High-intensity interval training mitigates the progression of periodontitis and improves behavioural aspects in rats.

AIM: To investigate the effects of high-intensity interval training (HIIT) on periodontitis (PD) progression and behavioural outcomes. MATERIALS AND METHODS: Forty-eight Wistar rats were divided into four groups: non-trained (NT); non-trained with PD; HIIT with PD; and HIIT. The HIIT protocol, involving daily treadmill sessions, spanned 8 weeks, with PD induced by ligature after the 6th week. Behavioural tests were conducted to assess anxiety and memory. Post euthanasia, we evaluated the systemic inflammatory profile and oxidative stress markers in the hippocampus and amygdala. A morphological evaluation and elemental composition analysis of the mandibular alveolar bone were performed. RESULTS: PD exacerbated alveolar bone level, bone surface damage and alterations in calcium and phosphorus percentages on the bone surface (p < .05), while HIIT attenuated these changes (p < .05). HIIT improved systemic inflammatory markers altered by PD (tumour necrosis factor [TNF]-α, interleukin [IL]-10, TNF-α/IL-10 and IL-1ß/IL-10 ratios, p < .05). PD animals exhibited lower total antioxidant capacity and levels of thiobarbituric acid reactive substances in the amygdala and hippocampus, respectively (p < .05). HIIT maintained these parameters at levels similar to those in NT animals. HIIT improved anxiety and memory outcomes altered by PD (p < .05). CONCLUSIONS: HIIT attenuates systemic inflammation, anxiety and memory outcomes promoted by PD.

Middle cerebral artery blood velocity and cognitive function after high- and moderate-intensity aerobic exercise sessions.

This crossover study explored the acute effect of a session of high-intensity interval training (HIIT) or moderate-intensity continuous training (MICT) on middle cerebral artery (MCA) variables such as cerebral blood velocity, pulsatility index (PI) and resistivity index (RI) through transcranial Doppler (TCD), and cognitive function (CF - verbal fluency and Digit Span) in healthy young adults. Participants (26 healthy young adults, 13 women, 24 ± 3 years) underwent two different randomized exercise sessions: (1) MICT (60 % heart rate reserve, HRR) and (2) HIIT (80 % HRR). MCA velocity, PI, RI, CF, and serum lactate were measured immediately before and after the sessions. HIIT demonstrated improved executive function/semantic fluency (20 %, p = 0.019), while both MICT and HIIT increased lactate (625 %, HIIT, p < 0.001, and 238 %, MICT, p < 0.001). Other assessments remained stable, except for reduced PI (p = 0.029) and RI (p = 0.023) after MICT, with no significant difference (pre-post for HIIT-MICT). Notably, cognition improvement correlated with lactate increase in HIIT (ρ = 0.436; p < 0.001). Executive function/semantic fluency increased after HIIT relative to MICT. The findings show that there are no systematic out-of-normal changes in the cerebrovascular circulation of clinically healthy adults undergoing HIIT and MICT.

Intense Caloric Restriction from Birth Prevents Cardiovascular Aging in Rats.

We previously demonstrated that a 50% caloric restriction (CR) from birth improves several cardiometabolic risk factors in young rats. In this study, we investigated in middle-aged rats the consequences of a 50% CR from birth on cardiometabolic risk factors, heart function/morphology, ventricular arrhythmia, and fibrillation incidence, and cardiac intracellular proteins involved with redox status and cell survival. From birth to the age of 18 months, rats were divided into an Ad Libitum (AL18) group, which had free access to food, and a CR18 group, which had food limited to 50% of that consumed by the AL18. Resting metabolic rate, blood pressure, and heart rate were recorded, and oral glucose and intraperitoneal insulin tolerance tests were performed. Blood was collected for biochemical analyses, and visceral fat and liver were harvested and weighed. Hearts were harvested for cardiac function, histological, redox status, and western blot analyses. The 50% CR from birth potentially reduced several cardiometabolic risk factors in 18-month-old rats. Moreover, compared with AL18, the CR18 group showed a ∼50% increase in cardiac contractility and relaxation, nearly three to five times less incidence of ventricular arrhythmia and fibrillation, ∼18% lower cardiomyocyte diameter, and ∼60% lower cardiac fibrosis. CR18 hearts also improved biomarkers of antioxidant defense and cell survival. Collectively, these results reveal several metabolic and cardiac antiaging effects of a 50% CR from birth in middle-aged rats.

