). Conclusion: We conclude that the improvement in the 10-MWT after an 8-week RT program is associated with increases in lower limb muscular strength and muscle quality, but not with muscle mass or body fat changes in older women.     

Maximal strength and cortisol responses to psyching-up during the squat exercise

We studied the effect of psyching-up on one-repetition maximum (1-RM) performance and salivary cortisol responses during the squat exercise. Ten men (age 21.6?±?1.4 years; mean?±?s) and ten women (age 22.4?±?2.8 years) with weight training experience of 4.5?±?2.0 years participated in this study. One-repetition maximum squats were performed on a Smith machine during each of two different intervention conditions that were counterbalanced and consisted of a free choice psych-up and a cognitive distraction. Saliva samples were obtained at the beginning of each test session and immediately after the final 1-RM attempt. No significant difference in 1-RM was identified between psyching-up (104?±?50?kg) and cognitive distraction (106?±?52?kg). Performing a 1-RM in the squat exercise significantly increased salivary cortisol concentrations during both conditions (P <?0.05). There was no significant difference in salivary cortisol responses between conditions. These results suggest that psyching-up does not increase 1-RM performance during the squat exercise in strength-trained individuals.     

Radial and tibial bone indices in athletes participating in different endurance sports: a pQCT study†

Low magnitude bone-loading sports may benefit bone structure and strength in the exercised limbs. This study compared peripheral quantitative computed tomography measures of radial and tibial diaphyseal strength (strength–strain index, SSI), structure (total area (ToA) and cortical area (CoA), density (CoD) and thickness (CT), and circumferences), muscle cross-sectional area (MCSA) and strength (one-repetition maximum, 1-RM) in male endurance athletes taking part in (i) non-weight-bearing and non-impact sports: swimmers (SWIM, n?=?13) and road cyclists (RC, n?=?10), (ii) non-weight-bearing, impact sport: mountain bikers (MB, n?=?10), (iii) weight bearing and impact sport: runners (RUN, n?=?9). All athlete groups were also compared to sedentary controls (CON, n?=?10). Arm MCSA, 1-RM and radial bone size and strength tended to be greater in SWIM than CON and/or RC (ToA, %difference ±?95%CI, SWIM-CON: 14.6%?±?12.7%; SWIM-RC: 12.9%?±?10.7%) but not different to MB and RUN. RUN had bigger tibial CoA than CON, SWIM and RC (CoA, RUN-CON: 12.1%?±?10.7%; RUN-SWIM: 10.9%?±?9.4%; RUN-RC: 15.8%?±?9.5%) without marked changes in tibial strength indices, lower-limb MCSA or 1-RM. Both MB and RC failed to display any difference in tibial indices, lower-limb MCSA and 1-RM compared to CON. In swimmers, the bone structure and strength of the primary exercised limbs, the arms, is greater than controls and road cyclists. Conversely, although runners experience impact and weight-bearing loading, tibial structure is greater without a substantial difference in tibial strength compared to controls and non-impact sports. Failure to observe a difference in tibial indices in MB and RC compared to controls is unexpected.     

Downhill walking training with and without exercise-induced muscle damage similarly increase knee extensor strength

This study examined whether avoiding or experiencing exercise-induced muscle damage (EIMD) influences strength gain after downhill walking training. Healthy young males performed treadmill downhill walking (gradient: ?28%, velocity: 5 km · h^?1 and load: 10% of body mass) 1 session per week for four weeks using either a ramp-up protocol (n = 16), where exercise duration was gradually increased from 10 to 30, 50 and 70 min over four sessions, or a constant protocol (n = 14), where exercise duration was 40 min for all four sessions. Indirect markers of EIMD were measured throughout the training period. Maximal knee extension torque in eccentric (?1.05 rad·s^?1), isometric and concentric (1.05 rad·s^?1) conditions were measured at pre- and post-training. The ramp-up group showed no indications of EIMD throughout the training period (e.g., plasma creatine kinase (CK) activity: always <185 U · L^?1) while EIMD was evident after the first session in the constant group (CK: peak 485 U · L^?1). Both groups significantly increased maximal knee extension torque in all conditions with greater gains in eccentric (ramp-up: +19%, constant: +21%) than isometric (+16%, +15%) and concentric (+12%, +10%) strength without any significant group-difference. The current results suggest that EIMD can be avoided by the ramp-up protocol and is not a major determinant of training-induced strength gain.     

