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Fasting is related to glucose intolerance and insulin resistance, but it is unknown whether the duration of fasting influences these factors. We explored whether prolonged fasting increases norepinephrine and ketone concentrations and decreases core temperature to a greater extent than short-term fasting; if so, this should lead to improved glucose tolerance. Forty-three healthy young adult males were randomly assigned to undergo a 2-d fast, 6-d fast or the usual diet. Changes in rectal temperature (TR), ketone and catecholamine concentrations, glucose tolerance and insulin release in response to an oral glucose tolerance test were assessed. Both fasting trials increased ketone concentration, and the effect was larger after the 6-d fast (P < 0·05). TR and epinephrine concentration increased only after the 2-d fast (P < 0·05). Both fasting trials increased the glucose area under the curve (AUC) (P < 0·05), but the AUC remained higher than the baseline value after participants returned to their usual diet in the 2-d fast group (P < 0·05). Neither fasting had an immediate effect on the insulin AUC, although it increased after return to their usual diet in the 6-d fast group (P < 0·05). These data suggest that the 2-d fast elicited residual impaired glucose tolerance, which may be linked to greater perceived stress during short-term fasting, as shown by the epinephrine response and change in core temperature. By contrast, prolonged fasting seemed to evoke an adaptive residual mechanism that is related to improved insulin release and maintained glucose tolerance. [ABSTRACT FROM AUTHOR]

Background and Objectives: 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., a ≈ 2.5 °C increase in rectal temperature (Tre) from overnight-fast baseline value, on cognitive functioning in old and young men and to explore factors, such as stress and thermophysiological strain, that could influence such changes. Materials and Methods: Ten young (19–21 years of age) and nine old (61–80 years of age) healthy men underwent an experimental trial with passive lower-body heating in hot water immersion (HWI) at 43 °C (HWI–43 °C) until Tre reached 39 °C in old adults and 39.5 °C in young adults. Cognitive performance and cortisol concentration were assessed before and after HWI, and the physiological strain index (PSI) was assessed during HWI–43 °C. Results: PSI was lower and cortisol concentration was greater after HWI–43 °C in the old group compared with the young group (p < 0.05). Surprisingly, hyperthermia improved cognitive flexibility only in old adults, whereas short-term and visual recognition memories were maintained in both age groups. Conclusions: A ≈ 2.5 °C increase in rectal temperature can improve executive function in old adults, and this increase parallels the increased cortisol concentration and the lower thermophysiological strain under severe WBH conditions. [ABSTRACT FROM AUTHOR]

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. Results: A slower increase in rectal temperature, and a lower heart rate, thermal sensation, and sweating rate were observed in older males than young males in response to HWI‐43°C trial (p < 0.05). Nevertheless, prolactin increased more in response to hyperthermia in young males, while interleukin‐6 and cortisol levels increased more in older males (p < 0.05). Peripheral dopamine levels decreased in older males and increased in young males in response to hyperthermia (p < 0.05). Surprisingly, older males demonstrated greater neuromuscular fatigability resistance and faster maximal voluntary contraction (MVC) torque recovery after a 2‐min sustained isometric MVC task under thermoneutral and severe hyperthermic conditions (p < 0.05). Conclusion: Neuromuscular performance during fatigue‐provoking sustained isometric exercise under severe whole‐body hyperthermia conditions appears to decline in both age groups, but a lower relative decline in torque production for older males may relate to lower psychological and thermophysiological strain along with a diminished dopamine response and prolactin release. [ABSTRACT FROM AUTHOR]

The effect of globally recommended levels of physical activity on cognition andmotor behavior is not completely understood. Therefore, themain aim of this study was to assess the effect of 300 minutes per week of moderate-intensity aerobic exercise on cognitive and motor performance among overweight and obese working-age women. Methods: Overweight and obese participants aged 38-56 years were randomized to either a control or an experimental group performing aerobic exercise at 50% to 60% of the peak oxygen consumption for a 2-month period. Changes in aerobic fitness, cardiac autonomic function, brain-derived neurotropic factor levels, and cognitive and motor performance were assessed. Results: Although aerobic exercise reduced body weight (P < .05) and improved peak oxygen consumption (P < .05), the brain-derived neurotropic factor levels and cognitive and motor performance remained unchanged. Heart rate and blood pressure decreased (P < .05), whereas heart rate variability indices were not affected. No significant correlations between changes in heart rate variability indices and cognition were observed. Conclusions: Two months of moderate-intensity aerobic exercise decreased sympathetic activity and improved cardiovascular fitness but had no impact on cognition ormotor control among thesemiddle-aged, overweight, and obese women. [ABSTRACT FROM AUTHOR]

