Aerobic exercise performance is seriously compromised in the heat. Possibly, a high skin temperature causes a rating of perceived exertion (RPE)-mediated decrease in exercise intensity. The purpose of this study was to determine the effect of skin temperature on power output during a 7.5-km cycling time trial. Thirteen well-trained male ...

This study examined the effects of prior heavy-intensity exercise on the adjustment of pulmonary oxygen uptake (VO(2p)) and muscle deoxygenation Δ[HHb] during the transition to subsequent heavy-intensity cycling (CE) or knee-extension (KE) exercise. Nine young adults (aged 24 ± 5 years) performed 4 repetitions of repeated bouts of heavy-intensity exercise separated by ...

Fatty acids (FA) as fuel for energy utilization during exercise originate from different sources: FA transported in the circulation either bound to albumin or as triacylglycerol (TG) carried by very low density lipoproteins (VLDL) and FA from lipolysis of muscle TG stores (IMTG). Despite a high rate of energy expenditure ...

This study characterized the profile of near-infrared spectroscopy (NIRS)-derived muscle deoxygenation (Δ[HHb]) and the tissue oxygenation index (TOI) as a function of absolute (PO(ABS)) and normalized power output (%PO) or oxygen consumption (%VO(2)) during incremental cycling exercise. Eight men (24 ± 5 year) each performed two fatigue-limited ramp incremental cycling tests (20 W min(-1)), during ...

Stroke volume augmentation during exercise is limited in COPD patients because of decreased preload from dynamic hyperinflation (DH). We hypothesized that O2 pulse and pulse pressure (PP) improve following LVRS and the magnitude of improvement correlates with reduction in DH.We compared 16 emphysema patients undergoing LVRS with 6 emphysema patients ...

Athletes such as skaters and skiers inhale large volumes of cold air during exercise and shift from nasal to mouth breathing. Endurance athletes, like cross-country skiers, perform at 80% or more of their maximal oxygen consumption and have minute ventilations in excess of 100 l/min. Cold air is always dry, ...

To date, no studies have examined whether there are either sex- or ovarian hormone-related alterations in arterial baroreflex resetting and function during dynamic exercise. Thus, we studied 16 young men and 18 young women at rest and during leg cycling at 50% heart rate (HR) reserve. In addition, 10 women ...

We explored whether maternal exercise during pregnancy moderates the effect of fetal breathing movements on fetal cardiac autonomic control assessed by metrics of heart rate (HR) and heart rate variability (HRV). Thirty women were assigned to Exercise or Control group (n=15/group) based on the modifiable physical activity questionnaire (MPAQ). Magnetocardiograms ...

l-Arginine (L-arg) is an amino acid precursor to nitric oxide (NO). Dietary supplements containing L-arg have been marketed with the purpose of increasing vasodilation, thereby elevating blood flow to the exercising muscle and enhancing the metabolic response to exercise. Our goal was to identify the acute effect of L-arg supplementation ...

BACKGROUND: The prevalence of exercise-induced gastrointestinal (GI) symptoms has been reported up to 70%. The pathophysiology largely remains unknown. AIM: To review the physiological and pathophysiological changes of the GI-tract during physical exercise and the management of the most common gastrointestinal symptoms. METHODS: Search of the literature published in the ...

OBJECTIVES: This study investigated the influence of carbohydrate supplementation on skill performance throughout exercise that replicates soccer match-play. DESIGN: Experimentation was conducted in a randomised, double-blind and cross-over study design. METHODS: After familiarization, 15 professional academy soccer players completed a soccer match simulation incorporating passing, dribbling and shooting on two ...

A key, but less understood, function of the cardiovascular system is to exchange heat between the internal body organs and the skin to maintain internal temperature within a narrow range in a variety of conditions that produce vast changes in external (exogenous) and/or internal (endogenous) thermal loads. Heat transfer via ...

AIMS: To investigate the use of atropine to achieve target heart rate (THR) and rate pressure product (RPP) during supine bicycle exercise stress echocardiography (SBESE) to increase the number of diagnostic stress tests. METHODS AND RESULTS: Forty-four patients that were unable to achieve THR or RPP during SBESE performed to ...

The effect of inter-repetition rest (IRR) periods on power output during performance of multiple sets of power cleans is unknown. It is possible that IRR periods may attenuate the decrease in power output commonly observed within multiple sets. This may be of benefit for maximizing improvements in power with training. ...

Regulation of subcutaneous adipose tissue blood flow (ATBF) remains poorly elucidated in humans, especially during exercise. In the present study we tested the role of adenosine in the regulation ATBF adjacent to active and inactive thigh muscles during intermittent isometric knee-extension exercise (1 s contraction followed by 2 s rest ...

This study aimed to analyze elite team handball physical and physiological demands during match play. Time-motion (N = 30) and heart rate (HR; N = 60) analyses were performed throughout ten official matches. The defined locomotor categories were: standing still, walking, jogging, fast running, sprinting, backwards movement, sideways medium-intensity movement ...

