Running Sessions Research Articles

How about running on Mars? Influence of sensorimotor coherence on running and spatial perception in simulated reduced gravity.

Motor control, including locomotion, strongly depends on the gravitational field. Recent developments such as lower-body positive pressure treadmills (LBPPT) have enabled studies on Earth about the effects of reduced body weight (BW) on walking and running, up to 60% BW. The present experiment was set up to further investigate adaptations to a more naturalistic simulated hypogravity, mimicking a Martian environment with additional visual information during running sessions on LBPPT. Twenty-nine participants performed three sessions of four successive five-min runs at preferred speed, alternating Earth- or simulated Mars-like gravity (100% vs. 38% BW). They were displayed visual scenes using a virtual reality headset to assess the effects of coherent visual flow while running. Running performance was characterized by normal ground reaction force and pelvic accelerations. The perceived upright and vection (visually-induced self-motion sensation)in dynamic visual environments were also investigated at the end of the different sessions. We found that BW reduction induced biomechanical adaptations independently of the visual context. Active peak force and stance time decreased, while flight time increased. Strong inter-individual differences in braking and push-off times appeared at 38% BW, which were not systematically observed in our previous studies at 80% and 60% BW. Additionally, the importance given to dynamic visual cues in the perceived upright diminished at 38% BW, suggesting an increased reliance on the egocentric body axis as a reference for verticality when the visual context is fully coherent with the previous locomotor activity. Also, while vection was found to decrease in case of a coherent visuomotor coupling at 100% BW (i.e., post-exposure influence), it remained unaffected by the visual context at 38% BW. Overall, our findings suggested that locomotor and perceptual adaptations were not similarly impacted, depending on the -simulated- gravity condition and visual context.

PCA of Running Biomechanics after 5 km between Novice and Experienced Runners.

Increased running experience appears to lower the risk of running-related injuries, but the mechanisms underlying this are unknown. Studying the biomechanics of runners with different running experiences before and after long-distance running can improve our understanding of the relationship between faulty running mechanics and injury. The purpose of the present study was to investigate if there were any differences in lower-limb biomechanics between runners after a 5 km run. Biomechanical data were collected from 15 novice and 15 experienced runners. Principal component analysis (PCA) with single-component reconstruction was used to identify variations in running biomechanics across the gait waveforms. A two-way repeated-measures ANOVA was conducted to explore the effects of runner and a 5 km run. Significant runner group differences were found for the kinematics and kinetics of lower-limb joints and ground reaction force (GRF) with respect to the magnitude across the stance phase. We found that novice runners exhibited greater changes in joint angles, joint moments, and GRFs than experienced runners regardless of the prolonged running session, and those patterns may relate to lower-limb injuries. The results of this study suggest that the PCA approach can provide unique insight into running biomechanics and injury mechanisms. The findings from the study could potentially guide training program developments and injury prevention protocols for runners with different running experiences.

Effect of long-term carnosine/anserine supplementation on iron regulation after a prolonged running session.

Exercise-induced hemolysis, which is caused by metabolic and/or mechanical stress during exercise, is considered a potential factor for upregulating hepcidin. Intramuscular carnosine has multiple effects including antioxidant activity. Therefore, this study aimed to determine whether long-term carnosine/anserine supplementation modulates exercise-induced hemolysis and subsequent hepcidin elevation. Seventeen healthy male participants were allocated to two different groups: participants consuming 1,500 mg/day of carnosine/anserine supplements (n = 9, C+A group) and participants consuming placebo powder supplements (n = 8, PLA group). The participants consumed carnosine/anserine or placebo supplements daily for 30.7 ± 0.4 days. They performed an 80-running session at 70% VO2peak pre-and post-supplementation. Iron regulation and inflammation in response to exercise were evaluated. Serum iron concentrations significantly increased after exercise (p < 0.01) and serum haptoglobin concentrations decreased after exercise in both groups (p < 0.01). No significant differences in these variables were observed between pre-and post-supplementation. Serum hepcidin concentration significantly increased 180 min after exercise in both groups (p < 0.01). The integrated area under the curve of hepcidin significantly decreased after supplementation (p = 0.011) but did not vary between the C+A and PLA groups. Long-term carnosine/anserine supplementation does not affect iron metabolism after a single endurance exercise session.

