High-intensity Exercise Protocol Research Articles

Energy matching of a high-intensity exercise protocol with a low-intensity exercise protocol in young people

© 2021 Springer Nature Switzerland AG. This is the accepted manuscript version of an article which has been published in final form at https://doi.org/10.1007/s11332-021-00774-3

The influence of maximal and submaximal cyclic concentric and eccentric exercise on chondrocyte death and synovial fluid proteins in the rabbit knee

BackgroundMechanical stimulation of joints regulates the biosynthetic activity of chondrocytes. It has been argued that excessive loading might cause chondrocyte death, leading to degeneration of cartilage and cause osteoarthritis. The aims of this study were to apply a high, short-term loading, and a low intensity, long-term loading protocol to intact joints in life animals and determine changes in synovial fluid and the percentage of dead cells in rabbit knee cartilage. MethodNine rabbits were subjected to unilateral exercise loading consisting of five sets of 10 maximal eccentric knee contractions. Another 6 rabbits were subjected to submaximal concentric contractions for 30 min at 20% of the maximum isometric knee extensor force. Contralateral joints served as unloaded controls. Cell viability was assessed using confocal microscopy. Synovial fluid was analyzed for total protein concentration and total number of identifiable proteins and was compared to protein content of control rabbits (n = 4). FindingsNeither the high-intensity, short-term nor the low-intensity, long-term loading protocol caused increased chondrocyte death compared to the unloaded control joints. Total synovial fluid protein concentration was the same before and after exercise. Following the high-intensity exercise protocol, the number of identifiable proteins was decreased, while following the low-intensity exercise protocol, the number of identifiable proteins was increased compared to control. InterpretationChondrocytes are well protected in the intact joint and withstood maximal eccentric muscular loading, and maximal endurance loading. Synovial fluid protein content was changed after exercise, and these changes depended crucially on the type of loading.

Positive Affective and Enjoyment Responses to Four High-Intensity Interval Exercise Protocols.

Several variables can be manipulated to compose high-intensity interval exercise (HIIE) protocols, and these different combinations may evoke different psychological responses (affect, enjoyment, mood, and perceived exertion). This study investigated psychological responses during four HIIE protocols. Following anthropometric measurements and two maximal exercise tests, 23 physically inactive adults (11 males [Mage = 25.6, SD = 4.8 years; Mbody mass = 68.5, SD = 12.2 kg; Mheight = 1.72, SD = 0.08 m] and 12 females [Mage = 25.0, SD = 3.5 years; Mbody mass = 57.2, SD = 8.7 kg; Mheight = 1.59, SD = 0.06 m]) performed four different types of HIIE on different days: (a) Long-interval HIIE (HIIEL-10 × 60 seconds:60 seconds), (b) Short-interval HIIE (HIIES-2 blocks of 10 × 30 seconds:30 seconds with 120 seconds between blocks), (c) Repeated Sprint Training (19 × 6 seconds all out:40 seconds), and (d) Sprint Interval Training (4 × 30 seconds all-out efforts: 240 seconds). We used a final session to assess participants' HIIE preference. We recorded participant reports of affect, mood, and perceived exertion throughout protocols, and we recorded enjoyment after exercise session. Perceived exertion significantly increased across all HIIE protocols (p < .001), with higher values in the first quartile during Sprint Interval Training versus HIIEL (p = .033). Affective response presented higher values pre-exercise and at the first quartile compared with all other moments (p < .001). Tension (p < .001) and depression (p = .013) decreased from pre- to post-exercise in all experimental conditions. At pre-exercise, female participants were tenser than males (p = .018), though males presented higher pre-exercise vigor scores than females (p = .023). Vigor increased over time for females (p = .022). Enjoyment did not vary between sexes or protocols. Participants expressed a higher preference for Repeated Sprint Training. HIIE protocols promoted positive psychological responses for physically inactive young adults, and exercise designs may modulate psychological responses.

Current Concepts in Healthy Aging and Physical Activity: A Viewpoint.