Effects of deception and expected duration on the rating of perceived exertion (RPE), affect, and heart rate (HR) were examined during treadmill (n = 12) and cycling (n = 8) exercise. Participants completed three conditions: (1) 20 MIN-exercise for 20 min, stop after 20 min; (2) 10 MIN-exercise for 10 min, in 10th min be told to exercise for ...

This study investigated changes incurred in cutaneous skin blood flux (SKBF) in the superficial veins of the lower limb by upper limb exercise training in the form of arm-cranking in 14 healthy participants over the age of 50 years. Changes in cutaneous microvascular function of the lower leg were assessed ...

Regular exercise improves the age-related decline in cerebral blood flow (CBF) and is associated with improved cognitive function; however, less is known about the direct relationship between CBF and cognitive function. We examined the influence of healthy aging on the capability of acute exercise to improve cognition, and whether exercise-induced ...

Postnatal hypoxia is a main cause of neuronal damage in newborn. However, our understanding of the possible preventive or therapeutic methods to reduce the harmful effects of hypoxia is still primary. Pregnant rats were provided with running wheels during their pregnancy. On PND4 (postnatal day 4)to PND8, the rat pups ...

Munguía-Izquierdo D, Santalla A, Legaz-Arrese A. Evaluation of a wearable body monitoring device during treadmill walking and jogging in patients with fibromyalgia syndrome. To evaluate the reliability and validity of a body monitoring device against measures obtained from indirect calorimetry (IC) in patients with fibromyalgia syndrome (FMS) during various incremental ...

To examine the acute cardiorespiratory and metabolic responses in competitive cross-country skiers with disabilities. Cross-sectional comparisons using a select group of Canadian athletes training for the Vancouver 2010 Paralympic Winter Games. Canmore Nordic Centre Provincial Park, Canmore, Alberta. Nine competitive cross-country skiers (4 with visual impairment, 1 with traumatic brain ...

The purpose of this study was to determine whether reflex sweating during isometric handgrip exercise (IHG) in the heat was due to a priming effect in the sweat glands or an increase in skin temperature. Ten male subjects completed four trials where they performed IHG for three minutes at 40% ...

The aims of this study were to establish mechanical demands of kettlebell swing exercise, and provide context by comparing them to mechanical demands of back squat and jump squat exercise. Sixteen men performed two sets of 10 swings with 16, 24, and 32 kg, two back squats with 20, 40, ...

Obesity, particularly severe central obesity, affects respiratory physiology both at rest and during exercise. Reductions in expiratory reserve volume, functional residual capacity, respiratory system compliance, and impaired respiratory system mechanics produce a restrictive ventilatory defect. Low functional residual capacity and reductions in expiratory reserve volume increase the risk of expiratory ...

Utilization of carbohydrate in the form of intramuscular glycogen stores and glucose delivered from plasma becomes an increasingly important energy substrate to the working muscle with increasing exercise intensity. This review gives an update on the molecular signals by which glucose transport is increased in the contracting muscle followed by ...

Purpose:To determine whether nifedipine, an L-type calcium channel blocker, alters choroidal blood flow (ChBF) regulation during isometric exercise in healthy subjects.Methods:The study was carried out in a randomized, placebo-controlled, double-masked, two-way crossover design. 15 healthy male subjects were randomized to receive either placebo or nifedipine on two different study days. ...

Limited information is available regarding the effects of mild dehydration on cognitive function. Therefore, mild dehydration was produced by intermittent moderate exercise without hyperthermia and its effects on cognitive function of women were investigated. Twenty-five females (age 23.0 ± 0.6 y) participated in three 8-h, placebo-controlled experiments involving a different ...

Dynamic hyperinflation (DH) during exercise occurs in most but not all patients with advanced COPD. It is not known whether the presence or absence of DH has implications for dyspnoea and exercise tolerance. Therefore, we compared detailed ventilatory and sensory responses to exercise in hyperinflators and non-hyperinflators with moderate to ...

We tested the hypothesis that preventing the poikilocapnic response to high intensity exercise would increase the ventilatory response to exercise. We measured ventilatory variables in 10 healthy men during incremental cycling with and without inspired CO(2) (randomised order). Inspired CO(2) elevated resting ventilation (V˙(E)), tidal volume (V(T)), [Formula: see text] ...

The accuracy of the American College of Sports Medicine (ACSM) equations for producing predicted values of heart rate reserve (HRR) and oxygen uptake reserve [Formula: see text] and consequently, target energy expenditure (EE) during exercise are yet to be established. This study investigated whether speeds defined by the ACSM metabolic ...

Our aim was to test the hypothesis that apnea-induced hemodynamic responses during dynamic exercise in humans differ between those who show strong bradycardia and those who show only mild bradycardia. After evaluating apnea-induced changes in heart rate (HR) during dynamic exercise, 23 healthy subjects were selected and divided into a ...