Functional connectivity in central nucleus of amygdala, paraventricular hypothalamus, and nucleus tractus solitarii circuits during high-intensity endurance treadmill exercise in rats

High-intensity endurance exercise (HIE) induces negative emotions alongside fatigue, suffering, and changes in cardiovascular responses, and these regulations could be important for athletic performance. Previous studies have reported that limbic and brain stem regions, including the central nucleus of the amygdala (CeA), the paraventricular nucleus of the hypothalamus (PVH), and the nucleus tractus solitarii (NTS), play important roles in emotional response and autonomic cardiovascular regulation. However, how these brain regions interact during HIE remains unclear. In this study, Wistar rats were subjected to 90-min treadmill running sessions at different endurance exercise intensities (sedentary, low-intensity, and high-intensity: 0, 20, and 34 m/min, respectively; n = 9 per group). After exercise, brain tissues were extracted and examined for c-Fos immediate early gene expression in brain regions such as the CeA, PVH, and NTS at each exercise intensity. The c-Fos-positive cells were counted, and then a partial correlation analysis was performed to examine the functional connectivity during exercise. As a result, the numbers of c-Fos-positive cells in the CeA, PVH, and NTS increased in an exercise intensity-dependent manner. Furthermore, partial correlation analyses of c-Fos-positive cells between CeA and NTS (CeA-NTS), PVH and NTS (PVH-NTS), and CeA and PVH (CeA-PVH) exhibited significant correlation coefficients during HIE but not during sedentary and low-intensity endurance exercises. Thus, these results suggest that functional connectivity between CeA-PVH, PVH-NTS, and CeA-NTS may be enhanced during HIE. This enhanced functional connectivity may also be involved in emotional and cardiovascular regulation during exercise.

Impact of physical and sports rehabilitation on the level of physical fitness of combatants

The anti-terrorist operation, the operation of the joint forces, and the full-scale war in Ukraine have a significant physical and psychological impact on the participants of the hostilities. One of the negative consequences of war is the loss of physical health which further affects the process of socialization during a peaceful life. At the same time, the process of restoring physical health with the help of physical culture and sports rehabilitation has not been researched enough, which confirms the relevance of the chosen topic. Objective: to determine the impact of physical culture and sports rehabilitation on the level of physical fitness of combatants. Material and methods: the research was carried out on the basis of the National Sports Complex "Olympiyskyi" in the group "Veteran Ten" during 2020-2021. The main sports competitions the combatants were preparing for were various marathons. 40 combatants who had completed their military service took part in the research. During the research, there were used the following methods: pedagogical experiment, and methods of mathematical statistics. Results: During a year, combatants participated in the research in the framework of which they trained and prepared to participate in mass races. The content of the training included both running exercises and exercises aimed at developing strength qualities (mainly strength endurance), flexibility, and coordination. The level of physical fitness of combatants was tested in dynamics (before the start of training and after a year of training). The level of physical fitness of combatants was determined according to the approved tests and standards of the "Annual Assessment of Physical Fitness of the Population of Ukraine". Based on the results of the research, it was established that at the initial stage, 75% of the combatants had a low level of physical fitness, 23% had a medium level, and 2% had a sufficient level. Upon the completion of the pedagogical experiment, the level of physical fitness of the combatants improved: 33% of the combatants had a low level of physical fitness, 50% had a medium level, and 17% had a sufficient level, which demonstrates the effectiveness of training sessions as a means of physical culture and sports rehabilitation. Conclusions. The positive impact of physical culture and sports rehabilitation on the level of physical fitness of combatants was determined. With the help of the tests and standards of the "Annual Assessment of Physical Fitness of the Population of Ukraine", it was discovered that the indicators of physical fitness of the combatants at the first stage of the research were in the range from 2 to 21 and on average were (11.83; 4.49) points. In the second stage, they ranged from 11 to 24, their average physical fitness score was (11.28; 3.20) points. At the same time, 46.1% of the participants of the research got an observed increase in the indicator which turned out to be statistically significant (t=13.563; df=39; p<0.05). Therefore, it can be stated that running sessions have a positive impact on the level of physical fitness of combatants.

Role of Running-Activated Neural Stem Cells in the Anatomical and Functional Recovery after Traumatic Brain Injury in p21 Knock-Out Mice.