Superior cardiometabolic and cellular adaptive responses to multiple versus single daily sessions of high-intensity interval training in Wistar rats.

This study aimed to compare in rats the cardiometabolic and cellular adaptative responses to 8 weeks of high-intensity interval training (HIIT) performed in a single (1xHIIT) or three shorter daily sessions (3xHIIT). Male Wistar rats were assigned to untrained (n = 10), 1xHIIT (n = 10), and 3xHIIT (n = 10) groups. Both HIIT groups performed 15 min of a treadmill run five times per week for 8 weeks. The 1xHIIT performed single daily sessions of 15 min, and the 3xHIIT performed three daily sessions of 5 min with an interval of 4 h between sessions. Resting VO2 and VO2max were measured using a metabolic chamber; blood pressure and heart rate were measured by plethysmography; body composition was estimated by DEXA; Glucose and insulin tolerance tests were performed; after euthanasia, hearts, gastrocnemius, and visceral fat were harvested for analysis of cardiac function, histology, and morphology. Mitochondrial densities of the gastrocnemius and left ventricle muscles were determined by electron microscopy. 3xHIIT induced similar positive adaptative responses to 1xHIIT on resting VO2 and VO2max, cardiac function, and mitochondria density. 3xHIIT was superior to 1xHIIT in reducing visceral fat weight and adipocyte size and improving insulin tolerance. Multiple short daily bouts of HIIT may be superior to single HIIT daily sessions in improving cardiometabolic and cellular adaptations in rats.

Effects of the association of different volumes of strength training with photobiomodulation therapy on insulin resistance: A protocol for a randomized, triple-blind, placebo-controlled trial.

Background: Insulin resistance (IR) is the main risk factor for developing type 2 diabetes. Both strength training (ST) and photobiomodulation therapy (PBMt) reduce IR, but the effect of combining different volumes of ST with PBMt is unknown. Methods: Overweight/obese individuals will be assigned to 4 groups (n = 12/group): ST with volume following international guidelines (3 sets per exercise - high volume) or one-third of this volume (1 set per exercise - low volume), combined with PBMt or placebo. ST will be performed for 20 sessions over 10 weeks and will consist of 7 exercises. The PBMt will be applied after training sessions using blankets with light emitters (LEDs) placed over the skin on the frontal and the posterior region of the body, following the parameters recommended by the literature. The placebo group will undergo an identical procedure, but blankets will emit insignificant light. To measure plasma glucose and insulin concentrations, oral glucose tolerance tests (OGTT) will be performed before and after the training period. Thereafter, IR, the area under the curve of glucose and insulin, and OGTT-derived indices of insulin sensitivity/resistance will be calculated. Expected impact on the field: This study will determine the effects of different ST volumes on IR and whether the addition of PBMt potentiates the effects of ST. Because previously sedentary, obese, insulin-resistant individuals might not comply with recommended volumes of exercise, the possibility that adding PBMt to low-volume ST enhances ST effects on IR bears practical significance.

Alzheimer's disease genes and proteins associated with resistance and aerobic training: An in silico analysis.

BACKGROUND: Exercise appears to be a viable intervention for maintaining cognitive function and regaining functional autonomy, and perhaps even contributing to a slower progression of Alzheimer's Disease (AD). OBJECTIVE: To explore different neuroplasticity pathways modulated by aerobic and strength training, determine whether signaling pathways overlapped for each specific training method (aerobic and strength training), and evaluate whether there is a functional relationship between APOE and APP gene expression with aerobic training modulated by BDNF; and strength training modulated by IGF-1. METHODS: An in silico analysis was performed to analyze the connection between exercise types and neuroplasticity as a protective factor in AD. The platform provides a protein-protein interaction network translated into known and predicted interactions. A score > 0.70 was determined as high confidence and the network was considered significant when the Protein-Protein Interaction Enrichment was <0.01. RESULTS: Multiple functional associations considered significant between the analyzed proteins. The results of our gene network model support that exercise, both aerobic and strength, can modulate genes that affect hippocampal neuroplasticity and neurogenesis, which may delay cognitive decline and Alzheimer's related symptoms. CONCLUSION: The investigation about the functional association of aerobic training via BDNF in the modulation of APP, APOE, and MAPT genes in the hippocampus seems to be established, while strength training seems to induce the production of IGF-1 and IGF-1R, modulating AKT1.

