High-intensity interval and moderate-intensity continuous training ameliorate the deteriorating acute effect of noise stress on corticosterone and testosterone in rats.

PURPOSE: Noise has become an integral part of human life. Noise stress affect various physiological indices. In the present study, the effects of acute noise stress on corticosterone and testosterone and testosterone to cortisol ratio (T/C) in male rats, trained with two types of high-intensity interval training (HIIT) and moderate-intensity continuous training (MCT) were evaluated. METHODS: 42 male Wistar rats were divided randomly into seven groups, including the control group (C), control time (CT), exposure to acute noise stress (S), HIIT, MCT, HIIT with noise stress (HIIT + S), and MCT with noise stress (MCT + S). Exercise groups performed eight weeks of exercise training. One session of stress was induced in stress groups following the intervention (exercise or rest) period. Serum levels of corticosterone and T/C were measured through blood samples, taken 48 hours following the last session of exercise in the four exercise groups without noise stress and time control. Immediately after noise stress, blood samples were taken in 3 stress groups. RESULTS: Serum level of corticosterone in the MCT group was significantly higher than CT and HIIT groups (P = 0.001). Considering the effect of acute noise stress, corticosterone was significantly higher in HIIT + S and MCT + S, respectively, compared to the noise stress group (P < 0.001). Testosterone level of the noise stress group was significantly lower than CT group (P < 0.001). Testosterone level in the S group was significantly lower than other stress groups (MCT + S and HIIT + S) (P < 0.001). T/C in HIIT + S group was significantly higher compared to S and MCT + S groups (P < 0.001). CONCLUSION: HIIT and MCT, by priority, ameliorated the deteriorating effect of noise stress on testosterone and T/C; and it appears that the intensity and mode of previous exercise training affect the hormonal response to noise stress.

Maternal spatial training before fertilization improves the spatial learning process in female offspring.

Recent results of our team showed that parental spatial training before fertilization improves the offspring's spatial memory. However, the process of spatial learning (short-term/working and long-term memories, mnesic consolidation and procedures) in the offspring has not been fully clarified yet. Therefore, this study aimed at specifically analyzing whether maternal learning of a spatial task before fertilization can impact on the process of spatial learning in the female offspring. In the present study, 8-week-old female Wistar rats that had been spatially trained (or not) in the Morris Water Maze (MWM) were mated with conspecific standard-reared male rats, and their 4-week-old female offspring were spatially tested in the same MWM to evaluate their learning and memory processes. Results showed that the female offspring of trained mothers significantly displayed lower escape latencies, higher swimming speed, shorter total distance swum, longer percentage of time spent in the target quadrant and better localization memory in comparison to the female offspring of not trained mothers. Further, MWM performances of mothers trained and their female offspring significantly correlated. These findings indicate that the maternal spatial training before fertilization improves the spatial learning and memory consolidation process of the female offspring.

The Effect of Swimming on Anxiety-Like Behaviors and Corticosterone in Stressed and Unstressed Rats.

This study assessed the effect of swimming training on anxiety-like behaviors and corticosterone. Thirty adult male Wistar rats were randomly assigned to five study conditions: swimming training (ST); exposure to chronic mild stress (CS); exposure to chronic mild stress followed by swimming training (CS + ST); exposure to chronic mild stress followed by a recovery period (CS + recovery); control. The exercise training consisted of 60 min of swimming exercise per day, for five days a week, and four consecutive weeks. A chronic mild stress program (CMS) was applied for a period of four weeks. Anxiety-like behaviors were measured by open field test (OFT). The number of excrements and blood corticosterone were used as physiological parameters of anxiety. To assess corticosterone, blood samples were taken 48 h after the last session of experiments. Compared to other study conditions, the lowest anxiety-like behaviors and corticosterone concentrations were observed in the ST condition in unstressed rats. In stressed rats, as in the ST + CS group, swimming training probably reduced some anxiety behaviors, but the results showed increased corticosterone compared to control and CS + Recovery. Anxiety parameters and corticosterone concentrations were greatest in the CS condition. In the ST group, anxiety parameters were less than for the ST + CS group. In the CS + Recovery group, anxiety parameters were less than for the CS group. In summary, self-paced swimming training could attenuate some anxiety parameters in both stressed and non-stressed rats. The effect of swimming training in unstressed rats was more prominent than in stressed rats. In stressed rats, a period of recovery was more effective than swimming training in reducing corticosterone. Mechanisms of anxiety reduction other than cortisol should be investigated in future research.