Traumatic brain injury (TBI) represents one of the most common worldwide causes of death and disability. Clinical and animal model studies have evidenced that TBI is characterized by the loss of both gray and white matter, resulting in brain atrophy and in a decrease in neurological function. Nowadays, no effective treatments to counteract TBI-induced neurological damage are available. Due to its complex and multifactorial pathophysiology (neuro-inflammation, cytotoxicity and astroglial scar formation), cell regeneration and survival in injured brain areas are strongly hampered. Recently, it has been proposed that adult neurogenesis may represent a new approach to counteract the post-traumatic neurodegeneration. In our laboratory, we have recently shown that physical exercise induces the long-lasting enhancement of subventricular (SVZ) adult neurogenesis in a p21 (negative regulator of neural progenitor proliferation)-null mice model, with a concomitant improvement of olfactory behavioral paradigms that are strictly dependent on SVZ neurogenesis. On the basis of this evidence, we have investigated the effect of running on SVZ neurogenesis and neurorepair processes in p21 knock-out mice that were subject to TBI at the end of a 12-day session of running. Our data indicate that runner p21 ko mice show an improvement in numerous post-trauma neuro-regenerative processes, including the following: (i) an increase in neuroblasts in the SVZ; (ii) an increase in the migration stream of new neurons from the SVZ to the damaged cortical region; (iii) an enhancement of new differentiating neurons in the peri-lesioned area; (iv) an improvement in functional recovery at various times following TBI. All together, these results suggest that a running-dependent increase in subventricular neural stem cells could represent a promising tool to improve the endogenous neuro-regenerative responses following brain trauma.

Influence of Recovery Mode on the Maximum Number of Intervals Until Exhaustion During an Aerobic Interval Training Session.

Varela-Sanz, A, Sánchez-Otero, T, Tuimil, JL, Boullosa, D, and Iglesias-Soler, E. Influence of recovery mode on the maximum number of intervals until exhaustion during an aerobic interval training session. J Strength Cond Res 37(9): e510-e520, 2023-We analyzed work capacity, cardiometabolic, perceptual, and neuromuscular responses to an aerobic interval training (AIT) running session until exhaustion, with active (AR) vs. passive recovery (PR). Eight well-trained male endurance runners (36.88 ± 7.14 years, 58.22 ± 3.39 ml·kg -1 ·minute -1 ) randomly completed, after familiarizations and the University of Montreal Track Test (UMTT), 2 AIT track running sessions until exhaustion consisting in 2-minute bouts at 100% of maximum aerobic speed (MAS), with 2 minutes of recovery at 80% of the velocity associated to the second ventilatory threshold (vVT 2 ) (i.e., AR), or no exercise (i.e., PR). Oxygen consumption (V̇O 2 ), heart rate (HR), blood lactate [La], rating of perceived exertion (RPE), and countermovement jump (CMJ) were continuously monitored during sessions. The level of statistical significance was set at p ≤ 0.05. PR resulted in longer time to exhaustion during sessions (13.9 vs. 11.6 bouts, p = 0.045), but lower HR ( p < 0.01) when compared with AR. Time spent over 90% of maximum oxygen consumption (V̇O 2max ), blood lactate concentrations, neuromuscular performance, and RPE did not differ between AR and PR ( p > 0.05). Thus, PR allowed runners to perform more work intervals and, therefore, to accumulate a greater volume. On the other hand, when training goals are focused on reaching a higher chronotropic stress (i.e., higher HR) during the training session, athletes would obtain more benefits from AR. This study also demonstrates that the current volume recommendations for AIT are far below (54-64.5%) the maximum training capacity of well-trained runners.

Inter-Session Repeatability of Marker-Less Motion Capture of Treadmill Running Gait

Twenty-one experienced runners completed three treadmill running sessions on different days. Each session consisted of three consecutive 2 min trials at self-selected speeds (RPE = 3, 5, and 7). An eight-camera marker-less motion capture system and instrumented pressure treadmill (TM) collected data over the final ~25 s at each speed. Lower extremity joint angles (ankle, knee, and hip) and segmental angles (pelvis and trunk) were computed for each trial with foot contact and toe off being kinematically determined. Spatiotemporal metrics (ground contact time, step length, and cadence) were measured via TM and compared to their kinematically derived counterparts. All spatiotemporal metrics demonstrated excellent agreement (ICCs &gt; 0.98). Both intra-trial and inter-session variability, averaged across the entire running cycle, for all lower extremity joint angles in all planes were low (intra-trial: sagittal = 2.0°, frontal = 1.2°, and transverse = 1.9°; inter-session: sagittal = 1.4°, frontal = 0.8°, and transverse = 1.3°). Discrete measures of lower extremity joint and segmental angles were evaluated for inter-session reliability at foot contact, toe off, and peak value during the stance phase. On average, discrete measures demonstrated good reliability (ICCsagittal = 0.85, ICCfrontal = 0.83, and ICCtransverse = 0.77) with average standard error of measurement &lt; 1°. Marker-less motion capture reliably measured treadmill running kinematics in a group of runners demonstrating heterogenous foot strike patterns (13 rearfoot strike and 8 non-rearfoot strike) across a range of speeds (2.67–4.44 m/s).

