Does intensity really matter regarding aerobic exercise reductions in wave reflection and central hemodynamics? Commentary on "The effect of acute aerobic exercise on central arterial stiffness,wave reflections,and hemodynamics in adults with diabetes: A randomized cross-over design"by Way et al.

We read with great interest the study by Way et al.1 pub-lished in this journal, which described and compared the acute changes in central arterial stiffness (A...     

Changes in selected cardiorespiratory responses to exercise and in body composition following a 12‐week aerobic dance programme

Cardiorespiratory and body composition changes were evaluated in 25 sedentary females, aged 18 to 30 years, following 12 weeks of aerobic dance training (3 days a week, 45 min a session). Fifteen subjects, from the same population, comprised a control group: they maintained their normal activity and dietary habits over the course of the study. Analysis of variance of the values for selected cardiorespiratory responses revealed that the aerobic dance programme produced training effects in the experimental group. These training effects were indicated by significant improvements in O₂ pulse, V _E, heart rate and perceived exertion during submaximal exercise. Significant improvements were also noted in VO₂ max, maximal O₂pulse, V _E max, maximal heart rate and maximal running time on the treadmill. Additionally, increases in lean body mass and body density, together with decreases in percentage body fat and the sum of four skinfold thicknesses were found to be significant for the experimental group. No significant improvements in any of these variables were found for the control group. It was concluded that this 12‐week aerobic dance programme was successful in promoting beneficial changes in cardiorespiratory fitness and body composition.     

Impacts of exercise intervention on various diseases in rats

Background:Exercise is considered as an important intervention for treatment and prevention of several diseases,such as osteoarthritis,obesity,hypertension,and Alzheimer's disease.This review summarizes decadal exercise intervention studies with various rat models across 6 major systems to provide a better understanding of the mechanisms behind the effects that exercise brought.Methods:PubMed was utilized as the data source.To collect research articles,we used the following terms to create the search:(exercise[Title]OR physical activity[Title]OR training[Title])AND(rats[Title/Abstract]OR rat[Title/Abstract]OR rattus[Title/Abstract]).To best cover targeted studies,publication dates were limited to"within 11 years."The exercise intervention methods used for different diseases were sorted according to the mode,frequency,and intensity of exercise.Results:The collected articles were categorized into studies related to 6 systems or disease types:motor system(17 articles),metabolic system(110 articles),cardiocerebral vascular system(171 articles),nervous system(71 articles),urinary system(2 articles),and cancer(21 articles).Our review found that,for different diseases,exercise intervention mostly had a positive effect.However,the most powerful effect was achieved by using a specific mode of exercise that addressed the characteristics of the disease.Conclusion:As a model animal,rats not only provide a convenient resource for studying human diseases but also provide the possibility for exploring the molecular mechanisms of exercise intervention on diseases.This review also aims to provide exercise intervention frameworks and optimal exercise dose recommendations for further human exercise intervention research.     

Inter-individual differences in the responses to aerobic exercise in Alzheimer’s disease: Findings from the FIT-AD trial

Background:Despite the strong evidence of aerobic exercise as a disease-modifying treatment for Alzheimer’s disease(AD)in animal models,its effects on cognition are inconsistent in human studies.A major contributor to these findings is inter-individual differences in the responses to aerobic exercise,which was well documented in the general population but not in those with AD.The purpose of this study was to examine inter-individual differences in aerobic fitness and cognitive responses to a 6-month aerobic exercise intervention in community-dwelling older adults with mild-to-moderate dementia due to AD.Methods:This study was a secondary analysis of the Effects of Aerobic Exercise for Treating Alzheimer’s Disease(FIT-AD)trial data.Aerobic fitness was measured by the shuttle walk test(SWT),the 6-min walk test(6MWT),and the maximal oxygen consumption(VO2max)test,and cognition by the AD Assessment Scale-Cognition(ADAS-Cog).Inter-individual differences were calculated as the differences in the standard deviation of 6-month change(SDR)in the SWT,6MWT,VO2max,and ADAS-Cog between the intervention and control groups.Results:Seventy-eight participants were included in this study(77.4±6.3 years old,mean±SD;15.7±2.8 years of education;41%were female).VO2max was available for 26 participants(77.7±7.1 years old;14.8±2.6 years of education;35%were female).The SDR was 37.0,121.1,1.7,and 2.3 for SWT,6MWT,VO2max,and ADAS-Cog,respectively.Conclusion:There are true inter-individual differences in aerobic fitness and cognitive responses to aerobic exercise in older adults with mild-tomoderate dementia due to AD.These inter-individual differences likely underline the inconsistent cognitive benefits in human studies.     