The relationship between muscle cross-sectional area and strength in various isokinetic movements among soccer players

Abstract

The aim of the present study was to examine the relationships between muscle cross-sectional area (CSA) and muscular strength in terms of knee extension and flexion, hip extension and flexion, and hip abduction and adduction among well-trained soccer players. Fourteen university soccer players participated in the study, who had previously been divided into two groups based on ability (Group A: above-average ability; Group B: average ability). Maximal isokinetic and concentric muscular strength was measured in knee extension/flexion, hip extension/flexion and hip abduction/adduction using an isokinetic dynamometer at 1.57 and 4.19 rad·s^?1 (3.14 rad·s^?1) in both the dominant and non-dominant leg. The CSAs of the thigh, gluteus muscles and iliopsoas muscles were calculated based on magnetic resonance imaging. There was no significant difference between the two groups in muscle CSA and isokinetic strength. Although there were some statistically significant differences between the dominant and non-dominant leg in terms of CSA and strength (P<0.05–0.01), these were small and negligible. Apart from a non-significant relationship between the CSAs of the adductor muscles and hip adductor strength (r<0.26, n.s.), the CSA of the other muscle groups correlated with maximal isokinetic strength (r=0.38–0.64, P<0.05). These results suggest that no difference in muscle characteristics (in terms of muscle CSA and strength) was apparent among well-trained soccer players, even between the dominant and non-dominant leg. There is also a case that the anatomical function of a single (or group of) muscle(s) may not be reflected by the strength—CSA relationship depending on the movements (such as hip adduction-adductor muscle CSA). Thus, further studies are required to develop methods to assess neuromuscular function in relation to muscle morphology among soccer players.     

The modulation of corticospinal excitability and inhibition following acute resistance exercise in males and females

Objective: The acute responses to resistance training (RT) between males and females are poorly understood, especially from a neural perspective. Therefore, we aimed to compare the corticospinal and intracortical responses during fatigue and recovery following RT.

Methods: Twenty-two participants (12M, 10F) completed one-session of RT (3?×?12 repetition maximum) unilateral leg extensions with 60?s recovery. Single- and paired-pulse transcranial magnetic stimulation measured changes in the motor-evoked potential (MEP), corticospinal silent period (CSP), CSP/MEP ratio, and intracortical facilitation/inhibition (ICF, SICI). The maximal compound wave (M_MAX) measured peripheral excitability of the rectus femoris (RF) and maximal voluntary isometric contraction (MVIC) neuromuscular function of the leg extensors. Measures were taken immediately post, 30?min, 1 and 6?h post-training.

Results: A significantly greater increase in MEP/M_MAX ratio (p?=?.005) was observed for females immediately post-training compared to males. While no sex differences in MEP/M_MAX ratio was observed at 30?min and 1?h post-training, a greater MEP/M_MAX ratio for males was observed at 30?min (p?p?=?.003). CSP trended to decrease for males compared to females immediately post-training (d?=?1.93). MVIC was decreased post-training for males; 14.22% and females; 14.16% (P?MAX reduced at 30?min for both groups (P?P?>?.05).

Conclusion: The net output of corticospinal excitability is similar between males and females during fatigue. However, the mechanism in which this is modulated (increased MEP, decreased CSP) appears to be sex-specific.     