Навчання студентів-єдиноборців бігу на 1500 м з використанням ритмічних стимулів

Purpose: to investigate the effectiveness of teaching martial arts students to run 1500 m using rhythmic stimuli. Material and methods. The following methods of pedagogical research were used to solve the research tasks: theoretical (analysis, synthesis, comparison, generalization of abstraction) and practical (observation, testing, experiment, mathematical and statistical). Martial arts students aged 18,5±0,5 years of the II year of full-time education took part in the study (n=20). Results: іndicators indicating the economy of a runner's movement were selected as characteristics that determine mastery of running technique: MAV – maximum aerobic speed; VO2max is the maximum rate of oxygen absorption. We believe that in conditions of limited time for running training (8 classes), the very increase in running efficiency indicates the athlete's understanding of the essence of this motor action. As a stimulating factor in the experimental running training program of martial arts students, running with a metronome was used with a given frequency, which increased in each session from 157 beats/min. up to 165 beats/min. The students had to run first, synchronizing their steps with the metronome, and after rest, reproduce the learned rhythm without external stimulation. The martial arts athletes of the control group studied running according to the traditional program for the same amount of time. The result of the study was significantly (p&lt;0,05) higher indicators of running cadence and results of running at the reference distance of 1500 m in the group of martial arts students who practiced using rhythmic stimuli. At the same time, there were no significant differences in the MAV and VO2max indicators in the wrestlers of both groups during the entire study period (p&gt;0,05). This indicates the effectiveness of running training in the experimental program, by improving running efficiency, rather than increasing the level of endurance. Conclusions. It was established that 8 training sessions of long running for 120 min. per week do not contribute to the increase of MAV and VO2max in martial arts students who studied both by traditional and experimental methods. The effectiveness of the application of external rhythmic stimuli with the help of a metronome in teaching martial arts students to athletics running, which is characterized by an increase in running cadence, has been revealed. This indicates an improvement in the level of ownership of transportation equipment while increasing its economy. Keywords: running, training, cadence, MAV, VO2max, pace, rhythm, martial arts, preparedness.

The physiological, perceptual and neuromuscular responses of team sport athletes to a running and cycling high intensity interval training session

PurposeThe acute physiological, perceptual and neuromuscular responses to volume-matched running and cycling high intensity interval training (HIIT) were studied in team sport athletes.MethodsIn a randomized cross-over design, 11 male team sport players completed 3 × 6 min (with 5 min between sets) repeated efforts of 15 s exercising at 120% speed (sdot{text{V}}O2max) or power (pdot{text{V}}O2max) at dot{text{V}}O2max followed by 15 s passive recovery on a treadmill or cycle ergometer, respectively.ResultsAbsolute mean dot{text{V}}O2 (ES [95% CI] = 1.46 [0.47–2.34], p < 0.001) and heart rate (ES [95% CI] = 1.53 [0.53–2.41], p = 0.001) were higher in running than cycling HIIT. Total time at > 90% dot{text{V}}O2max during the HIIT was higher for running compared to cycling (ES [95% CI] = 1.21 [0.26–2.07], p = 0.015). Overall differential RPE (dRPE) (ES [95% CI] = 0.55 [− 0.32–1.38], p = 0.094) and legs dRPE (ES [95% CI] = − 0.65 [− 1.48–0.23], p = 0.111) were similar, whereas breathing dRPE (ES [95% CI] = 1.01 [0.08–1.85], p = 0.012) was higher for running. Maximal isometric knee extension force was unchanged after running (ES [95% CI] = − 0.04 [− 0.80–0.8], p = 0.726) compared to a moderate reduction after cycling (ES [95% CI] = − 1.17 [− 2.02–0.22], p = 0.001).ConclusionCycling HIIT in team sport athletes is unlikely to meet the requirements for improving run-specific metabolic adaptation but might offer a greater lower limb neuromuscular load.