Association between physical activity, cardiorespiratory fitness, and body composition with menopausal symptoms in early postmenopausal women.

OBJECTIVE: The aim of this study was to investigate the relationship between daily physical activity (daily activities, exercise, and sitting time), cardiorespiratory fitness (CRF), and body composition (body mass index [BMI], waist to hip ratio [WHR)] with menopausal symptoms and to determine the strongest predictor(s) of menopausal symptoms. METHODS: The Menopause Rating Scale questionnaire was used to examine somatic, psychological, urogenital, and total symptoms of menopause. The energy expenditure of daily physical activity, exercise, and sitting time was measured by the International Physical Activity Questionnaire, and CRF was measured by estimating the maximal oxygen intake (VO2max) through the Rockport test. Statistical methods of the Pearson correlation coefficient and hierarchical multiple linear regression were used for data analysis. RESULTS: Fifty-six women, aged 50 to 65 years, voluntarily participated in the study. Exercise energy expenditure was inversely correlated with total (r = -0.403, P = 0.002), somatic (r = -0.293, P = 0.023), and urogenital (r = -0.343, P = 0.009) symptoms of menopause. VO2max was inversely correlated with urogenital symptoms of menopause (r = -0.414, P = 0.002). WHR was positively correlated with somatic symptoms of menopause (r = 0.286, P = 0.032); sitting was correlated with total (r = 0.40, P = 0.002), somatic (r = 0.325, P = 0.015), and psychological (r = 0.274, P = 0.015) symptoms of menopause. Among the study variables, sitting (ß=0.365, P = 0.004) and VO2max (ß=-0.286, P = 0.030) were the most important predictors of total symptoms of menopause; sitting was the predictor of somatic symptoms (ß=0.265, P = 0.045), and VO2max was the predictor of urogenital symptoms of menopause (ß=-0.332, P = 0.014). The inclusion of age, BMI, WHR, and duration of menopause as confounding variables in regression analysis did not change the findings related to the predictions of menopausal symptoms. CONCLUSION: Reducing sitting time, improving VO2max, decreasing WHR, and exercise can be recommended by priority to alleviate menopausal symptoms. Considering the small number of participants in this investigation, future studies are, however, recommended.

High intensity exercise preconditioning provides differential protection against brain injury following experimental stroke.

AIMS: Different modes of physical activity provide cerebrovascular protection against thromboembolic events. Based on recent reports high intensity exercise protocols appear to raise cerebral VEGF levels leading to efficient cerebral angiogenesis. The present study aims to address if moderate continuous training (MCT) and high intensity interval training (HIT) differ in preconditioning against ischemic stroke. METHODS: Wistar rats were subjected to HIT or MCT for 8 weeks before transient middle cerebral artery occlusion (tMCAO) surgery. As indexes for improved angiogenic signals, VEGF-A and its pivotal receptor VEGF-R2 were immunoblotted just before occlusive stroke. KEY FINDINGS: Both training protocols induced a remarkable protection against neurological deficit and tissue injury following stroke. Cerebral infarctions were better improved in HIT animals which explained the slightly but not significantly higher neurological function. HIT brains developed higher levels of cortical VEGF-A and striatal VEGF-R2. SIGNIFICANCE: These data conclude preconditioning with high intensity protocols might excel continued moderate exercise to induce VEGF signaling and alleviate stroke outcomes. Further investigations may provide complementary mechanistic views.

Differential impact of treadmill training on stroke-induced neurological disorders.

OBJECTIVE: Physical exercise contributes to improving stability against nerve injury caused by ischaemic stroke. Here we aimed to preliminarily investigate the effects of continuous endurance training (CET) and high-intensity interval training (HIT) on stroke-associated anxiety, locomotion, neurological assessments and P70S6 Kinase (P70S6K) activation as well. To do this, rats were trained according to HIT and CET protocols for 2 months prior to being subject to middle cerebral artery occlusion surgery. METHODS: Twenty-four hours later behavioural examination was performed by elevated plus maze (EPM) testing, open field and neurological scoring followed by cortical and hippocampal P70S6Ks immunoblotting. RESULTS: According to the obtained data pre-ischaemic HIT and CET similarly improved neurological performance, anxiety levels and locomotion in EPM and open field tests following ischaemic stroke while there was a remarkable rise in hippocampal and cortical P70S6K activation in the HIT group compared to the CET counterparts. CONCLUSION: Behavioral and molecular data suggest that interval training is more beneficial rather than CET, but the distinct mechanisms of CET and HIT on memory are still topics to be discovered.