Physical activity plays an important role for achieving healthy aging by promoting independence and increasing the quality of life. However, current guidelines for physical activity in older adults may be difficult to achieve in an older population. Indeed, there is evidence to suggest that increasing exercise intensity in older adults may be associated with greater reductions in the risk of cardiovascular disease and mortality. Therefore, the idea prescribing high-intensity exercise protocols such as high-intensity interval training and high-intensity resistance training becomes an intriguing strategy for healthy aging. Collectively, the literature review in this viewpoint will briefly focus on summarizing alternative/novel time-efficient approaches in physical activity toward healthy aging. Our goal is to hopefully open a discussion on possibly revising the current physical activity guidelines in older adults.

Comparison of brain structure between pain-susceptible and asymptomatic individuals following experimental induction of low back pain

Background ContextPeripheral differences often do not adequately account for variation in reports of pain intensity in people with musculoskeletal pain. PurposeHere we sought to determine the extent to which structural differences in the brain (grey matter density) of pain free individuals might relate to subsequent pain (or lack thereof) after standardized peripheral muscle injury (ie, micro trauma from high intensity exercise). Study DesignThis was an observational laboratory-based study that was a secondary analysis from a larger trial. MethodsParticipants completed baseline testing (functional MRI and quantitative pain testing) followed by high intensity trunk exercise to induce delayed onset muscle soreness in the erector spinae. Forty-eight hours later, back pain intensity ratings were collected and all participants were re-imaged. Grey matter density was determined using voxel-based morphometry. The “asymptomatic” group (no reports of any pain within 48 hours after induction) to a ‘pain’ group (rating of pain at rest and movement pf>20 on a 101-point numeric rating scale). ResultsOur results revealed several large clusters where, compared to participants with pain, asymptomatic participants had significant greater grey matter density. These brain regions included left medial frontal gyrus, left middle occipital gyrus, left middle temporal gyrus, left inferior frontal gyrus, and right superior frontal gyrus. ConclusionsLower grey matter density in brain regions previously linked to discriminative, emotional, and cognitive aspects of cortical processing are associated with reporting musculoskeletal pain after a standardized peripheral muscle injury. Clinical SignificanceCortical gray matter density of people without any pain may influence response to a standardized high intensity exercise protocol. This finding adds further support to the relevance of central factors in explaining the tremendous individual variability in pain report following acute musculoskeletal injury.

A Comparison between the Recovery Responses Following an Eccentrically Loaded Bench Press Protocol Vs. Regular Loading in Highly Trained Men.

The purpose of this study was to compare the physiological responses of a single bout of an eccentric accentuated bench press protocol (120% of 1RM in the eccentric phase/80% in the concentric phase; [120/80]) versus a regular high-intensity exercise protocol (80%/80%; [80/80]) in resistance-trained men. Eleven men (age = 25.6 ± 3.9 y; body mass = 84.6 ± 11.2 kg; body height = 176.4 ± 3.9 cm) with 6.3 ± 3.4 y of resistance training experience performed each protocol in counterbalanced, randomized order. Isometric, isokinetic and ballistic tests were performed at the bench press (IBPF, ISOK and BTP, respectively) at baseline (BL), 15-min (15P), 24-h (24P), and 48-h (48P) post-exercise for each testing session. In addition, muscle thickness of the pectoralis major (PecMT) was measured at the same timepoints via ultrasound. Significantly greater reductions in BTP (p < 0.001), peak force during both ISOK (p = 0.005) and IBPF (p = 0.006) at 15P were detected in 120/80 compared to 80/80. BTP was still significantly (p = 0.009) impaired at 48P following the 120/80 protocol, while no differences were noted following 80/80. PecMt was significantly elevated following both 120/80 and 80/80 (p < 0.05) at 15P, but significant differences between the trials were present at 15P and 24P (p = 0.005 and p = 0.008, respectively). Results indicated that heavy eccentric loading during the bench press exercise caused greater performance deficits than a bout of traditionally loaded high intensity resistance exercise. Power performance appears to be more influenced by the 120/80 protocol than isometric peak force. Eccentrically loaded exercise sessions should be separated by at least 48 hours to obtain a complete recovery of the initial muscle morphology and performance.