A Real-World High-Intensity Interval Training Protocol for Cardiorespiratory Fitness Improvement.

High-Intensity Interval Training (HIIT) has emerged as an interesting time-efficient approach to increase exercise adherence and improve health. However, few studies have tested the efficiency of HIIT protocols in a "real world" setting, e.g., HIIT protocols designed for outdoor spaces without specialized equipment. This study presents a "real world" training protocol, named "beep training", and compares the efficiency of a HIIT regiment versus a traditional long-duration Moderate-Intensity Continuous Training (MICT) regiment using this beep training protocol on VO2 max of overweight untrained men. Twenty-two subjects performed outdoor running with MICT (n = 11) or HIIT (n = 11). Cardiorespiratory fitness was assessed before and after training protocols using a metabolic analyzer. Both training protocols were performed 3 days a week for 8 weeks using the Beep Test results. The MICT group performed the exercise program at 60%-75% of the maximum speed of the 20 m shuttle test (Vmax) and with a progression of the distance of 3,500-5,000 m. The HIIT group performed the interval exercise with 7-10 bouts of 200 m at 85%-100% of the maximum speed of the 20 m shuttle test (Vmax), interspersed with 1 min of passive recovery. Although the HIIT group presented a significantly lower training volume than the MICT group (p < 0.05) after 8 weeks of beep training, HIIT was superior to MICT in improving VO2 max (MICT: ~4.1%; HIIT: ~7.3%; p < 0.05). The "real world" HIIT regiment based on beep training protocol is a time-efficient, low-cost, and easy-to-implement protocol for overweight untrained men.

Accumulated High-intensity Interval Training Protocol: A New Approach to Study Health Markers in Wistar Rats.

High-Intensity Interval Training (HIIT) and accumulated exercises are two time-efficient programs to improve health in humans and animal models. However, to date, there are no studies on whether HIIT performed in an accumulated fashion is as effective as a traditional HIIT performed with single daily sessions in improving health markers. This paper presents the effects of a new HIIT protocol, called accumulated HIIT, on body weight gain, maximal oxygen consumption (VO2max), and cardiac hypertrophy in young Wistar rats. Sixty-day-old male Wistar rats were assigned to three groups: untrained (UN; n = 16), HIIT performed with single daily sessions (1-HIIT; n = 16), and HIIT performed with three daily sessions (3-HIIT; n = 16). Body weight and VO2max were recorded before and after the training period. The VO2max measurements were taken using a metabolic analyzer at the maximal running velocity (Vmax). The training was performed for both HIIT groups five days per week over eight weeks with the same weekly progression of the exercise intensity (85-100% Vmax). The 1-HIIT group performed single daily sessions (6 bouts of 1 min interspersed with 1 min of passive recovery). The 3-HIIT group performed three daily sessions (2 bouts of 1 min interspersed with 1 min of passive recovery with an interval of 4 h between bouts). After the last VO2max test, the rats were euthanized, and their hearts were harvested and weighed. The results showed that 3-HIIT had similar beneficial effects to 1-HIIT in preventing body weight gain, improving VO2max, and inducing cardiac hypertrophy. These findings reveal for the first time the efficacy of an accumulated HIIT protocol on the health markers of young Wistar rats. This new HIIT protocol may be more feasible than traditional HIIT protocols as exercise can be split into very short sessions throughout a day in this new approach.

An overview of the molecular and physiological antidepressant mechanisms of physical exercise in animal models of depression.

BACKGROUND: Depression is a global disease that affects the physical and mental health of people of all ages. Non-pharmacological and unconventional methods of treatment, such as regular physical exercise, have been recommended to treat depression. METHODS: Here, we briefly review the literature about the physiological and molecular mechanisms of exercise antidepressants in depressive-like behavior in animal models of depression. RESULTS: The main hysiological and molecular mechanisms of physical exercise in depression include blood flow changes in several areas of the brain, increase in brain serotonin synthesis, increase in antioxidant enzymes, increase in serum and brain brain-derived neuro factor (BDNF) levels, decrease in cortisol levels and reduced inflammation in peripheral and brain tissues. Physical exercise also leads to increased activation of the phosphatidylinositol-3-kinase (PI3K), PGC-1α/FNDC5/Irisin pathway, BDNF concentrations (serum and cerebral), extracellular signal-regulated kinase and cAMP-response element binding protein (mainly in neurons of the hippocampus and prefrontal cortex), which together contribute to fight or inhibit the development of depression symptoms. These molecular and physiological mechanisms work in synchrony, further enhancing their effects. CONCLUSION: Physical exercise can be used as a safe and effective non-pharmacological treatment in depression.

