Fasting for 48 h induced similar glucose intolerance in both sexes despite greater perceived stress and decreased estradiol levels in females.

Purpose: The purpose of this study was to compare the effects of fasting for 48 h on the evoked insulin and glucose responses in males and females, and to explore factors such as stress and estrogen levels that might influence these responses.

Methods: Healthy, nonobese male (n = 14) and female (n = 14) subjects underwent 48-h fasting trial. Changes in glucose tolerance and insulin levels in response to the oral glucose tolerance test, subjectively perceived stress and catecholamine concentrations were measured in all participants.

Age-Related Difference in Cognitive Performance under Severe Whole-Body Hyperthermia Parallels Cortisol and Physical Strain Responses.

: To date, understanding age-related changes in cognitive processes during heat exposure still needs to be better-understood. Thus, the main aim of the current study was to evaluate the effects of whole-body hyperthermia (WBH), i.e.

Age-related differences in the neuromuscular performance of fatigue-provoking exercise under severe whole-body hyperthermia conditions.

Purpose: The purpose of this study was to determine if aging would lead to greater decline in neuromuscular function during a fatiguing task under severe whole-body hyperthermia conditions.

Methods: Twelve young (aged 19-21 years) and 11 older (aged 65-80 years) males were enrolled in the study, which comprised a randomized control trial under a thermoneutral condition at an ambient temperature of 23°C (CON) and an experimental trial with passive lower body heating in 43°C water (HWI-43°C). Changes in neuromuscular function and fatigability, and physical performance-influencing factors such as psychological, thermoregulatory, neuroendocrine, and immune responses to whole-body hyperthermia were measured.

Kinetics of lipid indicators in response to short- and long-duration whole-body, cold-water immersion.

Cold exposure-induced secretion of stress hormones activates cold-defense responses and mobilizes substrates for increased energy demands to fuel thermogenesis. However, it is unclear whether acute cold exposure-induced stress hormone response kinetics affect circulating lipid parameter kinetics. Therefore, we aimed to investigate the 2-day kinetics of stress hormones (i.

Modulation of neuromuscular excitability in response to acute noxious heat exposure has no additional effects on central and peripheral fatigability.

Whole-body hyperthermia (WBH) has an adverse effect on the nervous system and neurophysiological performance. In the present study, we examined whether short-duration whole-body immersion in 45°C water (HWI-45°C), which produces a strong neural and temperature flux without inducing WBH, can increase or impair neurophysiological performance in humans. Fifteen men (aged 25 ± 6 years) were enrolled in this study and participated in three experiments: 1) a brief (5-min) immersion of the whole body in 37°C water (WI-37°C); 2) a brief (5-min) HWI-45°C; and 3) a control trial in a thermoneutral condition at an ambient temperature of 24°C and 60% relative humidity.

Vitamin C and E Treatment Blunts Sprint Interval Training-Induced Changes in Inflammatory Mediator-, Calcium-, and Mitochondria-Related Signaling in Recreationally Active Elderly Humans.

Sprint interval training (SIT) has emerged as a time-efficient training regimen for young individuals. Here, we studied whether SIT is effective also in elderly individuals and whether the training response was affected by treatment with the antioxidants vitamin C and E. Recreationally active elderly (mean age 65) men received either vitamin C (1 g/day) and vitamin E (235 mg/day) or placebo.

Response to Three Weeks of Sprint Interval Training Cannot Be Explained by the Exertional Level.

The all-out mode of sprint interval training (SIT) has been shown to be an efficient method for improving sports performance, exercise capacity, and aerobic fitness. Although the benefits of SIT are well described, the mechanisms underlying the different degrees of response remain largely unexplored. We aimed to assess the effects of exertion on the responsiveness to SIT.

Local knee heating increases spinal and supraspinal excitability and enhances plantar flexion and dorsiflexion torque production of the ankle in older adults.

Purpose: Aging is associated with progressive loss of active muscle mass and consequent decreases in resting metabolic rate and body temperature, and slowing of nerve conduction velocities and muscle contractility. These effectors compromise the ability of the elderly to maintain an upright posture during sudden balance perturbation, increase the risk of falls, and lead to self-imposed reduction in physical activity. Short-term superficial acute heating can modulate the neural drive transmission to exercising muscles without any marked change in deep-muscle temperature.