Exercise-induced FKBP8-mediated Mitophagy Via AMPK Activation In Soleus Muscle Of Rats

Scientific Abstract PURPOSE: To investigate the effects of downhill running on mitochondrial structure/function and expression levels of mitophagy-related proteins in rat skeletal muscle, and whether AMP-activated protein kinase (AMPK) plays a regulatory role in this context. METHODS: Male Sprague-Dawley rats were divided into a control (C, n = 8) or an exercise (E, n = 56) group. Rats in the E group were exercised on a treadmill down a 16° incline at 16 m/min for 90 min, and were further divided into 0 h (E0), 12 h (E12), 24 h (E24), 48 h (E48) and 72 h (E72) post-exercise sub-groups. Rats in the E0 and E12 sub-groups received acute AMPK agonist AICAR treatment (500 mg/kg via I.P.) or saline (n = 8 each) 30 min before exercise. At each time point the soleus muscle was collected under full anesthesia. Mitochondrial ultrastructural changes in skeletal muscle were observed by using a transmission electron microscope. Protein expression levels of skeletal muscle p-AMPKα1/2(T172), total AMPKα, heat shock protein 60 (HSP60), cyclophilin D (CypD), mitochondrial FK506 binding protein 8 (FKBP8/FKBP38), microtubule-associated protein 1 light chain 3 (LC3) and cytosolic cytochrome C (Cyt C) were determined by using Western blot. LC3 co-localizations with mitochondria and FKBP8 were measured by the immunofluorescence technique. One-way and two-way ANOVAs were used for data analysis. RESULTS: After downhill running, skeletal muscle mitochondrial structure appeared to be abnormal and contained a large number of mitophagosomes; the expression levels of AMPK phosphorylation (E12 = 1.81 ± 0.54), FKBP8 (E12 = 3.11 ± 0.26), LC3 (E12 = 1.80 ± 0.12), CypD (E0 = 1.41 ± 0.26) and Cyt C (E0 = 2.31 ± 0.68) and the co-localization of FKBP8 and LC3 were significantly higher, whereas the expression levels of mitochondrial quantitative protein HSP60 (E12 = 0.62 ± 0.09) were significantly lower than those in the C group (p < 0.05 to p < 0.01). AICAR treatment enhanced AMPK phosphorylation in exercised muscle and the expression levels of mitochondrial FKBP8 and LC3 involved in mitophagy. CONCLUSION: A session of downhill running activated the AMPK phosphorylation and LC3 co-localizations with mitochondria and FKBP8, and induced mitophagy and mitochondrial damage within rat skeletal muscle. (Supported by Natural Science Foundation of China grant 31900842).

Fair performance-based user recommendation in eCoaching systems

Offering timely support to users in eCoaching systems is a key factor to keep them engaged. However, coaches usually follow a lot of users, so it is hard for them to prioritize those with whom they should interact first. Timeliness is especially needed when health implications might be the consequence of a lack of support. In this paper, we focus on this last scenario, by considering an eCoaching platform for runners. Our goal is to provide a coach with a ranked list of users, according to the support they need. Moreover, we want to guarantee a fair exposure in the ranking, to make sure that users of different groups have equal opportunities to get supported. In order to do so, we first model their performance and running behavior and then present a ranking algorithm to recommend users to coaches, according to their performance in the last running session and the quality of the previous ones. We provide measures of fairness that allow us to assess the exposure of users of different groups in the ranking and propose a re-ranking algorithm to guarantee a fair exposure. Experiments on data coming from the previously mentioned platform for runners show the effectiveness of our approach on standard metrics for ranking quality assessment and its capability to provide a fair exposure to users. The source code and the preprocessed datasets are available at: https://github.com/wiguider/Fair-Performance-based-User-Recommendation-in-eCoaching-Systems.

Effect of daily treadmill running exercise on masseter muscle nociception associated with social defeat stress in mice.