A short bout of high-intensity exercise alters ipsilesional motor cortical excitability post-stroke

ABSTRACT Background: Acute exercise can increase motor cortical excitability and enhance motor learning in healthy individuals, an effect known as exercise priming. Whether it has the same effects in people with stroke is unclear. Objectives: The objective of this study was to investigate whether a short, clinically-feasible high-intensity exercise protocol can increase motor cortical excitability in non-exercised muscles of chronic stroke survivors. Methods: Thirteen participants with chronic, unilateral stroke participated in two sessions, at least one week apart, in a crossover design. In each session, they underwent either high-intensity lower extremity exercise or quiet rest. Motor cortical excitability of the extensor carpi radialis muscles was measured bilaterally with transcranial magnetic stimulation before and immediately after either exercise or rest. Motor cortical excitability changes (post-exercise or rest measures normalized to pre-test measures) were compared between exercise vs. rest conditions. Results: All participants were able to reach the target high-intensity exercise level. Blood lactate levels increased significantly after exercise (p < .001, d = 2.85). Resting motor evoked potentials from the lesioned hemisphere increased after exercise (mean 1.66; 95% CI: 1.19, 2.13) compared to the rest condition (mean 1.23; 95% CI: 0.64, 1.82), p = .046, d = 2.76, but this was not the case for the non-lesioned hemisphere (p = .406, d = 0.25). Conclusions: High-intensity exercise can increase lesioned hemisphere motor cortical excitability in a non-exercised muscle post-stroke. Our short and clinically-advantageous exercise protocol shows promise as a potential priming method in stroke rehabilitation.

Neuromuscular Fatigue and Metabolism during High-Intensity Intermittent Exercise.

To examine the degree of neuromuscular fatigue development along with changes in muscle metabolism during two work-matched high-intensity intermittent exercise protocols in trained individuals. In a randomized, counter-balanced, crossover design, 11 endurance-trained men performed high-intensity intermittent cycle exercise protocols matched for total work and including either multiple short-duration (18 × 5 s; SS) or long-duration (6 × 20 s; LS) sprints. Neuromuscular fatigue was determined by preexercise to postexercise changes in maximal voluntary contraction force, voluntary activation level and contractile properties of the quadriceps muscle. Metabolites and pH were measured in vastus lateralis muscle biopsies taken before and after the first and last sprint of each exercise protocol. Peak power output (11% ± 2% vs 16% ± 8%, P < 0.01), maximal voluntary contraction (10% ± 5% vs 25% ± 6%, P < 0.05), and peak twitch force (34% ± 5% vs 67% ± 5%, P < 0.01) declined to a lesser extent in SS than LS, whereas voluntary activation level decreased similarly in SS and LS (10% ± 2% vs 11% ± 4%). Muscle [phosphocreatine] before the last sprint was 1.5-fold lower in SS than LS (P < 0.001). Preexercise to postexercise intramuscular accumulation of lactate and H was twofold and threefold lower, respectively, in SS than LS (P < 0.001), whereas muscle glycogen depletion was similar in SS and LS. Rate of muscle glycolysis was similar in SS and LS during the first sprint, but twofold higher in SS than LS during the last sprint (P < 0.05). These findings indicate that, in endurance-trained individuals, multiple long-sprints induce larger impairments in performance along with greater degrees of peripheral fatigue compared to work-matched multiple short-sprints, with these differences being possibly attributed to more extensive intramuscular accumulation of lactate/H and to lower rates of glycolysis during multiple long-sprint exercise.

An intensive swallowing exercise protocol for improving swallowing physiology in older adults with radiographically confirmed dysphagia.