Background: The benefits of weight loss programs on mood, cognitive, and motor behavior are largely limited to those of calorie restriction or exercise alone. Our aim was to investigate the effect of combined calorie restriction and aerobic exercise intervention on mood, brain activity, and cognitive and motor behavior in overweight and obese women. Methods: Participants aged 36–56 years were randomized to either a control or an experimental group (aerobic exercise + 12.5% energy intake reduction) for a 6-month period. Changes in brain-derived neurotrophic factor levels, mood, prefrontal cortex activity, cognitive and motor performance were assessed. Results: Confusion and depression increased in the control group (P <.05), whereas tension decreased in the experimental group (P <.05). Brain-derived neurotrophic factor level and learning of a speed–accuracy task remained unchanged. Although prefrontal cortex activity and executive functions were not affected, the reaction time of visual scanning and associative learning were improved in the experimental group (P <.05). An improvement in reaction time during the speed–accuracy task was observed (P <.05). Conclusion: Combined calorie restriction and aerobic exercise intervention improved the psychosocial state, had little impact on cognition, and no effect on brain activity and learning of the speed–accuracy task. [ABSTRACT FROM AUTHOR]

Metabolites of the kynurenine (KYN) pathway of tryptophan (TRP) degradation have attracted interest as potential pathophysiological mediators and future diagnostic biomarkers. A greater knowledge of the pathological implications of the metabolites is associated with a need for a better understanding of how the normal behaviour and physiological activities impact their concentrations. This study aimed to investigate whether fasting (FAST) and whole-body cold-water immersion (CWI) affect KYN pathway metabolites. Thirteen young women were randomly assigned to receive the 2-d FAST with two 10-min CWI on separate days (FAST-CWI), 2-d FAST without CWI (FAST-CON), 2-d two CWI on separate days without FAST (CON-CWI) or the 2-d usual diet without CWI (CON-CON) in a randomised crossover fashion. Changes in plasma concentrations of TRP, kynurenic acid (KYNA), 3-hydroxy-kynurenine (3-HK), picolinic acid (PIC), quinolinic acid (QUIN) and nicotinamide (NAA) were determined with ultra-performance liquid chromatography-tandem mass spectrometer. FAST-CWI and FAST-CON lowered TRP concentration (P < 0·05, η p2 = 0·24), and increased concentrations of KYNA, 3-HK and PIC (P < 0·05, η p2 = 0·21–0·71) with no additional effects of CWI. The ratio of PIC/QUIN increased after FAST-CWI and FAST-CON trials (P < 0·05) but with a blunted effect in the FAST-CWI trial (P < 0·05) compared with the FAST-CON trials (η p2 = 0·67). Concentrations of QUIN and NAA were unaltered. This study demonstrated that fasting for 2 d considerably impacts the concentration of several metabolites in the KYN pathway. This should be considered when discussing the potential of KYN pathway metabolites as biomarkers. [ABSTRACT FROM AUTHOR]

Kinesiotaping (KT) is common in musculoskeletal rehabilitation, but whether it is efficacious for surgically untreated anterior cruciate ligament (ACL) ruptures is unknown. Therefore, we evaluated whether a strategy of physiotherapy plus KT would be superior to a strategy of physiotherapy alone on subsequent proprioception and motor function. Men aged 28.1 ± 6.7 years with complete ACL ruptures were randomized to either a control (physiotherapy) or an experimental group (physiotherapy + KT) for a 4-week period. Changes in balance were assessed on the injured leg using a force platform. Knee angle reproduction, maximal voluntary contraction (MVC), and rate of force development (RFD) were measured using dynamometry, and pain was recorded using a visual analog scale. Decreases in knee pain and improvements in angle reproduction were observed in both groups (p < 0.05), with a greater effect on angle reproduction in the experimental group (p < 0.05). Both groups demonstrated increased isometric knee flexor MVC and RFD values (p < 0.05), but an increase in RFD of the knee extensors was observed only in the experimental group (p < 0.05). Furthermore, the MVC of concentric knee flexors at 60°·s-1 increased only in the experimental group (p < 0.05), whereas concentric MVC at 180°·s-1-resulting in greater hamstring-to-quadriceps ratios-increased in both groups (p < 0.05). Balancing ability on the injured leg increased only in the experimental group (p < 0.05). Thus, KT plus physiotherapy was beneficial in the treatment of proprioception, strength, and static balance in these individuals with an ACL rupture. [ABSTRACT FROM AUTHOR]

