Moderate-intensity Cycling Research Articles

Exercise-induced changes in gene expression do not mediate post exertional malaise in Gulf War illness

BackgroundPost-exertional malaise (PEM) is considered a characteristic feature of chronic multi-symptom illnesses (CMI) like Gulf War illness (GWI); however, its pathophysiology remains understudied. Previous investigations in other CMI populations (i.e., Myalgic Encephalomyelitis/Chronic Fatigue Syndrome) have reported associations between PEM and expression of genes coding for adrenergic, metabolic, and immune function. ObjectivesTo investigate whether PEM is meditated by gene expression in Veterans with GWI. MethodsVeterans with GWI (n = 37) and healthy control Gulf War Veterans (n = 25) provided blood samples before and after 30-min of cycling at 70% of age-predicted heart rate reserve. Relative quantification of gene expression, symptom measurements, and select cardiopulmonary parameters were compared between groups at pre-, 30 minpost-, and 24 hpost-exercise using a doubly multivariate repeated measures analysis of variance (RM-MANOVA). Mediation analyses were used to test indirect effects of changes in gene expression on symptom responses (i.e., PEM) to the standardized exercise challenge. ResultsVeterans with GWI experienced large symptom exacerbations following exercise compared to controls (Cohen's d: 1.65; p < 0.05). Expression of β-actin (ACTB), catechol-O-methyltransferase (COMT), and toll-like receptor 4 (TLR4) decreased in Veterans with GWI at 30 min (p < 0.05) and 24 h post-exercise (p < 0.05). Changes in gene expression did not mediate post-exercise symptom exacerbation in GWI (Indirect Effect Slope Coefficient: 0.06 – 0.02; 95% CI: 0.19, 0.12). ConclusionAn acute bout of moderate intensity cycling reduced the expression of select structural, adrenergic, and immune genes in Veterans with GWI, but the pathophysiological relevance to PEM is unclear.

A single bout of moderate-intensity aerobic exercise improves motor learning in premanifest and early Huntington's disease.

Cardiorespiratory exercise has emerged as a promising candidate to modify disease progression in Huntington's disease (HD). In animal models, exercise has been found to alter biomarkers of neuroplasticity and delay evidence of disease, and some interventions-including exercise-have shown benefits in human HD patients. In healthy human populations, increasing evidence suggests that even a single bout of exercise can improve motor learning. In this pilot study, we investigated the effect of a single bout of moderate intensity aerobic exercise on motor skill learning in presymptomatic and early manifest HD patients. Participants were allocated to either an exercise (n = 10) or control (n = 10) group. They performed either 20 min of moderate intensity cycling or rest before practicing a novel motor task, the sequential visual isometric pinch force task (SVIPT). After 1 week, the retention of the SVIPT was measured in both groups. We found that the exercise group performed significantly better during initial task acquisition. There were no significant differences in offline memory consolidation between groups, but total skill gain across both acquisition and retention sessions was greater in the group who exercised. The better performance of the exercise group was driven by improvements in accuracy, rather than speed. We have shown that a single bout of moderate intensity aerobic exercise can facilitate motor skill learning in people with HD gene-expansion. More research is needed to investigate the underlying neural mechanisms and to further explore the potential for neurocognitive and functional benefits of exercise for people with HD.

Caffeine Augments the Lactate and Interleukin-6 Response to Moderate-Intensity Exercise.