The effects of 15 min and 30 min of exercise on affective responses both during and after exercise

Although much research has examined the relationship between exercise and affect, few studies have considered the effects of exercise bouts of different durations and few researchers have questioned the longer term effects that might be associated with acute exercise. The aim of this study was to compare the effects of the standard health recommended exercise duration of 30?min with a shorter (15?min) bout of exercise upon individuals' affect scores both during and after exercise. Twenty-three (mean age 22.4 years) physically active participants engaged in two counterbalanced cycle ergometer exercise conditions for 15?min (short bout) and 30?min (moderate bout). The participants completed the Subjective Exercise Experience Scale before, during, 5?min, 30 mins, 1?h and 2?h after both exercise conditions. A series of 2 × 6 within-participant repeated-measures analyses of variance for positive well-being (P?<0.01), psychological distress (P?<0.01) and fatigue (P?<0.01) scores revealed significant time main effects, with improved scores over time. No significant differences were noted between the 15-min and 30-min exercise bouts. These results indicate that positive affective responses are experienced by exercisers after relatively short bouts of acute exercise and these effects can still be evident some time later.     

Land-walking vs.water-walking interventions in older adults:Effects on aerobic fitness

Background:Low cardiorespiratory fitness is an independent predictor of all-cause and cardiovascular mortality,and interventions that increase fitness reduce risk.Water-walking decreases musculoskeletal impact and risk of falls in older individuals,but it is unclear whether water-walking improves aerobic fitness in the same way as weight-dependent land-walking.This randomized controlled trial involved 3 intervention groups—a no-exercise control group(CG),a land-walking(LW)group,and a water-walking(WW)group—to investigate the comparative impacts of LWandWWto CG on fitness.Methods:Both exercise groups attended individually tailored,center-based,intensity-matched 3×weekly sessions for 24 weeks,which progressed to 150 min of exercise per week.This was followed by a 24-week no-intervention period.Maximal graded exercise tests were performed on a treadmill at Weeks 0,24,and 48.Results:Maximal oxygen uptake increased from Week 0 to Week 24 in both exercise groups(0.57±0.62 mL/kg/min,0.03±0.04 L/min for LW;0.93±0.75 mL/kg/min,0.06±0.06 L/min for WW,mean±SE)compared to the CG(-1.75±0.78 mL/kg/min,-0.16±0.05 L/min)(group×time,p<0.05).Time to exhaustion increased significantly following LW only(123.4±25.5 s),which was significantly greater(p=0.001)than the CG(24.3±18.5 s).By Week 48,the training-induced adaptations in the exercise groups returned to near baseline levels.Conclusion:Our study supports current physical-activity recommendations that 150 min/week of moderate-intensity exercise produces improvements in fitness in previously sedentary older individuals.Also,LW andWW elicit similar improvements in fitness if conducted at the same relative intensities.Exercise-na?ve older individuals can benefit from the lower impact forces and decreased risk of falls associated withWWwithout compromising improvements in cardiorespiratory fitness.     

Hard bodies: exploring historical and cultural factors in disabled people’s participation in exercise; applying critical disability theory

Abstract

The popularity of the Paralympics co-exists with persistent exclusion of disabled youth and adults in community sport and recreation programmes around the world. This study explored the experiences of disabled people in sport, fitness and dance, drawing upon a range of participants’ perspectives from Paralympic athletes and professional dancers, to those who’d never engaged in physical activities. We asked participants about the range of psycho-social factors that intervene between a disabled person and a workable, enjoyable fitness regimen. Insights emerged into factors that encourage enjoyable physical movement for some, and factors that discourage or prohibit this for others. Analytic tools of Critical Disability Theory were applied to penetrate stereotyped conceptualizations of disabled people, taking a long view into the history of disability discrimination and exclusion. An example is the concept and (English) word, ‘fitness’ used during the Eugenics Movement to dismiss the worth of disabled people. Along with other marginalized populations, the ‘unfit’ were systematically targeted with elimination. We addressed these archaic attitudes, in concert with the present era’s intrusions of architectural, programmatic and attitudinal barriers, which may become internalized as resistance to physical activities. Participants offered strategies to support others in the world of movement, along with encouragement to Disability Studies scholars to expand research in this arena.     