Background: 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. Methods: 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. Before and after the immersions, neuromuscular function (electromyographic activity, reflexes, electrically and voluntary induced torque production, voluntary muscle activation level) were tested. To provoke central inhibition, the participants performed a sustained 2-min maximal voluntary contraction (MVC). Results: Thermophysiological strain was greater after HWI-45°C than after WI-37°C. Electrophysiological modulations of motor drive transmission and peripheral modulations of muscle contractility properties in response to HWI-45°C seemed to have little effect on central activation of the exercising muscles and no effect on MVC production. Conclusion: Although exposure to acute noxious heat was effective in evoking neuromuscular excitability, the increases in core temperature (~0.2°C) and muscle temperature (~0.6°C) did not induce moderate or severe WBH. These changes did not seem to affect central structures; that is, there were no additional increases in central and/or peripheral fatigue during a sustained 2-min MVC. [ABSTRACT FROM AUTHOR]

Background: Noxious acute cold stimuli cause cold shock via the sympathetic nervous system. However, no studies have investigated respiratory “heat shock” in response to noxious acute heat stimuli (( 42 C). Methods: In the present study, we examined whether short-duration whole-body immersion (for 5 min) in noxious hot water (45 C) is a sufficient stimulus to induce a respiratory acute shock response. Results and conclusion: Our results indicate that short-duration whole-body immersion in noxious 45 C water produces a significantly greater body temperature, heart rate, and perceptual and respiratory strain than immersion in innocuous warm 37 C water (p < .05). The initial first minute of hot water immersion (HWI) at 45 C (vs. immersion at 37 C) caused a cardiorespiratory shock response, which manifested as acute hyperventilation, and increased ventilatory tidal volume, respiratory exchange ratio, and heart rate (p < .05). Adjustment to this initial respiratory heat shock response within the first minute of immersion was observed as compared with remaining HWI time (1–5 min). Intriguingly, the time-course kinetics of breathing frequency, oxygen uptake, and carbon dioxide washout did not differ between whole-body immersion at 37 C and immersion at 45 C, but were higher than in control thermoneutral conditions of an empty bath (p < .05). This may be because of events initiated not only by the water temperature but also by the change in the hydrostatic pressure acting upon the body when immersed in the water bath. [ABSTRACT FROM AUTHOR]

Background: One of the most challenging environmental extremes is immersion in cold/icy water, and consequent common assumption is that even a brief exposure to cold can lead to cold-related illnesses. The increase in the concentrations of the stress hormones cortisol, epinephrine (Epi), and norepinephrine (NE) in response to acute cold stress are thought to suppress the release of proinflammatory cytokines. No previous study has explored the residual consequences of whole-body short-term cold-water immersion (CWI; 14 °C for 10 min) on the immune response in healthy non-acclimated young adult men (aged 20–30 years). Materials and methods: In the current study, we tested the hypothesis that short-term acute whole-body CWI would induce high blood levels of cortisol, NE, and Epi, which in turn would increase circulating leukocyte numbers and delay the production of proinflammatory cytokines (tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), and IL-6). Results: Short-term whole-body CWI produced a stressful physiological reaction, as manifested by hyperventilation and increased muscle shivering, metabolic heat production, and heart rate. CWI also induced the marked release of the stress hormones Epi, NE, and cortisol. The change in IL-6 concentration after CWI was delayed and TNF-α production was decreased, but IL-1β was not affected within 48 h after CWI. A delayed increase in neutrophil percentage and decrease in lymphocyte percentage occurred after CWI. Conclusion: These findings suggest that, even though CWI caused changes in stress and immune markers, the participants showed no predisposition to symptoms of the common cold within 48 h after CWI. [ABSTRACT FROM AUTHOR]

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). For the sleep deprived trial, participants (N = 15) did not sleep for 24 h. Cognitive performance during go/no-go, Stroop and simple reaction tasks, psychomotor performance during speed-accuracy tasks with fixed and unfixed targets, and motor performance during countermovement jump, hand grip strength, and 30-s maximal voluntary contraction tasks were evaluated on day 1 at 8 am and 7 pm and on day 2 at 8 am. One night of sleep deprivation impaired psychological well-being and executive function but did not affect simple reaction time, the capacity for arm and leg muscle contraction, motor control performance during a speed-accuracy task with both fixed and unfixed targets, and central and peripheral motor fatigue in the 30 s maximal voluntary contraction task. The present study showed that one night of sleep deprivation resulted in executive function deterioration but did not modify motor control or maximal effort requiring performance of motor tasks. [ABSTRACT FROM AUTHOR]