The release of interleukin (IL)-6 from contracting skeletal muscle is thought to contribute to some of the health benefits bestowed by exercise. This IL-6 response seems proportional to exercise volume and to lactate production. Unfortunately, high volumes of exercise are not feasible for all people. Caffeine augments the magnitude of increase in circulating IL-6 in response to high-intensity and long-duration exercise. Caffeine also increases circulating concentrations of lactate during exercise. We hypothesized that caffeine, ingested before short-duration, moderate-intensity exercise, would lead to greater circulating concentrations of lactate and IL-6 in a study population comprising both male and female individuals. Twenty healthy adults (10 men and 10 women age 25 ± 7 yr (mean ± SD)) completed 30 min of moderate-intensity cycle ergometer exercise, at an intensity corresponding to 60% peak oxygen uptake, after ingesting either caffeine (6 mg·kg -1 ) or placebo. Arterialized-venous blood was collected throughout each of the exercise sessions. Compared with placebo, caffeine increased circulating concentrations of lactate at the end of exercise (5.12 ± 3.67 vs 6.45 ± 4.40 mmol·L -1 , P < 0.001) and after 30 min of inactive recovery (1.83 ± 1.59 vs 2.32 ± 2.09 mmol·L -1 , P = 0.006). Circulating IL-6 concentrations were greatest after 30 min of inactive recovery ( P < 0.001) and higher with caffeine (2.88 ± 2.05 vs 4.18 ± 2.97, pg·mL -1 , P < 0.001). Secondary analysis indicated sex differences; caffeine increased the IL-6 response to exercise in men ( P = 0.035) but not in women ( P = 0.358). In response to moderate-intensity exercise, caffeine evoked greater circulating lactate concentrations in men and women but only increased the IL-6 response to exercise in men. These novel findings suggest that for men unwilling or unable to perform high-intensity and/or long-duration exercise, caffeine may augment the health benefits of relatively short, moderate-intensity exercise.

Use of planar covariation in lower limb kinematics to characterize adaptations of running after cycling in elite triathletes.

To characterize alterations of lower limb intersegmental coordination during the acute phase of running after cycling among highly trained triathletes using an analysis of planar covariation. Nine highly trained triathletes completed a control run (CR) and a run after transitioning from cycling exercise (transition run, or TR condition) on a motorized treadmill at a self-selected pace. Sagittal plane kinematics were recorded using a 3D Vicon motion capture system. Intersegmental coordination of the thigh, shank and foot segments of the right lower limb and run loop planarity were calculated during running before cycling and at four different times after the end of cycling. PCA showed a significant within-subject phase shift of the run loop planarity (F = 6.66, P = 0.01). Post hoc analysis showed significance median differences increase for u 3t parameter between CRSS vs. TR30 (P = 0.01), TRt1/2 (P = 0.01) and TRMRT (P = 0.01). No difference for u 3t parameter existed between CRSS vs. TRSS. Prior variable-cadence, moderate intensity cycling has a significant effect on run loop planarity and therefore intersegmental coordination during the acute transition phase among highly trained triathletes. However, alterations to lower limb coordination are corrected by the 3rd minute after the beginning of the post cycle run. We suggest that planar covariation can be used as a more sensitive measure of cycling-induced variations in running to characterize adaptation in elite and importantly, developing athletes.

Measuring Arterial Oxygen Saturation Using Wearable Devices Under Varying Conditions.

INTRODUCTION: Recently developed wearable monitoring devices can provide arterial oxygen saturation (Spo₂) measurements, offering potential for use in aerospace operations. Pilots and passengers are already using these technologies, but their performance has not yet been established under conditions experienced in the flight environment such as environmental hypoxia and concurrent body motion.METHODS: An initial evaluation was conducted in 10 healthy subjects who were studied in a normobaric chamber during normoxia and at a simulated altitude of 15,000 ft (4572 m; 11.8% oxygen). Spo₂ was measured simultaneously using a standard pulse oximeter and four wearable devices: Apple Watch Series 6; Garmin Fēnix 6 watch; Cosinusso Two in-ear sensor; and Oxitone 1000M wrist-worn pulse oximeter. Measurements were made while stationary at rest, during very slight body motion (induced by very low intensity cycling at 30 W on an ergometer), and during moderate body motion (induced by moderate intensity cycling at 150 W).RESULTS: Missed readings, defined as failure to record an Spo₂ value within 1 min, occurred commonly with all wearables. Even with only very slight body motion, most devices missed most readings (range of 12-82% missed readings) and the rate was higher with greater body motion (range 18-92%). One device tended to under-report Spo₂, while the other devices tended to over-report Spo₂. Performance decreased across the devices when oxygenation was reduced.DISCUSSION: In this preliminary evaluation, the wearable devices studied did not perform to the same standard as a traditional pulse oximeter. These limitations may restrict their utility in flight and require further investigation.Hearn EL, Byford J, Wolfe C, Agyei C, Hodkinson PD, Pollock RD, Smith TG. Measuring arterial oxygen saturation using wearable devices under varying conditions. Aerosp Med Hum Perform. 2023; 94(1):42-47.