PurposeThe aim of this study was to investigate improvements in swallowing function and physiology in a series of healthy older adults with radiographically confirmed dysphagia, following completion of an exercise-based swallowing intervention.Patients and methodsNine otherwise healthy older adults (six females, mean age =75.3, SD =5.3) had confirmed impairments in swallowing safety and/or efficiency on a modified barium swallow study. Each participant completed an 8-week swallowing treatment protocol including effortful swallows, Mendelsohn maneuvers, tongue-hold swallows, supraglottic swallows, Shaker exercises and effortful pitch glides. Treatment sessions were conducted once per week with additional daily home practice. Penetration–Aspiration Scale and the Modified Barium Swallowing Impairment Profile (MBSImP) were scored in a blind and randomized fashion to examine changes to swallowing function and physiology from baseline to post-treatment.ResultsThere were significant improvements in swallowing physiology as represented by improved oral and pharyngeal composite scores of the MBSImP. Specific components to demonstrate statistical improvement included initiation of the pharyngeal swallow, laryngeal elevation and pharyngeal residue. There was a nonsignificant reduction in median PAS scores.ConclusionSwallowing physiology can be improved using this standardized high-intensity exercise protocol in healthy adults with evidence of dysphagia. Future research is needed to examine the individual potential of each exercise in isolation and to determine ideal dose and frequency. Studies on various etiological groups are warranted.

Acute effect of high-intensity interval training on metabolic and inflammatory markers in obese and overweight adolescents: Pilot study

It is still unclear whether a high-intensity interval exercise (HIIE) protocol is effective for promoting anti-inflammatory and anti-atherogenic responses. The objective of this study was to analyze the acute effects of HIIE on inflammatory and metabolic responses in obese and overweight girls and boys. Initially, the body composition of 19 sedentary volunteers was evaluated. The participants completed an interval experimental run on a treadmill (2:1 min at 95% maximum velocity, totaling ~3 km) and blood samples were collected at rest and immediately after the exercise protocol. Serum was analyzed for interleukins 6 and 10 (IL-6 and IL-10), tumor necrosis factor-α (TNF-α), cortisol, glucose, triacylglycerol (TG), non-esterified fatty acid (NEFA), plasminogen activator inhibitor-1 (PAI-1), and the lipoprotein profile. Under baseline conditions, the groups of boys and girls exhibited differences in the anthropometry measures for fat-free mass ( p = 0.011), gynoid fat ( p = 0.002), visceral fat ( p = 0.004), and glucose ( p = 0.031). After the exercise session, cholesterol, glucose, NEFA, PAI-1, IL-10, and TNF-α did not demonstrate effects for time, group, or interaction under the different conditions. Cortisol (F = 9.018; p = 0.008; partial η2 = 0.347), TG (F = 25.189; p &lt; 0.0001; partial η2 = 0.597), and IL-6 levels (F = 6.543; p = 0.020; partial η2 = 0.278) showed an effect for time. In conclusion, our results demonstrated that HIIE promoted an immune-endocrine response, increasing cortisol and IL-6 levels immediately after the exercise protocol in overweight and obese girls.

Salivary BDNF and Cortisol Responses During High-Intensity Exercise and Official Basketball Matches in Sedentary Individuals and Elite Players.

Salivary cortisol increases in response to stressors, including physical exertion and psychological stress associated with sports competition. In addition, stress may induce change in brain-derived neurotrophic factor (BDNF). However, there are still no data available to compare the salivary BDNF level in sedentary male individuals and elite team-sport male athletes, regularly involved in activities that require elevated attention and concentration. This information could contribute to the advance of understanding of the effect of regular exercise on the salivary level of BDNF, the pre-to-post change in salivary BDNF during exercise, and the association between salivary cortisol and salivary BDNF responses to physical exercise. Therefore, this study aimed to compare the concentration of salivary cortisol and BDNF, before and after exercise, in sedentary individuals and elite male basketball players. The sedentary group (23.0 ± 4.2 yrs) performed a high-intensity exercise protocol and the basketball players (18.6 ± 0.5 yrs) participated in three official basketball matches. Saliva samples were tested for cortisol and BDNF using ELISA. A significant increase in salivary cortisol from pre- to post-match was observed only for the basketball players (p < 0.05). Basketball players also presented a higher salivary BDNF concentration for both resting (pre) and post-physical exercise (p < 0.05); however, no change in pre- to post-exercise salivary BDNF was observed for either group (p > 0.05). Elevated BDNF in athletes may be associated to their repeated exposure to stressful competition situations. The current findings also suggest that different mechanisms might be involved in salivary cortisol and BDNF responses during physical exercise.