Background. It is clinically important to determine the factors that increase fat oxidation and have potential to improve body composition in overweight and obese individuals. Thus, the aim of the present study was to compare the effects of a 2-day very low-calorie diet and 2-day zero-calorie diet on fat oxidation and prospective food consumption in overweight and mildly obese adults. Methods. Eighteen subjects (body mass index above 25 kg/m²) aged 19-33 years were tested under two conditions allocated randomly: 2-day zero-calorie diet with water provided ad libitum and 2-day very-low calorie diet. Appetite sensations, mood state, inhibitory control, and substrate oxidation were evaluated before and after each diet. Results. Greater increase in fat oxidation (p < .05) was observed after zero-calorie diet when compared to a very low-calorie diet. Results showed that both diets increased (p < .05) sensation of hunger and prospective food consumption, whereas no changes were observed in inhibitory control. Greater decrement for vigor (p < .05) was observed after zero-calorie diet when compared to a very low-calorie diet, whereas other mood states were not affected by it. Conclusion. Intermittent fasting with zero-calorie diet may boost fat oxidation to a greater extent when compared to very low-calorie diet and may assist with weight loss in overweight and mildly obese adults. [ABSTRACT FROM AUTHOR]

Background: Although the effects of mental fatigue on cognitive–motor function and psychological state in young adults are well-documented, its effects in the elderly are not completely understood. The aim of this study was to estimate the effect of prolonged cognitive load on the indicators of psychological, cognitive, and motor functions. Methods: Fifteen young and 15 elderly men were asked to perform a 2 h “Go/NoGo” task. Psychological state (mood and motivation), cognitive (prefrontal cortex activity and cognitive performance), and motor (motor cortex excitability and grip strength) functions were measured before and after the task. During the 2 h task, both groups had a significantly similar increase in the number of “Incorrect NoGo” errors. Only in young men reaction time (RT) of “Incorrect NoGo” and intraindividual variability of RT of “Incorrect NoGo” significantly increased during task. After the task, handgrip strength decreased for the young men, whereas latency of motor evoked potentials prolonged both groups. Nevertheless, both groups indicated that they felt fatigue after the 2 h task; we observed that mental demand increased, whereas intrinsic motivation and mood decreased only in young men. Prolonged task decreased the switching/rest ratio of oxygenated hemoglobin for the young and the elderly men; however, greater for elderly than young men. Interestingly, the more the prefrontal cortex was activated before the 2 h task during the switching task, the fewer of “Incorrect NoGo” errors made by the young men and the greater the number of errors made by the elderly men. Conclusion: Because of the greater mental load and (possibly) greater activation of prefrontal cortex during the 2 h “Go/NoGo” task, there was greater mental and neuromuscular performance fatigue in young men than in elderly men. [ABSTRACT FROM AUTHOR]

Background. It is well established that intermittent long-term fasting, during which a very low-calorie diet is allowed 2-days a week, improves weight loss, mood and cognitive functions. However, we are not aware of any previous studies on the effect of a 2-day very low-calorie diet on brain functioning. Thus, the purpose of this study was to determine the effect of 2-day very low-calorie diet on perceived stress, cognitive functions and mood in overweight and obese men. Methods. Nine young adult men (body mass index (BMI) from 26.7 to 32.1 kg/m²) completed a 2-days very low-calorie diet (536 kcal) and 2-day usual diet program in a randomized order. Perceived stress (subjective stress rating and cardiovascular response), cognitive performance, and mood were evaluated before and after both diets. Results. A subjective stress rating in relation to the very low-calorie diet condition was 37.4 ± 18.7. There were no detectable effects of acute calorie restriction on cardiovascular response (heart rate and blood pressure) and on any aspect of cognitive performance. Meanwhile, sense of vigor increased (p < .05) and negatively correlated with BMI (r = -.780, p < .05). Conclusions. The two-day very low-calorie diet evoked a mild stress, which did not affect sympathetic nervous system response and cognitive performance in overweight and obese men. Furthermore, very low-calorie diet increased vigor, which was strongly associated with decreased body mass index. [ABSTRACT FROM AUTHOR]

Objectives. The acute fasting-induced cardiovascular autonomic response and its effect on cognition and mood remain debatable. Thus, the main purpose of this study was to estimate the effect of a 48 h, zero-calorie diet on autonomic function, brain activity, cognition, and mood in amateur weight lifters. Methods. Nine participants completed a 48 h, zero-calorie diet program. Cardiovascular autonomic function, resting frontal brain activity, cognitive performance, and mood were evaluated before and after fasting. Results. Fasting decreased (p<0.05) weight, heart rate, and systolic blood pressure, whereas no changes were evident regarding any of the measured heart rate variability indices. Fasting decreased (p<0.05) the concentration of oxygenated hemoglobin and improved (p<0.05) mental flexibility and shifting set, whereas no changes were observed in working memory, visuospatial discrimination, and spatial orientation ability. Fasting also increased (p<0.05) anger, whereas other mood states were not affected by it. Conclusions. 48 h fasting resulted in higher parasympathetic activity and decreased resting frontal brain activity, increased anger, and improved prefrontal-cortex-related cognitive functions, such as mental flexibility and set shifting, in amateur weight lifters. In contrast, hippocampus-related cognitive functions were not affected by it. [ABSTRACT FROM AUTHOR]