We investigated the effects of social defeat stress (SDS) and treadmill running on masseter muscle nociception, which was quantified by the orofacial formalin test and c-Fos and FosB immunoreactivities in the upper cervical spinal cord (C1/C2) region in male mice. After daily SDS or non-SDS conditioning for 10 days, SDS-conditioned mice were categorized into SDS-susceptible versus resilient mice. Several mice, including non-SDS-conditioned, SDS-susceptible, and resilient mice, were selected to assess masseter muscle nociception on Day11. SDS conditioning for 10 days increased masseter muscle-evoked nocifensive behaviors and c-Fos and FosB expression in SDS-susceptible compared to non-SDS and resilient mice. The remaining SDS-susceptible and non-SDS mice were subjected to an additional 10 days of SDS plus treadmill running or sedentary sessions before assessing masseter muscle nociception on Day21. Daily treadmill running sessions reduced enhanced masseter muscle nociception in SDS-susceptible mice but not in non-SDS mice. The preventive effects of daily treadmill running immediately after each SDS conditioning for 10 days on orofacial nocifensive behaviors were assessed on Day11. Treadmill running conducted immediately after daily SDS inhibited enhanced orofacial nocifensive behaviors. These findings indicate that repeated SDS increases masseter muscle nociception, which could be prevented by daily treadmill running exercise.

Global Positioning System Watches and Electronic Journals: Are Training-Load Measures Similar in High School Cross-Country Runners?

Running programs are designed to progress training loads by manipulating the duration, frequency, and/or intensity of running sessions. While some studies use journals to monitor training load, others have used wearable technology. The purpose of this study was to compare the validity of self-reported and global positioning system (GPS)-watch-derived measures of external and internal loads in high school cross-country runners. Twenty-two high school cross-country runners participated in the study during fall 2020. Participants recorded running sessions using a GPS watch and self-reported the running session using an electronic journal. External (distance and duration) and internal loads (session rating of perceived exertion [sRPE], average, and maximum heart rate) were retrieved from the GPS watch and electronic journal. Correlations compared relationships, and Bland-Altman plots compared agreements between GPS-watch-derived and self-reported measures of training loads. We found moderate relationships between self-reported and GPS-watch-derived measures of external loads (distance: r = .76, moving duration: r = .74, and elapsed duration: r = .70) and poor relationships between internal loads (sRPE vs average heart rate: ρ = .11, sRPE vs maximal heart rate: ρ = .13). We found mean differences of -0.8km (95% = -6.3 to +4.8km) for distance, -4.5minutes (95% = -27.8 to +33.2min) for moving duration, and 2.7 minutes (95% = -27.8min to +33.2min) for elapsed duration. High school runners overreported running distance and duration using self-reports, and self-reported and GPS-watch-derived measures of internal loads demonstrated poor agreement. Coaches and clinicians should use caution when comparing results from studies using different methods of monitoring training loads.

Mitigation of MAFLD in High Fat-High Sucrose-Fructose Fed Mice by a Combination of Genistein Consumption and Exercise Training.

PurposeMetabolic dysfunction-associated fatty liver disease (MAFLD) is fueled by escalations in both sedentary behavior and caloric intake and is noted in obese type 2 diabetic (T2DM) patients. This study aimed to examine the effects of exercise and the phytoestrogen genistein in mice fed a high fat (60% fat) high sugar (55% fructose with 45% sucrose), HFHS diet.MethodsMale C57BL/6J mice were assigned to five groups: HFHS, HFHS with genistein (600 mg/kg diet, HFHS+Gen), HFHS with moderate exercise (HFHS+Ex), and HFHS with combined genistein and moderate exercise (HFHS-Gen+Ex). Control lean mice were fed standard chow and water. Exercise consisted of 30-minute sessions of treadmill running five days/week for the 12-week study duration. Body weight was assessed weekly. Liver, kidney, fecal pellets and serum were extracted at the end of the study and maintained at −80°C.ResultsAfter 12 weeks of treatment, mice in the HFHS group had the highest hepatic lipid content. Plasma levels of glucose, insulin, leptin, cholesterol, amylin, and total fat content were significantly elevated in HFHS mice compared to control mice. HFHS feeding increased protein expression of carnitine palmitoyltransferase 1b (CPT-1b isoform) in gastrocnemius, CPT1a, glucose transporter protein 2 (GLUT2), glucocorticoid receptor (GR), and fructose 1,6-bisphosphate 1 (FBP1) expression in liver. Exercise alone had minor effects on these metabolic abnormalities. Genistein alone resulted in improvements in body weight, fat content, amylin, insulin sensitivity, and liver histopathology, GR, FBP1, and acetyl-CoA carboxylase 1 (ACC1). Combination treatment resulted in additional metabolic improvements, including reductions in hepatic lipid content and lipid area, alanine transferase activity, CPT1b, and CPT1a.ConclusionOur results indicate that a HFHS diet is obesogenic, inducing metabolic perturbations consistent with T2DM and MAFLD. Genistein alone and genistein combined with moderate intensity exercise were effective in reducing MAFLD and the aberrations induced by chronic HFHS feeding.

