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. Estrogen levels were also measured in the female participants during the 48-h fast.

RESULTS

Glucose area under the curve (AUC) values increased similarly in both sexes after 48-h fasting (P < 0.05), but females displayed a greater rise in insulin AUC values than males (P < 0.05). Fasting increased plasma epinephrine concentrations in both sexes (P < 0.05), whereas plasma norepinephrine concentrations and subjective stress increased only in females (P < 0.05). Plasma 17-β-estradiol concentrations in females decreased after fasting (P < 0.05).

CONCLUSION

Fasting for 48 h induced a similar glucose intolerance in females and males, despite decreased 17-β-estradiol levels and greater psychological and physiological stress in females. These differences represent a plausible explanation for the gender-based differences observed in insulin responses.

TRIAL REGISTRATION

Retrospectively registered on ClinicalTrials.gov (NCT05545943) in September 19, 2022.

Short-duration cold exposure decreases fasting-induced glucose intolerance but has no effect on resting energy expenditure

The aim of the present study was to investigate whether brief cold exposure can reverse fasting-induced glucose intolerance and insulin resistance, and improve resting energy expenditure (REE). Twelve young non-obese women were randomly assigned to undergo the following conditions: 2 days of fasting with two 10-min whole-body cold-water immersions on separate days (FAST-COLD), 2 days of fasting without cold-water immersions (FAST), 2 days of usual diet with two 10-min whole-body cold-water immersions on separate days (COLD), or 2 days of usual diet without cold-water immersions (CON) in a randomised crossover fashion. Changes in REE and substrate utilisation, and glucose tolerance and insulin sensitivity from the oral glucose tolerance test were examined. The results showed that FAST-COLD and FAST trials increased (P < 0.05) REE and decreased (P < 0.05) respiratory quotient, but these variables did not differ significantly between the FAST-COLD and FAST trials. The glucose and insulin area under the curves (AUCs) were higher (P < 0.05) in the FAST-COLD and FAST trials than in the CON and COLD trials, and these AUCs were lower (P < 0.05) in the FAST-COLD than in the FAST trial. Matsuda index was lower in the FAST trial than in the CON trial (P < 0.05), and tended to be greater after the FAST-COLD trial than after the FAST trial (P = 0.060). In conclusion, cold exposure had no effect on REE but decreased fasting-induced glucose intolerance which was accompanied by a maintained insulin sensitivity.

Prolonged fasting outperforms short-term fasting in terms of glucose tolerance and insulin release: a randomised controlled trial

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.

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

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.

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.

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.

Four-Week Application of Kinesiotaping Improves Proprioception, Strength, and Balance in Individuals With Complete Anterior Cruciate Ligament Rupture

ABSTRACT

Kielė, D and Solianik, R. Four-week application of kinesiotaping improves proprioception, strength, and balance in individuals with complete anterior cruciate ligament rupture. J Strength Cond Res 37(1): 213-219, 2023-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.

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.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.

The Effects of the Nirvana Fitness Exercise Programme on Perceived Stress and Cognition

Background. Mind and body exercise programmes, such as Tai Chi, Yoga and Pilates, can be successfully applied for stress reduction and cognitive function enhancement, however Nirvana Fitness training effects on perceived stress and cognition remain equivocal. The aim. To determine the effects of Nirvana Fitness training on perceived stress and cognition. Methods. The study included 20 women. They were randomly assigned to a control (n=10) or experimental (n=10) group. Participants in the experimental group participated in the Nirvana Fitness exercise programme, which consisted of a 50-minute class twice a week for 8 weeks. Participants in the control group were asked to maintain their daily routines. Changes in perceived stress and cognitive performance were evaluated. Results. The Nirvana Fitness exercise programme significantly decreased (p<0.05) perceived stress and improved (p<0.05) inhibitory control and cognitive flexibility, whereas spatial and working memory remained unchanged. Conclusion. The Nirvana Fitness programme can be used as an effective method to decrease stress and improve attention in women. Keywords: memory, attention, women, mind and body exercise programmes  

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

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.

Two-day fasting affects kynurenine pathway with additional modulation of short-term whole-body cooling: a quasi-randomised crossover trial

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, ηp2 = 0·24), and increased concentrations of KYNA, 3-HK and PIC (P < 0·05, ηp2 = 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 (ηp2 = 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.