Background. The effectiveness of outpatient mobile laser intervention on specific treatment goals has not been fully explored. Thus, the aim of the study was to examine the effect of orthopaedic knee brace with laser on knee joint function, pain and swelling. Methods. Volunteers were divided into two experimental groups: chronic pain (n = 20, knee pain > 6 months) and acute pain (n = 20, knee pain < 1 week), and one control (n = 20, placebo) group. Subjects in all groups were immobilized in a knee brace for 4 weeks. In addition, the experimental groups underwent low-intensity laser therapy, whereas control group underwent pseudo-laser therapy, every second day for 10 min. The sequences of the tests were as follows: (a) clinical assessments and evaluation of knee extension and flexion amplitude, swelling, Lysholm subjective assessment questionnaire, VAS pain scale, (b) evaluation of balance using Kistler platform, (c) muscle peak torque and isometric torque variability assessment using isokinetic dynamometry. All tests were performed twice - before and after intervention. Results. Knee brace with laser is effective treatment for the reduction of pain, swelling, and recovering of daily functions (p < .05). Operation of the complex device is particularly effective in treating knee pain in the acute period (p < .05). Conclusions. Knee brace with laser therapy in the rehabilitation period ensures faster healing of patients compared to wearing only knee brace, particularly in acute pain, while muscle strength and proprioception remains depressed. [ABSTRACT FROM AUTHOR]

Background. There is evidence of greater whole body cooling induced unpredictable task switching and memory deterioration in men than in women; however, it is not known how whole body cooling affects attention stability. This study aimed at identifying if there are any gender-specific differences in the effect of cold water immersion-induced stress on attention stability. Methods. Thirteen men and thirteen women were exposed to acute cold stress by immersion in 14°C water until rectal temperature reached 35.5°C or for a maximum of 170 min. Thermoregulatory response (i.e. changes of body temperature and metabolic heat production) and attention stability response (i.e. Schulte table (less cognitively demanding task) and Schulte-Gorbov table (more cognitively demanding task)) were monitored. Results. During cold stress, body temperature variables decreased (p < .05) and did not differ between genders. Metabolic heat production was greater (p < .05) in men than in women. Body cooling significantly increased (P < .05) the duration of Schulte table performance for both genders, whereas an increase (p < .05) of the duration of Schulte-Gorbov table performance was observed only in men. Conclusion. This is the first study to find the evidence supporting the idea of gender-specific and task-dependent attention stability response after whole body cooling. Whole body cooling induced stress had similar influence on simple attention stability task in men and women, whereas more complex task was adversely affected only in men. This greater men's decrement of complex task performance can be associated with their greater catecholamines- induced metabolic heat production. [ABSTRACT FROM AUTHOR]

Copyright of Education. Physical Training. Sport / Ugdymas. Kûno kultûra. Sportas is the property of Lithuanian Sports University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Education. Physical Training. Sport / Ugdymas. Kûno kultûra. Sportas is the property of Lithuanian Sports University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Education. Physical Training. Sport / Ugdymas. Kûno kultûra. Sportas is the property of Lithuanian Sports University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The aim of this study was to determine the effect of a 10-week tai chi intervention on psychoemotional state, cognition, and motor learning in older adults during the COVID-19 pandemic. Participants aged 60–78 years were randomized to either a control group (n = 15) or a tai chi group (n = 15) for a 10-week period. The tai chi group received two, 8-form tai chi classes of 60 min duration per week. Changes in psychoemotional state, cognition, and the learning of fast and accurate reaching movements were assessed. In addition, the potential roles of the autonomic nervous system and brain-derived neurotrophic factor (BDNF) were investigated. Tai chi practice decreased (P < 0.05) perceived stress, whereas no change in autonomic nervous system activity was observed. Improvements in mental switching correlated with decreased depressive symptoms and increased BDNF levels (P < 0.05), whereas improvements in inhibitory control tended to correlate with BDNF levels (P = 0.08). Improvements in visuospatial processing tended to correlate with decreased depressive symptoms (P = 0.07) while improved visuospatial processing correlated with improved motor planning during learning tasks (P < 0.05). This study suggests that tai chi is an effective intervention that can be delivered under pandemic conditions to improve mental and physical function in older adults. • Healthy older adults practiced tai chi for 10 weeks during the COVID-19 pandemic. • Tai chi improved cognition and learning of fast and accurate reaching movements. • Cognitive improvements correlated with changes in depression and BDNF levels. • Motor learning improvements were associated with improved cognition. [ABSTRACT FROM AUTHOR]