Multiple regression analyses to determine the effect of sweating rate and tattoo characteristics on sweat outcome measures during exercise

PurposeTo compare local sweating rate (LSR) and local sweat sodium ([Na+]), chloride ([Cl−]), and potassium ([K+]) concentrations of tattooed skin and contralateral non-tattooed skin during exercise. MethodsThirty-three recreational exercisers (17 men, 16 women) with ≥ 1 unilateral permanent tattoo on the torso/arms were tested during cycling, running, or fitness sessions (26 ± 4 °C and 54 ± 13% relative humidity). Forty-eight tattoos with a range of ink colors, ages (3 weeks to 20 years), and densities (10–100%) were included. Before exercise, the skin was cleaned with alcohol and patches (3 M Tegaderm + Pad) were placed on the tattooed and contralateral non-tattooed skin. LSR was calculated from sweat mass (0.80 ± 0.31 g), patch surface area (11.9 cm2), and duration (62 ± 14 min). Sweat [Na+], [Cl−], and [K+] were measured via ion chromatography.ResultsBased on the analysis of variance results, there were no differences between tattooed and non-tattooed skin for LSR (1.16 ± 0.52 vs. 1.12 ± 0.53 mg/cm2/min; p = 0.51), sweat [Na+] (60.2 ± 23.5 vs. 58.5 ± 22.7 mmol/L; p = 0.27), sweat [Cl−] (52.1 ± 22.4 vs. 50.6 ± 22.0 mmol/L; p = 0.31), or sweat [K+] (5.8 ± 1.6 vs. 5.9 ± 1.4 mmol/L; p = 0.31). Multiple regression analyses suggested that younger tattoos were associated with higher sweat [Na+] (p = 0.045) and colorful tattoos were associated with higher sweat [Cl−] (p = 0.04) compared with contralateral non-tattooed skin. Otherwise, there were no effects of LSR or tattoo characteristics on regression models for LSR or sweat electrolyte concentrations.ConclusionThere were no effects of tattoos on LSR and sweat [K+] during exercise-induced sweating, but tattoo age and color had small effects on sweat [Na+] and sweat [Cl−], respectively.Clinical trial identifiersNCT04240951 was registered on January 27, 2020 and NCT04920266 was registered on June 9, 2021.

An Electromyography (EMG) Analysis After Pre-Cooling Between Male and Female in Recreational Runners

Background: Maintaining internal body temperature is critical for the runner’s performance. The inability to reduce the rising temperature may result in hyperthermia and muscle fatigue. Pre-cooling may lower core temperature, allowing for greater heat storage during exercise and delaying thermally-induced fatigue, as well as increased motor output through decrease electrical activity by cooling the muscles. Furthermore, there have been lack studies that compare electrical activity in muscle between gender differences in response to prolonged exercise after pre-cooling. Objective: The purpose of this study to investigate the changes in electrical activity pre and post cold water immersion (CWI) in male and female recreational runners. Methods: This case involved 2 males and 2 females aged 20 years old who are physically active runner with normal-weight BMI. The outcome was measured using electromyography (EMG) which was carried out every 4 minutes while 1st and 2nd running sessions (16 minutes). Results: Male subjects' electrical activity (mV) decreased significantly between 8 to 16 minutes and 16 to 8 minutes (p=0.04, p0.05). But not in female subjects (p0.05). Conclusion: It can be concluded that CWI as pre-cooling had an effect of lowering the electrical activity level in the muscle during running in both genders.Keywords: electromyography, electrical activity, cold water immersion, gender, recreational runner

Effects of Low-Intensity and Long-Term Aerobic Exercise on the Psoas Muscle of mdx Mice: An Experimental Model of Duchenne Muscular Dystrophy.