The synergism of high-intensity intermittent exercise and every-other-day intermittent fasting regimen on energy metabolism adaptations includes hexokinase activity and mitochondrial efficiency.

Visceral lipid accumulation, organ hypertrophy and a reduction in skeletal muscle strength are all signs associated with the severity of obesity-related disease. Intermittent fasting (IF) and high-intensity intermittent exercise (HIIE) are natural strategies that, individually, can prevent and help treat obesity along with metabolic syndrome and its associated diseases. However, the combinatorial effect of IF and HIIE on energetic metabolism is currently not well understood. We hypothesized that their combination could have a potential for more than strictly additive benefits. Here, we show that two months of every-other-day intermittent fasting regimen combined with a high-intensity intermittent exercise protocol (IF/HIIE) produced a synergistic effect, enhancing physical endurance (vs. control, HIIE and IF) and optimizing metabolic pathways of energy production in male Wistar rats. The IF/HIIE group presented enhanced glucose tolerance (vs. control, HIIE and IF), lower levels of plasma insulin (vs. control and HIIE), and a global activation of low Km hexokinases in liver (vs. control, HIIE and IF), heart (vs. control and HIIE) and skeletal muscle (vs. control, HIIE and IF). The IF/HIIE synergism, rather than a simply additive effect, is evidenced by increase in muscle mass and cross-section area, activation of the FoF1 ATP synthase, and the gain of characteristics suggestive of augmented mitochondrial mass and efficiency observed in this group. Finally, important reductions in plasma oxidative stress markers were present preferentially in IF/HIIE group. These findings provide new insights for the implementation of non-pharmaceutical strategies to prevent/treat metabolic syndrome and associated diseases.

Exercise patterns in older adults instructed to follow moderate- or high-intensity exercise protocol \u2013 the generation 100 study

BackgroundMaking older adults exercise and keeping them in exercise programs is a major challenge. Understanding how older adults prefer to exercise may help developing tailored exercise programs and increase sustained exercise participation in ageing populations. We aimed to describe exercise patterns, including frequency, intensity, type, location and social setting of exercise, in older adults instructed to follow continuous moderate-intensity training (MCT) or high-intensity interval training (HIIT) over a one-year period.MethodsFrequency, intensity, type, location and social setting (alone vs. together with others) of exercise were assessed using exercise logs from 618 older adults (aged 70–77 years) randomized to MCT or HIIT. All participants completed exercise logs after each exercise session they performed during one year. Pearson Chi-square tests were run to assess the association between intensity, type, location and social setting of exercise with training group.ResultsBoth groups performed 2.2 ± 1.3 exercise sessions per week during the year. Walking was the most common exercise type in both groups, but MCT had a higher proportion of walking sessions than HIIT (54.2% vs. 41.1%, p < 0.01). Compared to MCT, HIIT had a higher proportion of sessions with cycling (14.2% vs. 9.8%, p < 0.01), combined endurance and resistance training (10.3% vs. 7.5%, p < 0.01), jogging (6.5% vs. 3.2%, p < 0.01) and swimming (2.6% vs. 1.7%, p < 0.01). Outdoors was the most common exercise location in both training groups (67.8 and 59.1% of all sessions in MCT and HIIT, respectively). Compared to MCT, HIIT had a higher proportion of sessions at a gym (21.4% vs. 17.5%, p < 0.01) and sports facility (9.8% vs. 7.6%, p < 0.01). Both groups performed an equal amount of sessions alone and together with others, but women had a higher proportion of sessions together with others compared to men (56% vs. 44%, p < 0.01).ConclusionThis is the first study that has followed older adults instructed to perform MCT or HIIT over a one-year period, collected data from each exercise session they performed and provided important knowledge about their exercise patterns. This novel information may help researchers and clinicians to develop tailored exercise programs in an ageing population.