Exposure to acute noxious heat evokes a cardiorespiratory shock response in humans

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.

Tai chi effects on balance in older adults: the role of sustained attention and myokines

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 actor 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.

Residual effects of short-term whole-body cold-water immersion on the cytokine profile, white blood cell count, and blood markers of stress

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.

Tai chi improves psychoemotional state, cognition, and motor learning in older adults during the COVID-19 pandemic

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.

Acute effects of high-intensity interval training on cognition and retinal microcirculation in experienced amateur boxers

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.

The Effect of Aerobic Exercise with Calorie Restriction Program on Muscle Strength and Aerobic Capacity in Overweight and Obese Women

Background. Few studies have demonstrated that different combinations of calorie restriction (CR) and aerobic exercise training improved aerobic capacity (Redman et al., 2007; Weiss et al., 2017) but did not change muscle strength (Weiss et al., 2017) in adult overweight subjects. However, the effect of six-month program combined of moderate intensity aerobic exercise (150 min/week) and 12.5% of CR on aerobic capacity and muscle strength remains unclear.The aim of the present study was to estimate the effect of a six-month aerobic exercise with CR program on muscle strength and aerobic capacity in middle-aged, overweight and obese women.Methods. Twenty-six overweight and obese sedentary women (36–56 years of age, body mass index (BMI) 25.0–37.5 kg/m2) were recruited and randomly allocated to either control or experimental aerobic exercise with CR program group for six-month period. Changes in handgrip strength, knee extension and flexion strength and aerobic capacity (VO2peak) were measured.Results. Absolute peak VO2 (P < 0.001) and normalized peak VO2 (P = 0.013) significantly increased after the aerobic exercise with CR program. A greater normalized peak VO2 (P < 0.001) was observed after the aerobic exercise and CR intervention compared with the control group. However, no effect was estimated on muscle strength in this study.Conclusions. The combined 6-month aerobic exercise with CR program improved the aerobic capacity in middle-aged, overweight and obese women, but had no effect on isometric and isokinetic strength.Keywords: diet; physical exercise; obesity; muscle; cardiovascular fitness.

Yoga Practice Improves Physical Fitness and Psychomotor Coordination in Older Adults

Background. There is evidence that yoga practice can improve cardiovascular endurance, and that physically fit individuals have better psychomotor functioning, however, to the best of our knowledge, no information is available regarding yoga effects in population aged 60 years and older. The aim of the study was to test the hypothesis that 10 weeks of yoga practice would improvephysical fitness and psychomotor coordination in older adults.Methods. Thirty-three older adults aged 66.9 ± 6.0 years were randomly assigned to the control group and the experimental group, which had 90-min yoga practice twice a week, for 10 weeks. Attendance and adherence ratios, and changes in cardiovascular endurance, flexibility, grip strength, and psychomotor coordination were assessed. Results. Attendance of the experimental group subjects in yoga practice was 96.4 ± 4.1%. Yoga practice increased (p < 0.05) hand grip strength, flexibility in hips, thighs and spine, and decreased (p < 0.05) the distance from target in the psychomotor task, whereas no changes in peak oxygen consumption were observed.Conclusion. Nevertheless, regular 10-week yoga practice had no effect on cardiovascular endurance, but it produced beneficial changes in muscular strength, flexibility and psychomotor coordination for older adults.Keywords: aging, cardiovascular endurance, strength, flexibility, exercise.

Effects of Aerobic Exercise on Cognitive Function and Affected Arm Function in Individuals with Ischemic Stroke

Background. Aerobic exercise has been successfully applied for cognitive and motor function improvement; however, its effects on the affected arm function in individuals with stroke remains equivocal.Research aim. The aim of this study was to determine the effects of aerobic exercise on cognitive function and affected arm function in individuals with ischemic stroke.Methods. The study included 16 subjects with ischemic stroke. They were randomly assigned to control (30 min of usual physiotherapy) and experimental (30 min of usual physiotherapy plus 20 min of aerobic exercise) groups. The interventions were performed five times a week, for 8 weeks. Cognitive performance and the affected arm function were evaluated before and after interventions.Results. In the experimental group, improvement (p < 0.05) in the affected arm function and attention were observed. Both interventions significantly improved (p < 0.05) cognitive flexibility; however, greater improvement (p < 0.05) was observed after experimental intervention compared with control intervention. No differences in intervention effects on working memory were observed.Conclusions. Aerobic exercise, which is performed immediately after physiotherapy, improves recovery of impaired arm function, attention, and cognitive flexibility in individuals with ischemic stroke.Keywords: endurance exercises, motor function, aerobic exercise, cognitive flexibility.