Moderate-intensity continuous training and high-intensity interval training improve cognition, and BDNF levels of middle-aged overweight men.

The prevalence of overweight and obesity is increasing worldwide, which has been associated with poor cognitive outcomes. Participating in regular physical exercise may also improve cognition, and levels of brain-derived neurotrophic factor (BDNF), but the optimal exercise prescription remains to be elucidated. The purpose of the present study is to compare the effects of moderate intensity continuous training (MICT) and high intensity interval training (HIIT) on cognition, and serum BDNF levels in middle-aged and overweight men. Twenty-five sedentary, overweight men participated in the 8-week training intervention. Subjects were randomized into MICT (n = 12) or HIIT (n = 13) and performed exercise sessions 3x/week for 8-weeks. Cognitive function, and serum BDNF levels were assessed pre- and post-intervention. Statistical analysis was carried out using the Graph Pad Prism 7.0, and the level of significance was set at 5%. Significant improvements were observed in cognitive test scores, and BDNF levels in MICT and HIIT groups (p < 0.05). There were no significant differences in cognitive function between MICT and HIIT. The present study implicates that 8 weeks of MICT or HIIT may be a very useful non-pharmacological treatment option to improve cognitive function, and BDNF levels in middle-aged overweight men.

Neurological consequences of exercise during prenatal Zika virus exposure to mice pups.

PURPOSE/AIM: Zika virus (ZIKV) infection during the pregnancy period is related to microcephaly and neurobehavioral disorders at birth, while prenatal exercise is supposed to provide neuroprotection in newborns pups. The aim of this study was to investigate the neurological consequences of exercise during prenatal ZIKV exposure to mice pups. MATERIAL AND METHODS: Twelve weeks female mice were randomly assigned into three groups: Control group, intraperitoneally injected with saline (Control); untrained group, intraperitoneally injected with ZIKV (ZIKV); and trained group, intraperitoneally injected with ZIKV (ZIKV/swim). There was one familiarization week prior to the beginning of the swimming training. Dams swam for 60 min/session, 5 days/week, during 4 weeks. Mating occurred between the fifth and seventh day of the first week of the swimming training. ZIKV 106 plaque-forming units/100 µl (106 PFUs/100 µl) or an equal volume of saline was intraperitoneally injected in the pregnant mice at embryonic day 10.5. Pup's body mass and brain weight were measured at postnatal day 1 (P1). Behavioral tests were performed from P30 to P35. Thereafter, hippocampal levels of syntaxin-1, GFAP, IBA-1, and BDNF were measured. RESULTS: Exercise during prenatal ZIKV exposure prevented brain atrophy, development of depression, anxiety, and disruption of social behavior. Exercise during prenatal ZIKV exposure inhibited the overexpression of microglia (IBA-1) and astrocytes (GFAP), with reduction of BDNF levels in the hippocampi of female and male mice pups. No significant changes were seen in syntaxin-1 levels. CONCLUSION: Our findings reveal beneficial effects of exercise during pregnancy exposure to ZIKV in mice pups.

Endurance and high-intensity interval training improve the levels of anxiety and quality of life in overweight men.

OBJECTIVE: Body mass index (BMI) values of 25 kg/m2 or more have been associated with poor cognitive outcomes, reduced health-related quality of life (HRQoL), and mental health disorders. Participating in regular exercise may improve these negative outcomes. However, the optimal exercise prescription remains to be clarified. The purpose of the present study is to compare the effects of moderate-intensity continuous training (MICT) and high-intensity interval training (HIIT) on HRQoL, depression, and anxiety levels in middle-aged overweight men. METHODS: Twenty-five sedentary, overweight men participated in the 8-week training intervention. Subjects were randomized into MICT or HIIT and performed exercise sessions three times per week for 8 weeks. Participants answered the Physical Activity Readiness Questionnaire, the Short Form-36 survey, the Beck Depression Inventory-II, and the Beck Anxiety Inventory. Statistical analysis was carried out using the GraphPad Prism 7.0, and the level of significance was set at 5% to quantitative variables. RESULTS: HRQoL scores were enhanced to all domains of both the groups. MICT and HIIT did not significantly change the depression levels in middle-aged overweight men (p>0.05). Nevertheless, MICT was capable to reduce the anxiety levels in middle-aged overweight men (p<0.05). However, there was not a significant change in the anxiety levels at the HIIT group. CONCLUSIONS: HIIT may be a useful treatment to improve the HRQoL, but MICT alone can positively impact the anxiety levels in middle-aged overweight men.

