Chronic, acute and protocol-dependent effects of exercise on psycho-physiological health during long-term isolation and confinement.

Exercise could prevent physical and psychological deteriorations, especially during pandemic times of lock-down scenarios and social isolation. But to meet both, the common exercise protocols require optimization based on holistic investigations and with respect to underlying processes. This study aimed to explore individual chronic and acute effects of continuous and interval running exercise on physical and cognitive performance, mood, and affect and underlying neurophysiological factors during a terrestrial simulated space mission. Six volunteers (three females) were isolated for 120 days. Accompanying exercise training consisted of a continuous and interval running protocol in a cross-over design. Incremental stage tests on a treadmill were done frequently to test physical performance. Actigraphy was used to monitor physical activity level. Cognitive performance, mood (MoodMeter®), affect (PANAS), brain-derived neurotrophic factor (BDNF), insulin-like growth factor 1 (IGF-1), vascular-endothelial growth factor (VEGF), and saliva cortisol were investigated prior to, four times during, and after isolation, pre- and post-exercise on two separate days, respectively. As a chronic effect, physical performance increased (and IGF-1 tended) in the course of isolation and training until the end of isolation. Subjective mood and affect state, as well as cognitive performance, basal BDNF and VEGF levels, were well-preserved across the intervention. No acute effects of exercise were detected, besides slower reaction time after exercise in two out of nine cognitive tests, testing sensorimotor speed and memory of complex figures. Consistently higher basal IGF-1 concentrations and faster reaction time in the psychomotor vigilance test were found for the continuous compared to the interval running protocol. The results suggest that 120 days of isolation and confinement can be undergone without cognitive and mental deteriorations. Regular, individual aerobic running training supporting physical fitness is hypothesized to play an important role in this regard. Continuous running exercise seems to trigger higher IGF-1 levels and vigilance compared to interval running. Systematic and prolonged investigations and larger sample size are required to follow up on exercise-protocol specific differences in order to optimize the exercise intervention for long-term psycho-physiological health and well-being.

MSTN mRNA after varying exercise modalities in humans.

The aim of this study was to examine the effects of strength and endurance training on myostatin mRNA in the vastus lateralis muscle of healthy and physically active humans. 21 healthy and physically active sports students (static and dynamic knee extensor strength 33 ± 4.5 N/kgBW; 1 185 ± 170 W, respectively; maximum oxygen uptake 52.5 ± 8 ml/kgBW/min) were recruited and randomly assigned to a moderate endurance training group (n=7), a strength training group (n=7) and a control group (n=7). Muscle biopsies were taken from the vastus lateralis muscle 3-5 days before the start as well as at the end of the 12 weeks' training period. Exercise-specific functional improvements after moderate endurance training and strength training were measured for submaximal endurance and for static and dynamic strength of the knee extensor muscles. None of the myostatin mRNA values showed significant pre-post differences or group-specific differences. These results are in contrast to data with sedentary subjects, suggesting that myostatin is necessary for adaptations of skeletal muscle to exercise stress. We conclude that functional improvements after moderate endurance training and strength training can occur without alterations in myostatin mRNA in physically active humans.

Intense exercise increases adenosine concentrations in rat brain: implications for a homeostatic sleep drive.

Intense exercise and sleep deprivation affect the amount of homeostatically regulated slow wave sleep in the subsequent sleep period. Since brain energy metabolism plays a decisive role in the regulation of behavioral states, we determined the concentrations of nucleotides and nucleosides: phosphocreatine, creatine, ATP, ADP, AMP, adenosine, and inosine after moderate and exhaustive treadmill exercise as well as 3 and 5 h of sleep deprivation and sleep in the rat brain using the freeze-clamp technique. High intensity exercise resulted in a significant increase of the sleep-promoting substance adenosine. In contrast, following sleep, inosine and adenosine levels declined considerably, with an accompanied increase of ADP after 3 h and ATP after 5 h. Following 3 h and 5 h sleep deprivation, ADP and ATP did not differ significantly, whereas inosine increased during the 3 and 5-h period. The concentrations of AMP, creatine and phosphocreatine remained unchanged between experimental conditions. The present results are in agreement with findings from other authors and suggest that depletion of cerebral energy stores and accumulation of the sleep promoting substance adenosine after high intensity exercise may play a key role in homeostatic sleep regulation, and that sleep may play an essential role in replenishment of high-energy compounds.

Hypothalamic-pituitary-adrenal and -gonadal axis function after exercise in sedentary and endurance trained elderly males.

The aim of this study was to investigate hypothalamic-pituitary-adrenal (HPAA) and -gonadal (HPGA) axis responses to post-exercise (30 min at 65% VO2max) combined corticotrophin, luteinizing hormone and thyrotrophin releasing hormone challenge (0.7 microg/ kg body mass) in elderly distance runners (DR; age: 68.9+/-4.2 year) and sedentary individuals (SI; age: 69.1+/-2.6 year). Plasma cortisol, growth hormone, prolactin, luteinizing hormone, follicle stimulating hormone and total testosterone (T) concentrations pre- and post-exercise as well as in response to stimulation did not differ between DR and SI. Plasma adrenocorticotropic hormone returned to pre-exercise level in DR 60 min and in SI 90 min post-stimulation. Free T was lower in DR at all time points. Our results do not support the notion of altered releasing hormone-stimulable HPAA and HPGA synthesis-secretion capacity in elderly males after endurance training.