• Effects of 48-h fasting were investigated in overweight and obese women. • Fasting increased subjective fatigue and perceived stress. • Fasting increased cortisol levels, but autonomic nervous system was not affected. • Fasting declined cognitive flexibility, whereas balance was improved. The purpose of this study was to investigate the effects of a 48-h fast on evoked stress, mood, and cognitive and motor functions in overweight and obese older women. Eleven women (body mass index >25 kg/m2) aged 63–80 years were tested under two randomly allocated conditions: 48-h zero-calorie diet with water provided ad libitum and 48-h usual diet. Autonomic function, cortisol levels, mood state, cognitive performance, visuomotor coordination, motor speed, and balance were evaluated before and after each diet. Fasting increased (P < 0.05) cortisol levels, whereas no changes were observed in heart rate and its variability. Fasting increased (P < 0.05) fatigue, prolonged (P < 0.05) reaction time in the two-choice reaction time test and decreased (P < 0.05) the velocity vector of the center of pressure with eyes closed, whereas no changes in performance were observed in the pursuit tracking and finger tapping tests. Thus, although a 48-h fast resulted in greater hypothalamic–pituitary–adrenal axis activity in overweight and obese older women, autonomic nervous system activity was not affected. Fasting increased fatigue and decreased mental flexibility, but improved balance. [ABSTRACT FROM AUTHOR]

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.e., cortisol, epinephrine, and norepinephrine) and the lipid profile (i.e., total cholesterol [TC], high-density lipoprotein [HDL] cholesterol, low-density lipoprotein [LDL] cholesterol, and triglycerides) in response to whole-body long- (intermittent 170 min; 170-CWI) or short-duration (10 min; 10-CWI) cold-water immersion (CWI; 14 °C water) in 17 healthy, young, adult men. Both CWI trials induced a marked release of the stress hormones, epinephrine, and norepinephrine, with higher concentrations detected after 170-CWI (p < 0.05) and a disrupted diurnal peak of cortisol lasting for a few hours. 170-CWI increased triglyceride levels from immediately after until 2 h after CWI, thereafter the concentration decreased at 4 h, 6 h, 1 day and 2 days after CWI (p < 0.05). Furthermore, the HDL-cholesterol level increased immediately after and at 6 h after 170-CWI (p < 0.05), while TC and LDL-cholesterol levels were not altered within 2 days. Lipid parameters were not affected within the 2 days after 10-CWI. Although both CWIs decreased deep body temperature and increased stress hormone levels for a few hours, only long-duration CWI induced changes in the circulating lipid profile within 2 days after CWI. This should be considered when discussing therapeutic protocols to improve circulating lipid profiles and ameliorate diseases associated with such profiles. [ABSTRACT FROM AUTHOR]

Despite studies investigating the effect of yoga on cognitive and motor functioning in older adults, the effect on dual-task performance and motor learning and the specific mechanisms underlying the positive effect of yoga remain unclear. Thus, the aim of this study was to investigate the effects of yoga on cognition, balance under single- and dual-task conditions, and motor learning. The potential role of brain-derived neurotrophic factor (BDNF) in induced improvement was also explored. Participants aged 60–79 years were randomized to either a control group (n = 15) or a yoga group (n = 18) for a 10-week period. The yoga group received 90-min duration yoga classes two times per week. Changes in cognition, balance under single- and dual-task conditions, and learning fast and accurate reaching movements were assessed. Yoga practice decreased (P < 0.05) the velocity vector of the center of pressure under single- and dual-task conditions, whereas no changes in cognitive performance were observed. Although reaction and movement times during learning were decreased in both groups (P < 0.05), a faster reaction time (P < 0.05) and shorter movement time (P < 0.05) were observed in the yoga group than in the control group. Significant moderate relationships (P < 0.05) between changes in BDNF levels and functional improvements were observed. Thus, 10 weeks of yoga practice resulted in improved balance and learning in the speed–accuracy motor task that were mediated by increased BDNF levels, but had no impact on cognition in older adults. • Older adults performed 90-min duration yoga two times per week for 10 weeks. • Yoga practice had no effect on cognition. • Yoga improved motor learning and balance under single- and dual-task conditions. • Balance and motor learning improvements were associated with increased BDNF levels. • No improvement in mood and reduction in stress were observed. [ABSTRACT FROM AUTHOR]