Effect of Dual Task Training on Balance and Functional Mobility in Children with Cerebral Palsy

Research background. It was found that dual task training improves functional abilities in subjects with neurological disorders, however it is not known how dual task training affects balance and functional mobility in children with cerebral palsy (CP).The aim. To determine the effectiveness of dual motor tasks training and basic physiotherapy programme on balance and functional mobility in children with spastic diplegic CP.Methods. The study included 20 children with spastic diplegic CP. Subjects were randomly assigned into two groups: control group (40 min basic physiotherapy programme) and experimental group (20 min basic physiotherapy programme and 20 min dual motor task training). Physiotherapy was applied for 3 weeks (5 times a week). Balance and functional mobility were assessed at baseline and at the end.Results. There was a statistically significant improvement in balance and functional mobility in both the control and experimental groups after three weeks of physiotherapy (p < 0.05). Comparing two groups with each other, there was a statistically significant improvement in the experimental group on balance and walking (p < 0.05).Conclusion. Dual task training can be used as an effective intervention to improve balance and walking in children with spastic diplegic CP.Keywords: motor tasks, cerebral palsy, balance, functional mobility.

Forty-eight-hour fasting declines mental flexibility but improves balance in overweight and obese older women

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.

Aerobinių pratimų ir kalorijų apribojimo poveikis nutukusių ir antsvorį turinčių moterų ramybės medžiagų apykaitai, substratų oksidacijai ir metabolinio sindromo rodikliams

Tyrimo pagrindimas. Nors yra keletas tyrimų, nagrinėjančių skirtingų mitybos režimų ir fizinių pratimų programų kombinacijų įtaką svorio mažinimui ir su tuo susijusiam poveikiui sveikatai, vis dar neaišku, kaip šiuos rodiklius veikia šešių mėnesių 12,5% kalorijų apribojimo ir 150 minučių vidutinio intensyvumo aerobinių pratimų per savaitę Tyrimo tikslas buvo patikrinti hipotezę, kad šešių mėnesių kalorijų apribojimo ir aerobinių pratimų intervencija padidins medžiagų apykaitą ramybėje ir riebalų oksidaciją, pagerins antropometrinius ir metabolinius Metodai. Nutukusios ir antsvorį turinčios tiriamosios (amžius 44.2 ± 7.2 m.) buvo atsitiktinai suskirstytos į kontrolinę (n = 13) ir eksperimentinę (pastarajai buvo taikyta kalorijų apribojimo ir aerobinių pratimų intervencija, trukusi 6 mėnesius) grupes (n = 13). Buvo išmatuoti ramybės medžiagų apykaitos, substratų oksidacijos, kūno masės indekso, liemens apimties, kraujo spaudimo, lipidų ir gliukozės Rezultatai.  Ramybės medžiagų apykaita padidėjo (p < 0.05) eksperimentinėje grupėje, o substratų oksidacijos pokyčių nenustatyta. Po kombinuotos kalorijų apribojimo ir pratimų intervencijos sumažėjo (p < 0.05) kūno masės indeksas, liemens apimtis, sistolinis kraujo spaudimas, trigliceridų ir gliukozės koncentracija, padidėjo (p < 0.05) didelio tankio lipoproteinų cholesterolio Išvados. Šešis mėnesius taikoma kalorijų apribojimo 12,5% ir 150 minučių vidutinio intensyvumo aerobinių pratimų per savaitę programa yra susijusi su veiksminga ir sveika svorio mažinimo strategija, kuri gali apsaugoti moteris nuo metabolinio sindromo ir pagerinti ramybės medžiagų apykaitą.Raktažodžiai: nutukimas, moterys, aerobinė treniruotė, sveikata.