Duchenne muscular dystrophy (DMD) is a muscle disease characterized by the absence of the protein dystrophin, which causes a loss of sarcolemma integrity, determining recurrent muscle injuries, decrease in muscle function, and progressive degeneration. Currently, there is a need for therapeutic treatments to improve the quality of life of DMD patients. Here, we investigated the effects of a low-intensity aerobic training (37 sessions) on satellite cells, peroxisome proliferator-activated receptor-gamma coactivator (PGC)-1α protein (PGC-1α), and different types of fibers of the psoas muscle from mdx mice (DMD experimental model). Wildtype and mdx mice were randomly divided into sedentary and trained groups (n = 24). Trained animals were subjected to 37 sessions of low-intensity running on a motorized treadmill. Subsequently, the psoas muscle was excised and analyzed by immunofluorescence for dystrophin, satellite cells, myosin heavy chain (MHC), and PGC-1α content. The minimal Feret’s diameters of the fibers were measured, and light microscopy was applied to observe general morphological features of the muscles. The training (37 sessions) improved morphological features in muscles from mdx mice and caused an increase in the number of quiescent/activated satellite cells. It also increased the content of PGC-1α in the mdx group. We concluded that low-intensity aerobic exercise (37 sessions) was able to reverse deleterious changes determined by DMD.

Active vs. passive recovery during an aerobic interval training session in well-trained runners

PurposeTo compare cardio-metabolic, perceptual and neuromuscular responses to an aerobic interval training (AIT) running session, with active (AR) vs. passive recovery (PR).MethodsEleven well-trained male distance runners (36.63 ± 6.93 years, 59.26 ± 5.27 mL·kg−1·min−1, ⁓ 35 min in 10 km) completed the University of Montréal Track Test (UMTT) and 2 AIT sessions on track in random order, which consisted of 4 × 2 min at 100% of the maximum aerobic speed (MAS), with 2 min of AR at 80% of the velocity associated to the second ventilatory threshold (vVT2), or no exercise (i.e., PR). During sessions, oxygen consumption (V̇O2), heart rate (HR), blood lactate [La], rating of perceived exertion (RPE), and countermovement jump (CMJ) were continuously monitored.ResultsThere were no differences in time spent in the “red zone” (i.e. > 90% V̇O2max) between sessions (222 ± 73 s AR vs. 230 ± 104 s PR, p = 0.588), although the PR exhibited a greater time spent at peak V̇O2 close to significance (117 ± 114 vs. 158 ± 109 s, p = 0.056). However, the AR elicited a higher mean V̇O2 (49.62 ± 5.91 vs. 47.46 ± 4.20 mL·kg−1·min−1, p = 0.021). The AR favored a lower [La] after sessions (6.93 ± 2.22 vs. 6.24 ± 1.93 mmol·L−1, p = 0.016) and a higher RPE during sessions (15 ± 0.45 vs. 14 ± 0.47, p = 0.045). Meanwhile, the CMJ was significantly potentiated during both sessions.ConclusionConsidering that PR elicited lower perceptual loading for a similar cardiorespiratory response, its use would be preferable, at least, for this type of AIT running sessions.

Reducing the peak tibial acceleration of running by music-based biofeedback: A quasi-randomized controlled trial.

Running retraining with the use of biofeedback on an impact measure has been executed or evaluated in the biomechanics laboratory. Here, the execution and evaluation of feedback-driven retraining are taken out of the laboratory. To determine whether biofeedback can reduce the peak tibial acceleration with or without affecting the running cadence in a 3-week retraining protocol. Quasi-randomized controlled trial. Twenty runners with high peak tibial acceleration were allocated to either the retraining (n=10, 32.1±7.8years, 10.9±2.8g) or control (n=10, 39.1±10.4years, 13.0±3.9g) groups. They performed six running sessions in an athletic training environment. A body-worn system collected axial tibial acceleration and provided real-time feedback. The retraining group received music-based biofeedback in a faded feedback scheme. Pink noise was superimposed on tempo-synchronized music when the peak tibial acceleration was ≥70% of the runner's baseline. The control group received tempo-synchronized music, which acted as a placebo for blinding purposes. Speed feedback was provided to obtain a stable running speed of ~2.9m·s-1 . Peak tibial acceleration and running cadence were evaluated. A significant group-by-feedback interaction effect was detected for peak tibial acceleration. The experimental group had a decrease in peak tibial acceleration by 25.5% (mean: 10.9±2.8g versus 8.1±3.9g, p=0.008, d=1.08, mean difference=2.77 [0.94, 4.61]) without changing the running cadence. The control group had no statistically significant change in peak tibial acceleration nor in running cadence. The retraining protocol was effective at reducing the peak tibial acceleration in high-impact runners by reacting to music-based biofeedback that was provided in real time per wearable technology in a training environment. This reduction magnitude may have meaningful influences on injury risk.