Acute high-intensity exercise test in soccer athletes affects salivary biochemical markers

Saliva has been reported as a potential biological fluid for biochemical monitoring. This study investigated salivary markers of exercise intensity, oral mucosal immunity, and redox homeostasis in soccer athletes subjected to an acute high-intensity interval exercise (HIIE) protocol characterised by a repeated sprint ability test. Thirty-two professional soccer athletes were recruited and saliva aliquots were collected at rest and immediately after HIIE protocol. When compared with pre-test values we observed that HIIE protocol induced moderate changes for total protein (p = .015; effect size (ES) = 0.51; smallest worthwhile change (SWC)factor = 5.7) and for cortisol levels (p < .0001; ES = 0.49; SWCfactor = 3.9). Lactate levels showed very large changes (p < .000; ES = 1.35; SWCfactor = 10.8), while Ig-A alterations were considered unclear. Besides, transferrin changes were trivial and maintained its levels at rest and after HIIE below the proposed threshold of 0.5 mg/dL. Regarding redox homeostasis we observed unclear effects for TBARs, MDA, GSH, GSSG, CAT, and SOD while uric acid showed large decreases (p = .005; ES = 0.80; SWCfactor = −5.4). HIIE protocol as a physical test conducted in soccer athletes increased salivary concentration of exercise intensity markers, such as lactate, total protein, and cortisol, but did not affect Ig-A levels. Redox homeostasis in saliva seems to be more related with uric acid levels as a possible key factor TBARs homeostasis.

Metabolic stress-dependent regulation of the mitochondrial biogenic molecular response to high-intensity exercise in human skeletal muscle.

Low-volume high-intensity exercise training promotes muscle mitochondrial adaptations that resemble those associated with high-volume moderate-intensity exercise training. These training-induced mitochondrial adaptations stem from the cumulative effects of transient transcriptional responses to each acute exercise bout. However, whether metabolic stress is a key mediator of the acute molecular responses to high-intensity exercise is still incompletely understood. Here we show that, by comparing different work-matched low-volume high-intensity exercise protocols, more marked metabolic perturbations were associated with enhanced mitochondrial biogenesis-related muscle mRNA responses. Furthermore, when compared with high-volume moderate-intensity exercise, only the low-volume high-intensity exercise eliciting severe metabolic stress compensated for reduced exercise volume in the induction of mitochondrial biogenic mRNA responses. The present results, besides improving our understanding of the mechanisms mediating exercise-induced mitochondrial biogenesis, may have implications for applied and clinical research that adopts exercise as a means to increase muscle mitochondrial content and function in healthy or diseased individuals. The aim of the present study was to examine the impact of exercise-induced metabolic stress on regulation of the molecular responses promoting skeletal muscle mitochondrial biogenesis. Twelve endurance-trained men performed three cycling exercise protocols characterized by different metabolic profiles in a randomized, counter-balanced order. Specifically, two work-matched low-volume supramaximal-intensity intermittent regimes, consisting of repeated-sprint (RS) and speed endurance (SE) exercise, were employed and compared with a high-volume continuous moderate-intensity exercise (CM) protocol. Vastus lateralis muscle samples were obtained before, immediately after, and 3h after exercise. SE produced the most marked metabolic perturbations as evidenced by the greatest changes in muscle lactate and pH, concomitantly with higher post-exercise plasma adrenaline levels in comparison with RS and CM. Exercise-induced phosphorylation of CaMKII and p38 MAPK was greater in SE than in RS and CM. The exercise-induced PGC-1α mRNA response was higher in SE and CM than in RS, with no difference between SE and CM. Muscle NRF-2, TFAM, MFN2, DRP1 and SOD2 mRNA content was elevated to the same extent by SE and CM, while RS had no effect on these mRNAs. The exercise-induced HSP72 mRNA response was larger in SE than in RS and CM. Thus, the present results suggest that, for a given exercise volume, the initial events associated with mitochondrial biogenesis are modulated by metabolic stress. In addition, high-intensity exercise seems to compensate for reduced exercise volume in the induction of mitochondrial biogenic molecular responses only when the intense exercise elicits marked metabolic perturbations.