Appendix A

INTRODUCTION: Recently developed wearable monitoring devices can provide arterial oxygen saturation (Spo2) measurements, offering potential for use in aerospace operations. Pilots and passengers are already using these technologies, but their performance has not yet been established under conditions experienced in the flight environment such as environmental hypoxia and concurrent body motion. METHODS: An initial evaluation was conducted in 10 healthy subjects who were studied in a normobaric chamber during normoxia and at a simulated altitude of 15,000 ft (4572 m; 11.8% oxygen). SpO2 was measured simultaneously using a standard pulse oximeter and four wearable devices: Apple Watch Series 6; Garmin Fēnix 6 watch; Cosinusso Two in-ear sensor; and Oxitone 1000M wrist-worn pulse oximeter. Measurements were made while stationary at rest, during very slight body motion (induced by very low intensity cycling at 30 W on an ergometer), and during moderate body motion (induced by moderate intensity cycling at 150 W). RESULTS: Missed readings, defined as failure to record an Spo2 value within 1 min, occurred commonly with all wearables. Even with only very slight body motion, most devices missed most readings (range of 12–82% missed readings) and the rate was higher with greater body motion (range 18–92%). One device tended to under-report Spo2, while the other devices tended to over-report Spo2. Performance decreased across the devices when oxygenation was reduced. DISCUSSION: In this preliminary evaluation, the wearable devices studied did not perform to the same standard as a traditional pulse oximeter. These limitations may restrict their utility in flight and require further investigation.

Dietary Nitrate Supplementation Enhances Performance and Speeds Muscle Deoxyhaemoglobin Kinetics during an End-Sprint after Prolonged Moderate-Intensity Exercise.

Short-term dietary nitrate (NO3-) supplementation has the potential to enhance performance during submaximal endurance, and short-duration, maximal-intensity exercise. However, it has yet to be determined whether NO3- supplementation before and during submaximal endurance exercise can improve performance during a short-duration, maximal-intensity end-sprint. In a randomised, double-blind, crossover study, 9 recreationally active men ingested NO3--rich (BR: 8 mmol NO3-/day) and NO3--depleted (PL: 0.75 mmol NO3-/day) beetroot powder for 7 days. On day 7, participants completed 2 h of moderate-intensity cycling, which immediately transitioned into a 60 s maximal-intensity end-sprint, with supplements ingested 2 h before and 1 h into the moderate-intensity exercise bout. Plasma [NO3-] and [NO2-] were higher in BR compared to PL pre- and post-exercise (p &lt; 0.05). Post-exercise plasma [NO3-] was higher than pre-exercise (562 ± 89 µM vs. 300 ± 73 µM; p &lt; 0.05) and plasma [NO2-] was not significantly different pre- (280 ± 58 nM) and post-exercise (228 ± 63 nM) in the BR condition (p &gt; 0.05). Mean power output during the final 30 s of the end-sprint was greater after BR (390 ± 38 W) compared to PL (365 ± 41 W; p &lt; 0.05). There were no differences between BR and PL in any muscle oxygenation variables during moderate-intensity cycling (p &gt; 0.05), but muscle [deoxyhaemoglobin] kinetics was faster during the end-sprint in BR (6.5 ± 1.4 s) compared to PL (7.3 ± 1.4 s; p &lt; 0.05). These findings suggest that NO3- supplementation has the potential to improve end-sprint performance in endurance events when ingested prior to and during exercise.