Modulation of Endothelial Glycocalyx and Microcirculation in Healthy Young Men during High-Intensity Sprint Interval Cycling-Exercise by Supplementation with Pomegranate Extract. A Randomized Controlled Trial.

The natural components of the pomegranate fruit may provide additional benefits for endothelial function and microcirculation. It was hypothesized that supplementation with pomegranate extract might improve glycocalyx properties and microcirculation during acute high-intensity sprint interval cycling exercise. Eighteen healthy and recreationally active male volunteers 22-28 years of age were recruited randomly to the experimental and control groups.

One night of sleep deprivation impairs executive function but does not affect psychomotor or motor performance.

The current study assessed the impact of one night of sleep deprivation on cognitive, motor and psychomotor performance. Thirty healthy young adult male subjects completed a 24 h control or 24 h sleep deprived trial. For the control trial, participants (N = 15) were allowed normal night sleep (~8 h).

Effects of severe whole-body hyperthermia on ovarian hormone and extracellular Hsp72 responses in young adult women.

Although acute thermal stress appears to be one of the most effective stressors that increase the intra- and extracellular concentrations of heat shock protein 72 (Hsp72), 17β-estradiol has been shown to inhibit heat-induced Hsp72 expression. To determine whether severe whole-body hyperthermia (increase in rectal temperature up to 39.5 °C) induced by lower-body heating is a sufficient stimulus to modulate hormonal (17β-estradiol, progesterone, prolactin, epinephrine, and norepinephrine) and extracellular Hsp72 responses, we investigated young adult women (21 ± 1 yr).

Acute effects of very low-volume high-intensity interval training on muscular fatigue and serum testosterone level vary according to age and training status.

Purpose: To compare the acute physiological responses of three different very low-volume cycling sessions (6 × 5 s, 3 × 30 s, and 3 × 60 s) and their dependence on age and training status.

Methods: Subjects were untrained young men (mean ± SD; age 22.3 ± 4.

Accelerated muscle contractility and decreased muscle steadiness following sauna recovery do not induce greater neuromuscular fatigability during sustained submaximal contractions.

Acute whole-body hyperthermia (WBH) increases blood markers concentration of stress, impairs motor drive to exercising muscles, and decreases resistance to neuromuscular fatigability. The functional natural residual consequences of WBH on neuromuscular functions remain unclear. We aimed to investigate the effects of residual WBH on voluntary and electrically induced ankle plantar flexor contractility properties, motor drive transmission (reflexes), muscle torque steadiness, resistance to neuromuscular fatigability, and markers of stress as the body temperature recovers naturally to normothermia.

The Effect of Three Different Strategies Based on Motor Task Performance on Neuromuscular Fatigue in Healthy Men and Men with Multiple Sclerosis.

: Fatigue during physical activity occurs because of decreased neuromuscular function. The aim of this study was to evaluate the effect of three different strategies based on motor task performance on neuromuscular fatigue in healthy men and men with multiple sclerosis (MS). : We studied age-matched (18⁻43 years of age) healthy men ( = 15) and men with MS ( = 9).

Very Low Volume High-Intensity Interval Exercise Is More Effective in Young Than Old Women.

We investigated the acute neuromuscular and stress responses to three different high-intensity interval training sessions in young (age 19.5 ± 1.3 years) and older (age 65.

Three different motor task strategies to assess neuromuscular adjustments during fatiguing muscle contractions in young and older men.

Healthy aging is associated with a marked decline in motor performance. The functional consequences of applying varying novel or unexpected motor stimuli during intermittent isometric prolonged (fatiguing) motor tasks for lower limb neuromuscular fatigability and steadiness, perception of effort, and blood markers of stress in healthy aged men compared with young men have not been investigated. The participants in this study were 15 young men (aged 22 ± 4 years) and 10 older men (aged 67 ± 6 years).

Psychological and Physiological Biomarkers of Neuromuscular Fatigue after Two Bouts of Sprint Interval Exercise.

The main aim of our study was to determinate whether a repeated bout (RB) (vs. first bout [FB]) of sprint interval cycling exercise (SIE) is sufficient to mitigate SIE-induced psychological and physiological biomarker kinetics within 48 h after the exercise. Ten physically active men (age, 22.