The Renin–Angiotensin System, Not the Kinin–Kallikrein System, Affects Post-Exercise Proteinuria

Background/Aims: Temporary proteinuria post-exercise is common and is caused predominantly by renal haemodynamic alterations. One reason is up-regulation of angiotensin II (Ang II) due to the reducing effect of angiotensin-converting enzyme (ACE) inhibitors. However, another, ignored, reason could be the kininase effect of ACE inhibition. This study investigated how ACE inhibition reduces post-exercise proteinuria: by either Ang II up-regulation inhibition or bradykinin elevation due to kininase activity inhibition. Methods: Our study included 10 volunteers, who completed 3 high-intensity exercise protocols involving cycling at 1-week intervals. The first protocol was a control arm, the second evaluated the effect of ACE inhibition and the third examined the effect of angiotensin type 1 receptor blockade. Upon application, both agents reduced systolic and diastolic blood pressure; however, there were no statistically significant ­differences. In addition, total protein, microalbumin and ­β₂-microglobulin excretion levels in urine specimens were analysed before, 30 min after and 120 min after the exercise protocols. Results: Total protein levels in urine samples were elevated in all 3 protocols after 30 min of high-intensity exercise, compared to baseline levels. However, both ACE inhibition and angiotensin type 1 receptor blockade suppressed total protein in the 30th min. In each protocol, total protein levels returned to the baseline after 120 min. Urinary microalbumin and β₂-microglobulin levels during the control protocol were significantly higher 30 min post-exercise; however, only angiotensin type 1 receptor blockade suppressed microalbumin levels. Conclusion: The results indicated Ang II up-regulation, not bradykinin elevation, plays a role in post-exercise proteinuria.

Intensive physical training reduces intermittent hypoxia‐related vascular dysfunction by affecting the mechanisms of smooth muscle from molecular to physiological scales

Obstructive sleep apnea syndrome (OSA) is a common clinical condition produced by episodes of repeated upper airways obstruction resulting in airflow blockade (apnea) during sleep. OSA is defined as a frequent chronic disease, which is highly prevalent in the population (affecting 9% of women and 24% of men) and which increases linearly with age. Chronic intermittent hypoxia (IH), the main pathogenic consequence related to OSA, is responsible for cardiovascular morbidity, including systemic arterial hypertension, cardiac infarct, atherosclerosis, and muscular remodeling in OSA patients.Systemic hypertension is the first cardiovascular disease related to OSA, thus 50% to 90% of patients with OSA develop hypertension. The mechanisms by which intermittent hypoxia induces the hypertension are not fully explained; we still don't know exactly the cause of hypertension, which make it a difficult medical condition to control, and make standard pharmacological interventions ineffective. Thus in order to found an effective treatment for hypertension induced by IH, we have to seek a non‐pharmacological intervention.While IH is known to contribute to hypertension, physical intensive training (IT) wields beneficial effects on the cardiovascular system and is known to reduce the hypertension risk in adults. Since physical exercise decreases the risk of cardiovascular events, the magnitude of this benefit can be also used as an anti‐hypertensive intervention.We choses a high‐intensity exercise protocol (exercise sessions during 21 days, 5 times/week on rats as a double fast 24 min‐walk with a speed progressively rising from 16 to 30 m/min), to prevent the IH‐impact and examine if IT can reverse or reduce the deleterious effects of IH (alternating normoxia (21%O2) and hypoxia (5%O2) every 30 sec in the cages for 8 h/day during 3 weeks) on the vascular reactivity, muscular remodeling and prevents the occurrence of hypertension.As expected, we found beneficial effects of training on physiological parameters (heart rate, arterial pressure), but also on vascular remodeling of several vessels (thoracic, abdominal, carotidal and pulmonary arteries); in addition we were able to observe opposite effects between IH and IT on gene transcription (Q‐PCR) and protein production (western blot) of several channels associated to calcium signaling (e.g. RyR, IP3R, SERCA, TRP) in cardiovascular system. We also compared calcium transient (ΔF/F0) from sarcoplasmic reticulum between normoxic and hypoxic smooth muscle cells and the significant difference (respectively 0,69±0,15 vs 1,01±0,21, p&lt;0,05) was abolished in cells from trained rats. Taken together, these results suggest that IT could decrease the adverse effects of IH on the cardiovascular system by acting from molecular to physiological organizations of muscular tissue. These data support the hypothesis that intensive exercise training may represent a promising non‐invasive, non‐pharmacological and complementary approach for the treatment of systemic hypertension.Support or Funding InformationINSERM, University of Grenoble Alps, University of Lebanon, AUF (PCSI)This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