Do aerobic characteristics explain isometric exercise-induced neuromuscular fatigue and recovery in upper and lower limbs?

This study investigated the relationships between aerobic characteristics and (i) neuromuscular fatigue induced by 2-min sustained isometric maximal voluntary contractions (MVC) and (ii) subsequent recovery, in the upper and lower limbs. In a pseudo-randomized order, eleven healthy males completed four sessions on different days: maximal incremental cycling test (100 W + 40 W every 2 min); maximal arm-cranking test (50 W + 20 W every 2 min); and 2-min sustained isometric MVCs of the knee extensors (KE) and elbow flexors (EF). Neuromuscular assessment was performed with transcranial magnetic and peripheral nerve stimulation to evaluate central and peripheral neuromuscular factors of fatigue and the subsequent recovery. Peak oxygen uptake, gas exchange threshold and the corresponding power outputs were correlated with recovery of voluntary force after the 2-min KE MVC. Regression analysis showed that power output at the gas exchange threshold alone explained 72% of the variability in ?recovery of KE voluntary force. No relationships with fatigue or recovery in EF were observed. These results suggest that participants with greater aerobic capacities experience the same amount of fatigue and faster recovery of voluntary force in KE but not EF. The potential reasons behind the relationship in KE but not EF are discussed.     

Effects of small-volume soccer and vibration training on body composition,aerobic fitness,and muscular PCr kinetics for inactive women aged 20–45

PurposeThe present study investigated the effects of 16 weeks of small-volume, small-sided soccer training soccer group (SG, n = 13) and oscillating whole-body vibration training vibration group (VG, n = 17) on body composition, aerobic fitness, and muscle PCr kinetics in healthy inactive premenopausal women in comparison with an inactive control group (CO, n = 14).MethodsTraining for SG and VG consisted of twice-weekly 15-min sessions with average heart rates (HRs) of ∼155 and 90 bpm respectively. Pre- and post-measurements of body composition (DXA), phosphocreatine (PCr) on- and off-kinetics, and HR measurements during standardised submaximal exercise were performed.ResultsAfter 16 weeks of training in SG, fat percentage was lowered (p = 0.03) by 1.7% ± 2.4% from 37.5% ± 6.9% to 35.8% ± 6.2% and the PCr decrease in the quadriceps during knee-extension ramp exercise was attenuated (4% ± 8%, p = 0.04), with no changes in VG or CO (time-group effect: p = 0.03 and p = 0.03). Submaximal exercise HR was also reduced in SG after 16 weeks of training (6% ± 5% of HR_max, p = 0.01).ConclusionShort duration soccer training for 16 weeks appears to be sufficient to induce favourable changes in body composition and indicators of aerobic fitness and muscle oxidative capacity in untrained premenopausal women.     

Acute intraocular pressure changes during isometric exercise and recovery: The influence of exercise type and intensity,and participant´s sex

ABSTRACT

We assessed the intraocular pressure (IOP) behaviour during a 1-minute period of isometric physical effort and the immediate 1-minute of recovery in the mid-thigh clean pull and squat exercises at three different intensities. Twenty physically active individuals performed the isometric mid-thigh clean pull and squat exercises at three intensities (0% [low-intensity], 25% [medium-intensity] and 50% [high-intensity] of the maximum isometric force). IOP was semi-continuously measured by rebound tonometry. There was a statistically significant effect of exercise intensity on IOP (p < 0.001, ?_p² = 0.416), observing that IOP increments were positively associated with exercise intensity. The mid-thigh clean pull and squat exercises did not demonstrate differences (p = 0.510), and also, no differences were observed between men and women (p = 0.683). The IOP changes during the isometric physical effort showed a positive linear behaviour in all conditions (r = 0.70 to 0.96). IOP returned to baseline levels after 8 seconds of recovery. Our data showed a progressive and instantaneous IOP increment during isometric exercise, which was positively associated with exercise intensity. IOP changes were independent on the type of exercise and participant´s sex. After exercise, IOP rapidly (≈ 8 seconds) returned to baseline levels.     