Changes in Gait Kinematic Parameters after Severe Traumatic Brain Injury during Post-Acute Rehabilitation

Changes in gait after traumatic brain injury (TBI) are very important for evaluation, clinical reasoning and forintervention programs. Most studies analyze gait during acute phase, but there is lack of information during post-acute period. The aim of the research was to determine gait biomechanical joint angles and centre of mass displacement changes during post-acute TBI rehabilitation. Participant was a 21-year-old male, after severe TBI, 2 years after trauma. Biomechanical joints angles and centre of mass displacement changes were observed during 3D gait analysis. The subject was asked to walk straight 6 meters, 18 times at his preferred comfortable pace. During walking 1–2 minute breaks were made. Intensive 5 week program was composed of physiotherapy (3 times per week) and yoga (2 times per week). Physiotherapy included stretching, coordination, balance and weight-bearing exercises. Yoga was performed to built core stability, train flexibility and diminish muscle tone. After 5 week rehabilitation statistically significant changes were observed in the centre of mass displacement and in lower extremities and lumbar biomechanics (p < 0.05). After procedures trunk flexion and trunk lateral flexion, lateral pelvic tilt increased, while anterior pelvic tilt decreased (p < 0.05). Hip extension at terminal stance increased, as well while hip adduction in stance phase decreased (p < 0.05). Statistically significant reduction was observed in knee flexion at initial contact, mid-stance and midswing phase (p < 0.05). Prevalent knee flexion at initial contact, observed before rehabilitation, decreased after it (p < 0.05). After the procedure lateral centre of mass displacement decreased and vertical centre of mass displacement increased (p < 0.05). Five weeks of rehabilitation composed of traditional physiotherapy and yoga is effective for gait quality treatment. However, further research is necessary to determine gait biomechanical joint angles and dynamic balance improvements during severe post-acute TBI.Keywords: head injury, walking, balance.

Balance Alterations Before ACL Surgery and After Rehabilitation

Knee anterior cruciate ligament (ACL) is one of the most often injured knee anatomical structures. There are few studies about balance after ACL rupture, but all results are controversial [1, 2, 3]. Our primary aim was to determine the static and dynamic balance changes before ACL surgery and after rehabilitation. Goals of the study: 1) to investigate and to compare static balance before ACL surgery and after rehabilitation; 2) to investigate and to compare dynamic balance before ACL surgery and after rehabilitation. Ten untrained males participated in this study after ACL rupture (mean ± SD, age 28.4 ± 8.1 years, height – 179.8 ± 8.5 cm, weight – 76.0 ± 14.0 kg). The study was performed in the Lithuanian Academy of Physical Education in the Sports and Movements Science Centre. All subjects where tested before ACL surgery and after 3 months of rehabilitation. Two weeks after the surgery the following rehabilitation was applied: physiotherapy, massage and physiotherapy in the water (3 times per week, 16 times in total). Following these procedures rehabilitation was continued with muscle strength training exercises in a gym. Balance was measured when participant stood on a KISTLER balance platform with open eyes, looking directly into the selected point 2 m away at the eye level, hands on hips. Balance within 20 s while standing on one leg and balance within 15 s after one leg hop for both healthy and ACL ruptured legs were measured. The results showed that standing on ACL ruptured leg before surgery and after rehabilitation the oscillations were not significantly different, but standing on the healthy leg after rehabilitation significantly improved. Test results after one leg hop on ACL ruptured leg showed that oscillations were significantly greater after rehabilitation. Conclusions: 1. After rehabilitation one leg static balance improved only in non-injured leg. 2. After rehabilitation one leg dynamic balance decreased in injured leg, but increased in non-injured leg.Keywords: anterior cruciate ligament, rehabilitation, static balance, dynamic balance

Impact of Physiotherapy on the Calf Muscle Torque Variability after Achilles Tendon Rupture

It has been established that muscle torque variability determines movement stability during the task [1]. Calf muscle weakness, ankle range of motion reduction and postural misbalance are common pathological limitations after Achilles tendon rupture (ATR). Most studies analyse rehabilitation influence for muscle strength and body balance, but there is a lack of information about calf muscle torque variability. The aim of the study was to determine ankle plantar flexion and dorsal flexion muscle maximal voluntary contraction torque and variability Q. Organization and methods. We measured five males, (aged 29 ± 6) after 6.5 – week surgery of ATR. Participants performed isometric ankle flexion and extension force with injured and non-injured legs. Muscles maximal voluntary contraction (MVC) torque and torque variability were measured at –15°; 0°; 15° angles. The variability of target force was 20% of MVC torque. Rehabilitation programme consisted of balance, muscle strength and stretching exercises. Calf muscle MVC torque and variability were observed before and after 8-week rehabilitation. The results of the research. We determined that after physiotherapy the injured and the non-injured leg isometric ankle flexion and extension muscle MVC torque increased and muscle torque variability decreased.Keywords: muscle torque variability, isometric maximal voluntary contraction torque, rehabilitation suformavimas.