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

AimsDifferent 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. MethodsWistar 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 findingsBoth 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. SignificanceThese 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.

A single bout of either sprint interval training or moderate intensity continuous training reduces anxiety sensitivity: A randomized controlled trial

Interventions that reduce anxiety sensitivity (AS) may have far reaching benefits for the prevention and treatment of mental disorders. Exercise, even when limited to a single session, appears to be an efficacious intervention for reducing AS. This effect has been largely examined using moderate intensity continuous (i.e., without rest) training (MICT). High intensity exercise protocols, such as sprint interval training (SIT), have not been investigated as a strategy for reducing AS or related constructs. We examined the effects of a single session of either SIT or MICT on AS, distress tolerance (DT), and intolerance of uncertainty (IU). A total of 56 participants were randomized into either a 50-min MICT group, a 10-min SIT group, or a waitlist control group. AS, DT, and IU were measured at baseline, post-exercise session, and at 3-day and 7-day follow-ups. Both exercise groups experienced similar reductions in AS; however, these changes appeared attributable to reductions across different AS dimensions. Specifically, significant reductions in the AS Physical Concerns were noted in the SIT group whereas the MICT group experienced significant reductions in both the AS Social and Cognitive Concerns dimensions. Both DT and IU were not changed by either exercise protocol. These findings suggest that exercise protocols varying in intensity and duration can reduce AS. This knowledge could help contribute to the optimization of exercise strategies for reducing AS. Furthermore, as lack of time is frequently reported as a barrier to exercising regularly, findings that SIT reduces overall AS to a similar extent as MICT in a fraction of the time, could inform both research and practice aimed at increasing adherence to exercise protocols for psychological wellbeing.

Exogenous ketone salts do not improve cognitive responses after a high-intensity exercise protocol in healthy college-aged males.

This study examined the effects of a d-β-hydroxybutyrate (βHB) containing beverage on cognitive and performance measures during a bout of repeated Wingates. Fifteen healthy, college-aged males (mean ± SD; age: 23.1 ± 2.4 years, height: 165.4 ± 2.0 cm, mass: 81.4 ± 9.2 kg) volunteered for the present study. Trial 1 consisted of baseline measures and familiarization for the protocol. During trials 2 and 3, subjects reported to the laboratory, after a 10-h fast, and ingested 11.38 g of βHB or a placebo (PLA) beverage 30 min before exercise. Participants then completed a cognitive challenge (CC), consisting of a 5-min FitLight response task while cycling. At the cessation of the test, participants then completed four 15-s repeated Wingates with 4 min of rest between, followed by another 5-min CC response task. Blood ketones, glucose, and lactate were measured pre-CC and post-Wingates. βHB levels were significantly higher compared with PLA (0.53 vs. 0.21 mmol/L), respectively. A significant order effect was observed across trials 2 and 3 for total FitLight misses and hits, regardless of treatment. Further, there were no significant differences among Wingate power output between treatments, although fatigue index was higher in the βHB group compared with PLA (32.3 vs. 29.4 W/s), respectively. In conclusion, βHB did not improve high-intensity cycling or cognitive performance measures; however, these findings might be partially explained by the absolute dosing protocol used for βHB in the present study as opposed to a relative (g/kg) dosing protocol used in previous research.