Acute effects of exercise and active video games on adults’ reaction time and perceived exertion

The purpose of the present study was to examine the acute effects of resting, aerobic exercise practised alone, and aerobic exercise with active video games (AVG), on complex reaction time (CRT) and the post-exercise acute rate of perceived exertion (RPE) in young healthy adults. The experimental group was composed of 92 healthy young adults, 78 males and 13 females (age M?=?21.9?±?2.7 years) who completed two sessions, A and B. In session A, participants rode 30?min on an ergometer, while in session B they exercised for 30?min on an ergometer while playing an AVG on a Wii. The control group was composed of 30 young adults, 26 males and 4 females (age M?=?21.4?±?2.9 years) who rested for 30?min. In each session, a CRT task was performed before and after exercising or resting, and post-exercise global RPE was noted. Repeated measures general linear model (GLM) and Wilcoxon tests were performed. (1) Both aerobic exercise alone and aerobic exercise combined with AVG improved CRT, while resting did not; (2) aerobic exercise combined with AVG did not improve CRT more than aerobic exercise only; and (3) RPE was lower after aerobic exercise combined with AVG compared with aerobic exercise only. In young adults, exercise produces acute benefits on CRT, and practising exercise with AVG helps to decrease RPE.     

Searle,Merleau-Ponty,Rizzolatti – three perspectives on Intentionality and action in sport

Actions in sport are intentional in character. They are directed at and are about something. This understanding of intentional action is common in continental as well as analytic philosophy. In sport philosophy, intentionality has received relatively little attention, but has more recently come on the agenda. In addition to what we can call ‘action intentionality,’ studied by philosophers like Searle, the phenomenological approach forwarded by Merleau-Ponty has opened up for a concept of ‘motor intentionality,’ which means a basic bodily attention and relatedness to the surrounding world. This conception is very relevant for the study of bodily actions as we find them in sports. However, there may be even deeper layers. The identification of mirror neurons in the brain has opened up for a type of almost ‘muscular intentionality’ whereby a simple bodily movement like grasping a cup to drink seems to be intentionally controlled and orchestrated. My goal in this paper is to discuss the relation between different levels of intentionality, such as a) ‘action intentionality’ operating at a conscious cognitive level, as for instance, when a player shoots a goal in football, b) the ‘motor intentionality’ directing the bodily movements when kicking the ball, and c) the muscular ‘mirror neuron intentionality’ of the goal keeper which is in operation when the keeper is seeing how the kicker’s foot hits the ball. How are these different layers of intentionality related and how can they give a more nuanced and integrated picture of the body–mind in action in sports?     

The effects of work – rest duration on intermittent exercise and subsequent performance

This study examined the effects of different work?–?rest durations during 40?min intermittent treadmill exercise and subsequent running performance. Eight males (mean?±?s: age 24.3?±?2.0 years, body mass 79.4?±?7.0?kg, height 1.77?±?0.05?m) undertook intermittent exercise involving repeated sprints at 120% of the speed at which maximal oxygen uptake (v-[Vdot]O_2max) was attained with passive recovery between each one. The work?–?rest ratio was constant at 1:1.5 with trials involving short (6:9?s), medium (12:18?s) or long (24:36?s) work?–?rest durations. Each trial was followed by a performance run to volitional exhaustion at 150% v-[Vdot]O_2max. After 40?min, mean exercise intensity was greater during the long (68.4?±?9.3%) than the short work?–?rest trial (54.9?±?8.1% [Vdot]O_2max; P?<?0.05). Blood lactate concentration at 10?min was higher in the long and medium than in the short work?–?rest trial (6.1?±?0.8, 5.2?±?0.9, 4.5?±?1.3?mmol?·?l^?1, respectively; P?<?0.05). The respiratory exchange ratio was consistently higher during the long than during the medium and short work?–?rest trials (P <?0.05). Plasma glucose concentration was higher in the long and medium than in the short work?–?rest trial after 40?min of exercise (5.6?±?0.1, 6.6?±?0.2 and 5.3?±?0.5?mmol?·?l^?1, respectively; P?<?0.05). No differences were observed between trials for performance time (72.7?±?14.9, 63.2?±?13.2, 57.6?±?13.5?s for the short, medium and long work?–?rest trial, respectively; P = 0.17), although a relationship between performance time and 40?min plasma glucose was observed (P?<?0.05). The results show that 40?min of intermittent exercise involving long and medium work?–?rest durations elicits greater physiological strain and carbohydrate utilization than the same amount of intermittent exercise undertaken with a short work?–?rest duration.     