Background/objectives: Prolonged fasting triggers a stress response within the human body. Our objective was to investigate the impact of prolonged fasting, in conjunction with stress, on kynurenine pathway metabolites., Subjects/methods: Healthy males were divided into fasting group (zero-calorie-restriction) for 6 days (FAST, n = 14), and control group (CON, n = 10). Blood and saliva samples were collected at baseline, Day 2, Day 4, Day 6 during fasting period, and 1 week after resuming regular diet. Plasma levels of kynurenine pathway metabolites were measured using ultra-performance liquid chromatography-mass spectrometry (UPLC-MS/MS). Plasma and salivary samples were analyzed for stress markers., Results: A pronounced activation of the kynurenine pathway in individuals on FAST trial was revealed. Concentrations of picolinic acid (PIC), kynurenic acid (KYNA) and 3-hydroxykynurenine (3-HK) were significantly increased, with peak levels observed on Day 6 (P < 0.0001). Conversely, concentrations of tryptophan (TRP) and quinolinic acid (QUIN) decreased (P < 0.0001), while kynurenine (KYN) and nicotinamide (NAM) levels remained stable. Cortisol and noradrenaline concentrations remained unchanged. However, adrenaline levels significantly increased on Day 4 within FAST compared to CON (P = 0.005). Notably, all deviations in kynurenine pathway metabolite levels returned to baseline values upon resuming regular diet following the 6-day fasting regimen, even when weight and BMI parameters were not restored., Conclusions: Extended fasting over 6 days induces the kynurenine pathway and has minimal effects on stress markers. Restoration of metabolite concentrations upon regular feeding implies rapid adaptation of the kynurenine pathway synthetic enzymes to maintain homeostasis when faced with perturbations., (© 2024. The Author(s).)

Background: Though previous research has shown that tai chi improves balance and reduces falls risk in older adults, the mechanisms responsible for this improvement remains not fully investigated. Thus, the aim of this study was to determine the efficacy of tai chi practice in improving weight loss, cognitive processes and molecular mechanisms underlying balance control in older adults., Methods: Subjects aged 60-79 years were randomized to either a control group (N.= 15) or a tai chi group (N.= 15) for a 10-week period during COVID-19 pandemic. Changes in anthropometric characteristics, sustained attention, balance, myokines levels were assessed., Results: Weight increased in control group (P<0.05), whereas it remained unchanged in tai chi group. Tai chi improved (P<0.05) accuracy during go/no-go task, center of pressure velocity in the Romberg stance position with eyes closed under single and dual-task conditions, and increased (P<0.05) levels of brain-derived neurotrophic factor and irisin, while in control group center of pressure velocity with eyes open tended to decrease. Changes in balance within 10 weeks were moderately correlated (P<0.05) with changes in anthropometric characteristics, sustained attention and levels of myokines., Conclusions: Thus, 10 weeks of tai chi practice induced improvements in balance, which was related with improved sustained attention, and increased myokines levels, whereas decrements in balance under pandemic conditions were related with weight gain in older adults.

Metabolites of the kynurenine (KYN) pathway of tryptophan (TRP) degradation have attracted interest as potential pathophysiological mediators and future diagnostic biomarkers. A greater knowledge of the pathological implications of the metabolites is associated with a need for a better understanding of how the normal behaviour and physiological activities impact their concentrations. This study aimed to investigate whether fasting (FAST) and whole-body cold-water immersion (CWI) affect KYN pathway metabolites. Thirteen young women were randomly assigned to receive the 2-d FAST with two 10-min CWI on separate days (FAST-CWI), 2-d FAST without CWI (FAST-CON), 2-d two CWI on separate days without FAST (CON-CWI) or the 2-d usual diet without CWI (CON-CON) in a randomised crossover fashion. Changes in plasma concentrations of TRP, kynurenic acid (KYNA), 3-hydroxy-kynurenine (3-HK), picolinic acid (PIC), quinolinic acid (QUIN) and nicotinamide (NAA) were determined with ultra-performance liquid chromatography-tandem mass spectrometer. FAST-CWI and FAST-CON lowered TRP concentration ( P < 0·05, η p 2 = 0·24), and increased concentrations of KYNA, 3-HK and PIC ( P < 0·05, η p 2 = 0·21-0·71) with no additional effects of CWI. The ratio of PIC/QUIN increased after FAST-CWI and FAST-CON trials ( P < 0·05) but with a blunted effect in the FAST-CWI trial ( P < 0·05) compared with the FAST-CON trials ( η p 2 = 0·67). Concentrations of QUIN and NAA were unaltered. This study demonstrated that fasting for 2 d considerably impacts the concentration of several metabolites in the KYN pathway. This should be considered when discussing the potential of KYN pathway metabolites as biomarkers.