Effects of vibration and exercise training on bone mineral density and muscle strength in post-menopausal women

Abstract

The purpose of this study was to compare the effects of a specific vibration programme with those of combined aerobic and resistance exercise training on bone mineral density (BMD), body composition, and muscular strength in post-menopausal women, over a period of 6 months. Thirty-two healthy, inactive post-menopausal women aged 46–62 years were divided into exercise (n = 10), vibration (n = 13), and control (n = 9) groups. The exercise group participated in a supervised programme of strength training at 70% of one-repetition maximum (1-RM) 2 days a week, and aerobic exercise at 70–85% of maximum heart rate one day a week. The vibration group performed vibration training 3 days a week (9 sets×45–80 s per session, 35–40 Hz, peak-to-peak amplitude of vertical vibration = 1.5 mm) on a vibration platform (NemesTM LCB, Bosco System). The BMD of the lumbar spine (L2–L4) was assessed using dual-energy X-ray absorptiometry, and muscle strength with the 1-RM method at baseline and after 6 months of intervention. The BMD of L2–L4 increased in the exercise group (P < 0.05), remained steady in the vibration group, and decreased in the control group (P < 0.05). Muscular strength of leg-extension and leg-curl exercise improved by 28% and 25.5% (P < 0.01) in the exercise group and by 13% (P < 0.01) and 20.5% (P < 0.001) in the vibration group, respectively. The results indicate that conventional training contributed to the increase in BMD of L2–L4, while the vibration programme helped to maintain BMD in post-menopausal women. Both training programmes were efficient in improving muscle strength.     

Effects of drop sets with resistance training on increases in muscle CSA,strength, and endurance: a pilot study

To investigate the effects of a single high-load (80% of one repetition maximum [1RM]) set with additional drop sets descending to a low-load (30% 1RM) without recovery intervals on muscle strength, endurance, and size in untrained young men. Nine untrained young men performed dumbbell curls to concentric failure 2–3 days per week for 8 weeks. Each arm was randomly assigned to one of the following three conditions: 3 sets of high-load (HL, 80% 1RM) resistance exercise, 3 sets of low-load [LL, 30% 1RM] resistance exercise, and a single high-load (SDS) set with additional drop sets descending to a low-load. The mean training time per session, including recovery intervals, was lowest in the SDS condition. Elbow flexor muscle cross-sectional area (CSA) increased similarly in all three conditions. Maximum isometric and 1RM strength of the elbow flexors increased from pre to post only in the HL and SDS conditions. Muscular endurance measured by maximum repetitions at 30% 1RM increased only in the LL and SDS conditions. A SDS resistance training program can simultaneously increase muscle CSA, strength, and endurance in untrained young men, even with lower training time compared to typical resistance exercise protocols using only high- or low-loads.     

Strength training: Isometric training at a range of joint angles versus dynamic training

Strength training with isometric contractions produces large but highly angle-specific adaptations. To contrast the contractile mode of isometric versus dynamic training, but diminish the strong angle specificity effect, we compared the strength gains produced by isometric training at four joint angles with conventional dynamic training. Thirty-three recreationally active healthy males aged 18?–?30 years completed 9 weeks of strength training of the quadriceps muscle group three times per week. An intra-individual design was adopted: one leg performed purely isometric training at each of four joint angles (isometrically trained leg); the other leg performed conventional dynamic training, lifting and lowering (dynamically trained leg). Both legs trained at similar relative loads for the same duration. The quadriceps strength of each leg was measured isometrically (at four angles) and isokinetically (at three velocities) pre and post training. After 9 weeks of training, the increase in isokinetic strength was similar in both legs (pooled data from three velocities: dynamically trained leg, 10.7%; isometrically trained leg, 10.5%). Isometric strength increases were significantly greater for the isometrically trained leg (pooled data from four angles: dynamically trained leg, 13.1%; isometrically trained leg, 18.0%). This may have been due to the greater absolute torque involved with isometric training or a residual angle specificity effect despite the isometric training being divided over four angles.     

Effects of movement velocity and training frequency of resistance exercise on functional performance in older adults: a randomised controlled trial

Objectives: To investigate the effects that high-velocity, low-load (HVLL) and low-velocity, high-load (LVHL) resistance exercise, performed once or twice-weekly, have on indices of functional performance (primary outcome), maximal strength, and body composition (secondary outcomes) in older adults.