Kemmler, W, von Stengel, S, Schwarz, J, and Mayhew, JL. Effect of whole-body electromyostimulation on energy expenditure during exercise. J Strength Cond Res 26(1): 240-245, 2012-The application of whole-body electromyostimulation (WB-EMS) in the area of fat reduction and body shaping has become more popular recently. Indeed, some studies prove positive ...

Saddle height is one of the most researched areas of bike fit. The current accepted method for adjusting saddle height involves use of a goniometer to adjust saddle height so that a knee angle between 25° and 35° is obtained. This measurement is taken while the cyclist maintains a static ...

In this study, we observed the variations on physiological and perceptual variables during a self-paced 10,000-m race walking event with the aim to trace a preliminary performance profile of the distance. On fourteen male athletes, heart rate was monitored continuously throughout the event. The rating of perceived exertion was collected ...

Physical activity has an impact on several endocrine functions. During exercise certain endocrine adjustments are required to maintain the homeostasis. It is well known that depending on the intensity and duration, exercise stimulates the release of the hormone prolactin (PRL). After the cessation of acute exercise this effect persist and ...

ABSTRACT: BACKGROUND: Carbohydrates (CHOs), branched-chain amino acids (BCAAs) and caffeine are known to improve running performance. However, no information is available on the effects of a combination of these ingredients on performance and neuromuscular function during running. METHODS: The present study was designed as a randomized double-blind cross-over placebo-controlled trial. ...

The enhancement of fat oxidation during exercise is an aim for both recreational exercising individuals and endurance athletes. Nutritional status may explain a large part of the variation in maximal rates of fat oxidation during exercise. This review reveals novel insights into nutritional manipulation of substrate selection during exercise, explaining ...

AimInitial power output declines significantly during exercise in hot conditions on attaining a rapid increase in skin temperature when exercise commences. It is unclear whether this initial reduced power is mediated consciously, through thermal perceptual cues, or is a subconscious process. The authors tested the hypothesis that improved thermal perception ...

INTRODUCTION: Although it has been reported that the work of breathing may be higher in women, inconsistencies among studies leaves this important question unresolved. Also, the association between the oxygen cost of breathing and rating of perceived breathlessness (RPB) during exercise has not been examined between women and men. PURPOSE: ...

Oxygen (O(2)) extraction is impaired in exercising skeletal muscle of humans with mutations of mitochondrial DNA (mtDNA), but the muscle hemodynamic response to exercise has never been directly investigated. This study sought to examine the extent to which human skeletal muscle perfusion can increase without reductions in blood oxygenation and ...

Metabolites of the cytochrome P450 (CYP) pathway may contribute to vasodilation of the vasculature. However, it is not known whether exercise affects their circulating concentrations. The authors determined effects of exercise intensity and duration on plasma concentrations of epoxy and dihydroxy metabolites of arachidonic acid. Their goal was to delineate ...

The aim of this prospective cohort study was to identify which blood pressure measurement during exercise is the best predictor of future hypertension. Further we aimed to create a risk chart to facilitate the evaluation of blood pressure reaction during exercise testing. A number (n=1047) of exercise tests by bicycle ...

The purpose of the present study was to investigate the effect of glycemic index (GI) and fructose content in lunch on substrate utilization during subsequent brisk walking. Ten healthy young males completed 3 main trials in a counterbalanced crossover design. They completed 60 min of brisk walking at approximately 50% maximal ...

This paper describes a new mathematical approach for the analysis of HR (heart rate) and BL (blood lactate) curves during incremental exercise testing using a HR/BL curve and its derivatives, taking into account the native shape of all curves, without any linear approximation. Using this approach the results indicate the ...

Exposure to cold environments affects human performance and physiological function. Major medical organizations recommend rectal temperature (TREC) to evaluate core body temperature (TcORE) during exercise in the cold; however, other field expedient devices claim to measure TCORE. The purpose of this study was to determine if field expedient devices provide ...

The aims of this study were to estimate the energy expenditure (EE) and the intensity of physical activity (PA) during a competitive simulation of Latin American dancing and to evaluate the differences in PA and EE values between the sexes, between different dance types, and between the various phases of ...

It has been demonstrated that the local neuromuscular response during high intensity exercise has a strong relationship with endurance markers. However, a diminished neuromuscular response has been reported for the operated leg in athletes having undergone anterior cruciate ligament reconstruction (ACLR). The purpose of the present study was to examine ...

This study compared the metabolic and performance effects of riding front-only suspension (FS) and front-and-rear suspension (FRS) mountain bicycles on an off-road course that simulated competitive cross-country race conditions (>105 min in duration, with ∼70% of time spent riding uphill). Seven competitive mountain bikers (73.8 ± 7.6 kg; 61.0 ± ...

To compare the effect of inter-set cooling and no cooling during resistance exercise (RE) on the total repetitions and select muscle damage biomarker responses. Sixteen healthy men volunteered to participate in this study and were randomly assigned to Cooling (n = 8) or Control (n = 8) groups. They performed ...