Background: Limited and contradictory data are available regarding the acute effects of endurance exercises on cognition and retinal microcirculation. Thus, we aimed to evaluate the acute effects of sport-specific high-intensity interval training (HIIT) on cognition and retinal vessel diameters in experienced amateur boxers., Methods: Eleven young (age 22.8±2.9 years) men with 10.7±4.8 years of boxing experience completed two sessions in random order: high-intensity intermittent punching load and passive rest. Cardiovascular response, retinal vessel diameters, and cognitive performance were evaluated at baseline, during exercise, and immediately after each session., Results: Increased heart rate during intermittent punching load (P<0.05) reaching 91.2±3.7% of the maximal heart rate was observed. The HIIT improved cognitive flexibility and inhibitory control (P<0.05), while the working memory and motor speed were not affected. Significant dilatation of temporal retinal venules (P<0.05) was observed after the HIIT compared with the values before the HIIT, resulting in a decreased arteriolar-to-venular diameter ratio (P<0.05)., Conclusions: At the functional level, an improvement in executive function due to intermittent high intensity punching load was observed, while at the physiological level, retinal venular dilatation was observed in experienced amateur boxers.

Background: Although changes in retinal vessel diameter is a new biomarker for the evaluation of cardiovascular risk factors, limited information is available regarding the effects of endurance exercises on retinal microcirculation. Thus, we aimed to evaluate both chronic and acute effects of soccer game on the diameters of retinal vessels in middle-aged players., Methods: Retinal vessel diameters were measured in 12 middle-aged amateur players (44.4±7.0 years of age) with more than four years of soccer playing experience and 12 age-matched sedentary adults (49.7±7.1 years of age). In soccer players, diameters were also measured immediately after the soccer game. Cardiovascular risk profiles (anthropometry and body composition and blood pressure [BP]) and physical activity levels were also measured., Results: Soccer players had wider retinal vessels than controls (P<0.05), resulting in greater arteriolar-to-venular diameter ratio (AVR) (P<0.05). Greater sports-related physical activity, lower body mass index (BMI) and fat mass were observed for soccer players compared to the controls (P<0.05), whereas BP did not differ. Physical activity level correlated positively with temporal retinal arteriolar (TRA) diameter and with AVR (P<0.05), whereas TRA diameter correlated negatively with BMI and fat mass (P<0.05). A significant correlation between temporal retinal venule (TRV) diameter and TRA diameter (P<0.05) was observed. The acute soccer game increased BP (P<0.05) and induced TRV dilatation (P<0.05)., Conclusions: In middle-aged amateur soccer players, improvement of the retinal microcirculation was observed. Cardiovascular risk factors and physical inactivity were associated with adverse retinal microvascular alterations. In terms of acute effects, soccer play causes venular, but not arteriolar dilatation for middle-aged adults.

Venckunas, T, Snieckus, A, Trinkunas, E, Baranauskiene, N, Solianik, R, Juodsnukis, A, Streckis, V, and Kamandulis, S. Interval running training improves cognitive flexibility and aerobic power of young healthy adults. J Strength Cond Res 30(8): 2114-2121, 2016-The benefits of regular physical exercise may well extend beyond the reduction of chronic diseases risk and augmentation of working capacity, to many other aspects of human well-being, including improved cognitive functioning. Although the effects of moderate intensity continuous training on cognitive performance are relatively well studied, the benefits of interval training have not been investigated in this respect so far. The aim of the current study was to assess whether 7 weeks of interval running training is effective at improving both aerobic fitness and cognitive performance. For this purpose, 8 young dinghy sailors (6 boys and 2 girls) completed the interval running program with 200 m and 2,000 m running performance, cycling maximal oxygen uptake, and cognitive function was measured before and after the intervention. The control group consisted of healthy age-matched subjects (8 boys and 2 girls) who continued their active lifestyle and were tested in the same way as the experimental group, but did not complete any regular training. In the experimental group, 200 m and 2,000 m running performance and cycling maximal oxygen uptake increased together with improved results on cognitive flexibility tasks. No changes in the results of short-term and working memory tasks were observed in the experimental group, and no changes in any of the measured indices were evident in the controls. In conclusion, 7 weeks of interval running training improved running performance and cycling aerobic power, and were sufficient to improve the ability to adjust behavior to changing demands in young active individuals.

Background: Men have higher cold-induced neuroendocrine response than women; nevertheless, it is not known whether a different stress hormone rise elicits different effects on cognition during whole body cooling., Objective: The objective was to compare the effect of cold-induced neuroendocrine responses on the performance of working memory sensitive tasks between men and women., Materials and Methods: The cold stress continued until rectal temperature reached 35.5 degree C or for a maximum of 170 min. Working memory performance and stress hormone concentrations were monitored., Results: During cold stress, body temperature variables dropped in all subjects (P < 0.001) and did not differ between sexes. Cold stress raised plasma epinephrine and serum cortisol levels only in men (P < 0.05). Cold stress adversely affected memory performance in men but not in women (P < 0.05)., Conclusion: The present study indicated that similar moderate cold stress in men and women induces sex-specific neuroendocrine and working memory responses.