Methods: In a randomised, controlled, multi-armed, parallel design, 54 moderately-highly active, but resistance exercise naïve older adults (aged 60–79 years), attended baseline and post-10-week intervention assessment sessions. Physical and functional assessments were completed, and predicted one-repetition maximums (1-RM) were obtained for eight exercises. Participants were then randomised into one of five conditions: HVLL once-weekly (HVLL1: n?=?11) or twice-weekly (HVLL2: n?=?11), LVHL once-weekly (LVHL1: n?=?10) or twice-weekly (LVHL2: n?=?11), no-exercise control condition (CON: n?=?11). The HVLL conditions completed 3 sets of 14 repetitions at 40% 1-RM and the LVHL conditions, 3 sets of 7 repetitions at 80% 1-RM. In total, 50 participants completed all testing and were included in analyses.

Results: Only LVHL2 improved 30-sec chair stand performance (p?=?.035; g?=?0.89), arm curls (p?=?.011; g?=?1.65) and grip-strength (p?=?.015; g?=?0.34) compared to CON. LVHL2 improved maximal strength compared to CON for 7/8 exercises (p?p?Conclusion: Possibly due to the lower intensity nature of the HVLL conditions, LVHL, twice-weekly was most beneficial for improving functional performance and strength in moderately-highly active older adults. Therefore, we recommend that exercise professionals ensure resistance exercise sessions have sufficient intensity of effort and volume, in order to maximise functional performance and strength gains in older adults.     

Creatine co-ingestion with carbohydrate or cinnamon extract provides no added benefit to anaerobic performance

The insulin response following carbohydrate ingestion enhances creatine transport into muscle. Cinnamon extract is promoted to have insulin-like effects, therefore this study examined if creatine co-ingestion with carbohydrates or cinnamon extract improved anaerobic capacity, muscular strength, and muscular endurance. Active young males (n?=?25; 23.7?±?2.5?y) were stratified into 3 groups: (1) creatine only (CRE); (2) creatine+ 70?g carbohydrate (CHO); or (3) creatine+ 500?mg cinnamon extract (CIN), based on anaerobic capacity (peak power·kg^?1) and muscular strength at baseline. Three weeks of supplementation consisted of a 5?d loading phase (20?g/d) and a 16?d maintenance phase (5?g/d). Pre- and post-supplementation measures included a 30-s Wingate and a 30-s maximal running test (on a self-propelled treadmill) for anaerobic capacity. Muscular strength was measured as the one-repetition maximum 1-RM for chest, back, quadriceps, hamstrings, and leg press. Additional sets of the number of repetitions performed at 60% 1-RM until fatigue measured muscular endurance. All three groups significantly improved Wingate relative peak power (CRE: 15.4% P?=?.004; CHO: 14.6% P?=?.004; CIN: 15.7%, P?=?.003), and muscular strength for chest (CRE: 6.6% P?P?P?P?P?P?P?=?.013; CHO: 10.0% P?=?.007; CIN: 17.3% P?P?=?.021) and CIN (15.5%, P?相似文献   

Non-linear resistance training reduces inflammatory biomarkers in persons living with HIV: A randomized controlled trial

The purpose of this study is to analyse the effect of 12 weeks of non-linear resistance training (NLRT) on anthropometry, muscle strength and inflammatory biomarkers in persons infected with human immunodeficiency virus (PIHIV). Thirty previously sedentary PIHIVs were randomized into the NLRT (n?=?15) and control (CON, n?=?15) groups. NLRT group were submitted to 12 weeks of training, whereas the CON group maintained their daily habits. At baseline and after 12 weeks, both groups underwent anthropometric evaluations and blood sampling for the analysis of inflammatory biomarkers. Analysis of covariance using preintervention values as covariate was performed to determine the effects of exercise on anthropometry, muscle strength, cytokines levels and T cells. Significance was set at p?p?p p?=?.009), blood levels of interleukin (IL)-1β (p?=?.029), IL-6 (p?=?.005), IL-8 (p?=?.010), and tumour necrosis factor (TNF)-α (p?=?.001) and an increase in muscle strength (p?p?=?.030) and CD4⁺ (p?=?.004) and CD8⁺ (p?相似文献