Feasibility and preliminary effects of exercise interventions on plasma biomarkers of Alzheimer’s disease in the FIT-AD trial: a randomized pilot study in older adults with Alzheimer’s dementia

BackgroundAlzheimer’s disease (AD) biomarkers have provided a unique opportunity to understand AD pathogenesis and monitor treatment responses. However, exercise trials show mixed effects on imagining and cerebrospinal fluid biomarkers of AD. The feasibility and effects of exercise on plasma biomarkers remain unknown. The primary objective of this study was to examine the feasibility of recruitment, retention, and blood sample collection in community-dwelling older adults with mild-to-moderate AD dementia. Secondarily, it estimated the preliminary effects of 6-month aerobic and stretching exercise on plasma amyloid-β42 and Aβ40 (Aβ42/40) ratio, phosphorylated tau (p-tau) 181, and total tau (t-tau).MethodsThis pilot study was implemented in year 2 of the 2-parallel group FIT-AD trial that randomized 96 participants on a 2:1 allocation ratio to moderate-intensity cycling or low-intensity stretching for 20–50 min, 3 times/week for 6 months with 6-month follow-up. Investigators (except for the statistician) and data collectors were blinded to group assignment. Fasting blood samples were collected from 26 participants at baseline and 3 and 6 months. Plasma Aβ42, Aβ40, p-tau181, and t-tau were measured using Simoa™ assays. Data were analyzed using intention-to-treat, Cohen’s d, and linear mixed models.ResultssThe sample averaged 77.6±6.99 years old and 15.4±3.00 years of education with 65% being male and 96.2% being apolipoprotein epsilon 4 gene carriers. The recruitment rate was 76.5%. The retention rate was 100% at 3 months and 96.2% at 6 months. The rate of blood collection was 88.5% at 3 months and 96.2% at 6 months. Means (standard deviation) of within-group 6-month difference in the stretching and cycling group were 0.001 (0.012) and −0.001 (0.010) for Aβ42/40 ratio, 0.609 (1.417) pg/mL and 0.101(1.579) pg/mL for p-tau181, and −0.020 (0.279) pg/mL and −0.075 (0.215) pg/mL for t-tau. Effect sizes for within-group 6-month difference were observed for p-tau181 in stretching (d=0.43 [−0.33, 1.19]) and t-tau in cycling (−0.35 [−0.87, 0.17]).ConclusionsBlood collections with fasting were well received by participants and feasible with high recruitment and retention rates. Plasma biomarkers of AD may be modifiable by exercise intervention. Important design considerations are provided for future Phase III trials.Trials registrationClinicalTrials.gov Identifier: NCT01954550 and posted on October 1, 2013

Longitudinal alterations of pulmonary O2 on-kinetics during moderate-intensity exercise in competitive youth cyclists are related to alterations in the balance between microvascular O2 distribution and muscular O2 utilization.

The main purpose of the current study was to investigate the dynamic adjustment of pulmonary oxygen uptake ( O2) in response to moderate-intensity cycling on three occasions within 15 months in competitive youth cyclists. Furthermore, the muscle Δdeoxy[heme] on-kinetics and the Δdeoxy[heme]-to- O2 ratio were modeled to examine possible mechanistic basis regulating pulmonary O2 on-kinetics. Eleven cyclists (initial age, 14.3 ± 1.6 y; peak O2, 62.2 ± 4.5 mL.min-1.kg-1) with a training history of 2-5 years and a training volume of ~10 h per week participated in this investigation. O2 and Δdeoxy[heme] responses during workrate-transitions to moderate-intensity cycling were measured with breath-by-breath spirometry and near-infrared spectroscopy, respectively, and subsequently modeled with mono-exponential models to derive parameter estimates. Additionally, a normalized Δdeoxy[heme]-to- O2 ratio was calculated for each participant. One-way repeated-measures ANOVA was used to assess effects of time on the dependent variables of the responses. The O2 time constant remained unchanged between the first (~24 s) and second visit (~22 s, P > 0.05), whereas it was significantly improved through the third visit (~13 s, P = 0.006-0.013). No significant effects of time were revealed for the parameter estimates of the Δdeoxy[heme] response (P > 0.05). A significant Δdeoxy[heme]-to- O2 ratio "overshoot" was evident on the first (1.09 ± 0.10, P = 0.006) and second (1.05 ± 0.09, P = 0.047), though not the third (0.97 ± 0.10, P > 0.05), occasion. These "overshoots" showed strong positive relationships with the O2 time constant during the first (r = 0.66, P = 0.028) and second visit (r = 0.76, P = 0.007). Further, strong positive relationships have been observed between the individual changes of the fundamental phase τp and the Δdeoxy[heme]-to- O2 ratio "overshoot" from occasion one to two (r = 0.70, P = 0.017), and two to three (r = 0.74, P = 0.009). This suggests that improvements in muscle oxygen provision and utilization capacity both occurred, and each may have contributed to enhancing the dynamic adjustment of the oxidative "machinery" in competitive youth cyclists. Furthermore, it indicates a strong link between an oxygen maldistribution within the tissue of interrogation and the O2 time constant.