Gender differences in residual effect of prior drop jumps on oxygen uptake during heavy cycling exercise.

Background And Objective: Unaccustomed eccentric or eccentric-concentric exercise leaves us stiff and sore the next day and can cause muscle damage. The data about the residual effect of prior eccentric-concentric exercises on oxygen uptake (VO) during constant cycling exercise in women or the data about differences of such effect between genders are scarce. Therefore, the aim of this study was to assess differences of the residual effect of PDJ on VO during HCE and indirect muscle damage parameters between women and men.

Sex-specific reliability and multidimensional stability of responses to tests assessing neuromuscular function.

The objective of this study was to estimate sex-specific effects in the test-retest cross-reliability of peripheral and central changes in nonlinear and linear measures of a surface electromyography signal during a brief (5 second) and sustained (2minute) isometric maximal voluntary contraction, combined with superimposed electrical stimulation involving the ankle plantar flexors over five identical trials. In this study, we repeated the testing protocol used in our previous study of 10 women (age 20.9, SD=0.

Physiological and Psychological Responses during Exercise and Recovery in a Cold Environment Is Gender-Related Rather Than Fabric-Related.

We evaluated gender-specific effects of two types of undergarments on exercise-induced physiological and psychological stress and subsequent recovery in cold conditions for male and female participants. Ten healthy men and eleven healthy women (25.0 ± 1.

Intratendinous Air Phenomenon: A New Ultrasound Marker of Tendon Damage?

To explore the presence of intratendinous air in physically active males after different types of strenuous physical exercise. To detect foci (air bubbles) in the quadriceps femoris tendon (QFT) and the proximal and distal parts of the patellar tendon, ultrasound examination was performed under two conditions: (1) after high-intensity cycling on a cycle ergometer (metabolic); (2) after 200 drop jumps (exercise-induced muscle damage). Based on the results of these two interventions, the presence of air in the tendons after 100 drop jumps was examined further with frequently repeated ultrasound measurements.

Heat transfer and loss by whole-body hyperthermia during severe lower-body heating are impaired in healthy older men.

Most studies demonstrate that aging is associated with a weakened thermoregulation. However, it remains unclear whether heat transfer (for heat loss) from the lower (uncompensable) to the upper (compensable) body during passively-induced severe lower-body heating is delayed or attenuated with aging. Therefore, the main purpose of this study was to investigate heat transfer from uncompensable to compensable body areas in young men and healthy older men during passively-induced whole-body hyperthermia with a demonstrated post-heating change in core body (rectal; T) temperature.

Serum brain-derived neurotrophic factor and interleukin-6 response to high-volume mechanically demanding exercise.

Introduction: The aim of this study was to follow circulating brain-derived neurotrophic factor (BDNF) and interleukin-6 (IL-6) levels in response to severe muscle-damaging exercise.

Methods: Young healthy men (N = 10) performed a bout of mechanically demanding stretch-shortening cycle exercise consisting of 200 drop jumps. Voluntary and electrically induced knee extension torque, serum BDNF levels, and IL-6 levels were measured before and for up to 7 days after exercise.

Effect of sprint cycling and stretch-shortening cycle exercises on the neuromuscular, immune and stress indicators in young men.

Selection of optimal physical load is essential for desired adaptation including health benefits. We hypothesized that neuromuscular, immune and stress indicators will be higher after energy demanding sprint interval exercise (SIE) than to mechanically demanding stretch-shortening cycle exercise (SSE). The main aim of this study was to assess and compare the kinetics of blood brain-derived neurotrophic factor (BDNF), norepinephrine (NE) and cortisol (as stress indicators) and proinflammatory (IL-6) and anti-inflammatory (IL-10) cytokines within 24 hours after metabolically demanding SIE and after muscle damage inducing SSE.

Effect of constant, predictable, and unpredictable motor tasks on motor performance and blood markers of stress.

An unfamiliar or novel physical stimulus induces activation of dopaminergic neurons within the brain and greater activity in areas involved in emotion; considering this, we aimed to establish whether unpredictable prolonged (fatiguing) motor task (vs. constant vs. predictable) evokes greater dopaminergic activity, enhances neuromuscular performance, motor accuracy, and perception of effort, and delays overall central fatigue.