Action Observation Therapy Improves Gait, but does Not Affect Balance in Older Adults

 Research background. Action observation therapy has been successfully applied in treatment of gait and balance problems in neurological patients, however its effects on gait and balance in older adults remains equivocal. Research aim. The aim of this study was to determine the effects of action observation therapy on gait and balance in older adults. Research methods. The study included 20 older adults. They were randomly assigned to control (usual physiotherapy plus nature recordings observation) and intervention (usual physiotherapy plus action recordings observation) groups. The interventions consisted of a 60-min program fve times a week, for 8 weeks. Gait and balance were evaluated before and after interventions. Research results. Both interventions signifcantly improved (p < 0.05) gait and balance. Greater gait improvement (p < 0.05) was observed after usual therapy plus action recordings observation compared with usual therapy plus nature recordings observation, whereas no differences in intervention effects on balance were observed. Conclusions. Action observation therapy can be used as an effective intervention to improve gait in older adults, whereas it has no effect on balance.Keywords: action observation, motor function, elderly, mirror neurons.

Effects of Tai Chi On Cognitive Functions and Motor Learning in Persons with Multiple Sclerosis

Research background. The existing evidence supports the effectiveness of Tai Chi for persons with multiple sclerosis (MS) in various domains including depression, coordination, balance, and fatigue. However, we are not aware of any previous studies of the effects of Tai Chi on cognition and motor skill learning in persons with MS. The aim of this study was to determine the effects of Tai Chi on cognitive functions and motor learning in persons with multiple sclerosis. Methods. The study included 16 participants with MS. They were randomly assigned to intervention (n = 8) and control (n = 8) groups. The intervention consisted of a 60-min Tai Chi exercise program twice a week, for 8 weeks, while the control group was instructed to maintain their routine daily activities. Cognitive functions and learning of accurate movements were evaluated before and after the 8 weeks in each group. Results. Tai Chi exercise program improved (p < 0.05) working memory and attention switching, whereas no changes were observed in short-term memory and attention stability in persons with multiple sclerosis. Furthermore, Tai Chi facilitated (p < 0.05) motor learning when compared with the control group. Conclusions. Tai Chi can be used as an effective intervention to improve cognitive functions, such as working memory and predictable attention switching, and motor skill learning in persons with multiple sclerosis. Keywords: working memory, attention switching, meditation, motor skills.Keywords: working memory, attention switching, meditation, motor skills.

Acute and chronic effects of soccer game on the retinal vessel diameters in middle-aged adults

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.

Prefrontal Cortex Activity Predicts Mental Fatigue in Young and Elderly Men During a 2 h "Go/NoGo" Task

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.

Effects of age and sex on fatigability and recovery from a sustained maximal isometric voluntary contraction

The aim was to assess the effects of sex and age on fatigability and recovery from sustained maximal voluntary contraction (MVC) of the knee extensor muscles. The central (central activation ratio (CAR) and electrical activity amplitude) and peripheral (electrically evoked torque and muscle contractile properties) factors contributing to fatigue and recovery of 24 young adults (12 males) aged 23.2±3.6years and 20 older adults (12 males) aged 70.6±4.4years were compared. The increase in central and peripheral fatigue was greater (p⩽0.01) in the young adults vs the older adults. Sex differences (p=0.002) regarding MVC were attributed to the greater (p<0.01) peripheral fatigue of males vs females. The recovery rate of MVC was greater (p<0.001) in the young adults vs the older adults, with no sex effect. The recovery of MVC was correlated with the CAR in older adults (p=0.001). Thus, the greater endurance observed with age is caused by differences in central and peripheral mechanisms, whereas the greater endurance in females is caused by a difference in a mechanism located within the muscle. The impaired recovery from fatigue in older adults relied more on the recovery of central factors.

Interval Running Training Improves Cognitive Flexibility and Aerobic Power of Young Healthy 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.

Similar cold stress induces sex-specific neuroendocrine and working memory responses

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.