Impact of exercise timing on perceived appetite and food reward in early and late chronotypes: An exploratory study in a male Saudi sample

There is very limited evidence on the influence of diurnal exercise timing on appetite control, and none on food reward or how an individual's chronotype could moderate such effects. We examined the impact of acute exercise timing on perceived appetite and food reward in young Saudi adults with early or late chronotypes. Forty-five young adults (23 ± 4 years; BMI = 25.1 ± 4.0 kg/m2) completed the Morningness–Eveningness Questionnaire (MEQ) and were divided into early (score = 59 ± 5) or late (score = 41 ± 6) chronotypes. Participants attended the laboratory after ≥4 h fast on two occasions for an AM (8:00–10:00) and PM (17:00–19:00) 30-min moderate-intensity cycling bout in a randomized counterbalanced order. Appetite ratings and food reward (Arab Leeds Food Preference Questionnaire) were measured before and after exercise. An acute exercise-induced decrease in hunger was found, which appeared to be dependent upon diurnal timing and chronotype, with hunger being more suppressed after AM exercise in the early chronotypes and after PM exercise in the late chronotypes. There was greater wanting for low-fat sweet foods after AM exercise relative to PM exercise, whereas there was greater wanting for high-fat sweet food and sweet relative to savoury food after PM exercise compared to AM exercise. These preliminary findings suggest that diurnal timing of exercise impacts food preferences, and that chronotype may influence the appetite response to an exercise bout at different times of day.

Blood flow restriction accelerates aerobic training-induced adaptation of {dot{text{V}}}{text{O}}_{2} kinetics at the onset of moderate-intensity exercise

It is unclear whether blood flow restriction (BFR) accelerates the adaptation of the time constant (τ) of phase II oxygen uptake ( {dot{text{V}}}{text{O}}_{2} ) kinetics in the moderate-intensity exercise domain via moderate-intensity aerobic training. Therefore, healthy participants underwent moderate-intensity [45–60% {dot{text{V}}}{text{O}}_{2} Reserve] aerobic cycle training with or without BFR (BFR group, n = 9; CON group, n = 9) for 8 weeks to evaluate {dot{text{V}}}{text{O}}_{2} kinetics during moderate-intensity cycle exercise before (Pre) and after 4 (Mid) and 8 (Post) weeks of training. Both groups trained for 30 min, 3 days weekly. BFR was performed for 5 min every 10 min by applying cuffs to the upper thighs. The τ significantly decreased by Mid in the BFR group (23.7 ± 2.9 s [Pre], 15.3 ± 1.8 s [Mid], 15.5 ± 1.4 s [Post], P < 0.01) and by Post in the CON group (27.5 ± 2.0 s [Pre], 22.1 ± 0.7 s [Mid], 18.5 ± 1.9 s [Post], P < 0.01). Notably, the BFR group’s τ was significantly lower than that of the CON group at Mid (P < 0.01) but not at Post. In conclusion, BFR accelerates the adaptation of the {dot{text{V}}}{text{O}}_{2} kinetics of phase II by moderate-intensity aerobic training.