The acute effects of resistance exercise on affect,anxiety, and mood – practical implications for designing resistance training programs

ABSTRACT

Research in aerobic exercise has linked the affective responses (pleasure–displeasure) experienced during exercise to future exercise participation. While this is yet to be confirmed in anaerobic activities, it can be inferred that making resistance exercise (RE) more psychologically rewarding is an important consideration. The purpose of this article is to review the acute effects of RE on affect, anxiety, and mood and to draw conclusions on how to maximize feelings of pleasure in an effort to increase rates of participation. This review provides evidence to support lower training volumes performed at low to moderate intensities (50–70% 1RM) with long inter-set rest intervals (90–150 s). Additional recommendations are provided based on physiological and theoretical support, but there is a strong need for more research on the affective experience of RE.     

Physiological comparison of intensity-controlled,isocaloric intermittent and continuous exercise†

VO2 fluctuations are argued to be an important mechanism underpinning chronic adaptations following interval training. We compared the effect of exercise modality, continuous vs. intermittent realized at a same intensity, on electrical muscular activity, muscular oxygenation and on whole body oxygen uptake. Twelve participants (24?±?5 years; VO2peak: 43?±?6?mL·?min^?1·kg^?1) performed (i) an incremental test to exhaustion to determine peak work rate (WR_peak); two randomized isocaloric exercises at 70%WRpeak; (ii) 1 bout of 30 min; (iii) 30 bouts of 1?min work intercepted with 1?min passive recovery. For electromyography, only the CON exercise showed change for the vastus lateralis root-mean-square (+6.4?±?5.1%, P?P?vs. 2.32?±?1.21?mM, respectively, for the CON and INT, P?vs. 356?±?301?sec, respectively, for the CON and INT, P?相似文献   

Can changes in resistance exercise workload influence internal load,countermovement jump performance and the endocrine response?

This study examined the influence of differing volume load and intensity (%1 repetition maximum[%1RM]) resistance exercise workouts on session rating of perceived exertion (sRPE) countermovement jump (CMJ) performance and endocrine responses. Twelve participants performed a workout comprising four exercises (bench press, back squat, deadlift and prone bench pull) in randomised order as either power (POW); 3 sets × 6 repetitions at 45%1RM × 3 min inter-set rest, strength (ST); 3 sets × 3 repetitions at 90%1RM × 3 min inter-set rest, or hypertrophy (HYP); 3 sets × 10 repetitions at 70%1RM × 1 min inter-set rest in a randomised-crossover design. CMJ performance and endocrine responses were measured immediately pre-, post-, 12, 24, 48 and 72 h post-exercise. POW sRPE (3.0 ± 1.0) was lower than ST (4.5 ± 1.0) (P = 0.01), and both were lower than HYP (8.5 ± 1.0) (P = 0.01). Duration of CMJ decrement was longer (P ≤ 0.05) for HYP (72 h) compared to POW (12 h) and ST (24 h). Testosterone concentration was greater (P ≤ 0.05) immediately post-exercise in HYP compared to POW and ST. In conclusion, less inter-set rest, greater volume load and intensity (%1RM) may increase sRPE, duration of CMJ performance decrement and testosterone responses in resistance exercise.