Endurance and high-intensity interval training improve the levels of anxiety and quality of life in overweight men

SUMMARY OBJECTIVE Body mass index (BMI) values of 25 kg/m2 or more have been associated with poor cognitive outcomes, reduced health-related quality of life (HRQoL), and mental health disorders. Participating in regular exercise may improve these negative outcomes. However, the optimal exercise prescription remains to be clarified. The purpose of the present study is to compare the effects of moderate-intensity continuous training (MICT) and high-intensity interval training (HIIT) on HRQoL, depression, and anxiety levels in middle-aged overweight men. METHODS Twenty-five sedentary, overweight men participated in the 8-week training intervention. Subjects were randomized into MICT or HIIT and performed exercise sessions three times per week for 8 weeks. Participants answered the Physical Activity Readiness Questionnaire, the Short Form-36 survey, the Beck Depression Inventory-II, and the Beck Anxiety Inventory. Statistical analysis was carried out using the GraphPad Prism 7.0, and the level of significance was set at 5% to quantitative variables. RESULTS HRQoL scores were enhanced to all domains of both the groups. MICT and HIIT did not significantly change the depression levels in middle-aged overweight men (p>0.05). Nevertheless, MICT was capable to reduce the anxiety levels in middle-aged overweight men (p<0.05). However, there was not a significant change in the anxiety levels at the HIIT group. CONCLUSIONS HIIT may be a useful treatment to improve the HRQoL, but MICT alone can positively impact the anxiety levels in middle-aged overweight men.

Physical exercise consequences on memory in obesity: A systematic review.

Obesity is associated with changes in memory. Thus, the aim of this systematic review was to investigate the physical exercise consequences on memory in obesity. A search was carried out in the PubMed, Lilacs, and Scielo databases with the following descriptors: "physical exercise," "memory," and "obesity." A total of 16 studies were analyzed in this review. Low, moderate, and high intensity exercise training showed positive effects on memory in patients with obesity (100%). The animal models of obesity used in their physical exercise protocols: treadmill (72.7%) or wheel running (27.3%). Most of the animal studies (81.8%) revealed positive effects of the physical exercise protocol on memory in obesity. Mouse was the most commonly used animal (54.5%), and a 60% high-fat diet (HFD) was the most commonly method used to induce obesity (82%). We did not identify any knockout model of obesity that was used to evaluate memory and used physical exercise as the main intervention. Thus, exercise training, independently if it is resistance or endurance training, seems to be an excellent intervention to prevent and inhibit cognitive impairment and memory loss on obese patients and animal models of obesity.

Effects of physical exercise on memory in type 2 diabetes: a brief review.

Type 2 diabetes (T2D) is a metabolic disorder that can lead to memory impairment. T2D main features are insulin resistance and hyperglycemia. Physical exercise is a non-pharmacological intervention that can regulate glycemic levels and fight insulin resistance in T2D, but whether it influences memory has been discussed. There are 2 main types of physical exercise: aerobic exercise and resistance exercise. Here, we review about the consequences of different physical exercise protocols on memory in diabetic subjects and animal models of T2D. Physical exercise, aerobic or resistance training, most of the times, is a capable agent to prevent and treat memory loss on diabetic subjects and animal models of T2D. However, whether aerobic and resistance training combined improve memory in subjects with T2D remains controversial. Regarding animal models of T2D, aerobic and resistance training have been showed to be capable to prevent and treat memory loss. Acute and chronic protocols of exercise, generally, induce positive physiological responses and adaptations in T2D, such as a better glucose control. The ideal physical exercise protocol that will produce the best benefits to diabetic subjects and to animal models of T2D has not been described yet. A variety of combination between intensity, volume, frequency, and duration of the physical exercise protocol on future studies is necessary to both diabetic subjects and animal models of T2D to determine the best protocol that will induce more benefits on memory in T2D.