Effect of recovery time on dot{V}{text{O}}_{2}-ON kinetics in humans at the onset of moderate-intensity cycling exercise

Purposeτ of the primary phase of dot{V}{text{O}}_{{2{text{A}}}} kinetics during square-wave, moderate-intensity exercise mirrors that of PCr splitting (τPCr). Pre-exercise [PCr] and the absolute variations of PCr (∆[PCr]) occurring during transient have been suggested to control τPCr and, in turn, to modulate dot{V}{text{O}}_{{2{text{A}}}} kinetics. In addition, dot{V}{text{O}}_{{2{text{A}}}} kinetics may be slower when exercise initiates from a raised metabolic level, i.e., from a less-favorable energetic state. We verified the hypothesis that: (i) pre-exercise [PCr], (ii) pre-exercise metabolic rate, or (iii) ∆[PCr] may affect the kinetics of muscular oxidative metabolism and, therefore, τ.MethodsTo this aim, seven active males (23.0 yy ± 2.3; 1.76 m ± 0.06, dot{V}{text{O}}_{2max }: 3.32 L min−1 ± 0.67) performed three repetitions of series consisting of six 6-min step exercise transitions of identical workload interspersed with different times of recovery: 30, 60, 90, 120, 300 s.ResultsMono-exponential fitting was applied to breath-by-breath dot{V}{text{O}}_{{2{text{A}}}}, so that τ was determined. τ decays as a first-order exponential function of the time of recovery (τ = 109.5 × e(−t/14.0) + 18.9 r2 = 0.32) and linearly decreased as a function of the estimated pre-exercise [PCr] (τ = − 1.07 [PCr] + 44.9, r2 = 0.513, P < 0.01); it was unaffected by the estimated ∆[PCr].ConclusionsOur results in vivo do not confirm the positive linear relationship between τ and pre-exercise [PCr] and ∆[PCr]. Instead, dot{V}{text{O}}_{{2{text{A}}}} kinetics seems to be influenced by the pre-exercise metabolic rate and the altered intramuscular energetic state.

Evidence that heat acclimation training may alter sleep and incidental activity

ABSTRACT This randomized cross-over study tested the hypothesis that heat acclimation training would detrimentally affect sleep variables and alter incidental physical activity compared to a thermoneutral training control condition. Eight recreationally trained males (V̇O2peak 49±4.9 mL.kg-1.min-1) completed two separate interventions separated by at least 31 days: 5 consecutive day training blocks of moderate-intensity cycling (60 min·day-1 at 50% peak power output) in a hot (34.9±0.7 °C and 53±4 % relative humidity) and a temperate (22.2±2.6 °C; 65±8 % relative humidity) environment. Wrist-mounted accelerometers were worn continuously for the length of the training blocks and recorded physical activity, sleep quality and quantity. Data were analysed in a Bayesian framework, with the results presented as the posterior probability that a coefficient was greater or less than zero. Compared to the temperate training environment, heat acclimation impaired sleep efficiency (Pr β<0 = .979) and wake on sleep onset (Pr β>0 = .917). Daily sedentary time was, on average, 35 min longer (Pr β>0 = .973) and light physical activity time 18 min shorter (Pr β>0 = .960) during the heat acclimation period. No differences were observed between conditions in sleep duration, subjective sleep quality, or moderate or vigorous physical activity. These findings may suggest that athletes and coaches need to be cognisant that heat acclimation training may alter sleep quality and increase sedentary behaviour. Highlights Five consecutive days of heat training negatively affected some objective measures of sleep quality and incidental physical activity in recreationally trained athletes. Athletes and coaches need to be aware of the potential unintended consequences of using heat acclimation on sleep behaviours.

Perceived Exertion Is Elevated By A Dual-task Of Cognitive Performance And Aerobic Exercise

In many sports (e.g., football, lacrosse, rugby, etc.), the need to perform a dual-task (e.g., decision-making during exercise) is unavoidable. Purpose: Given that prolonged continuous performance of a cognitively demanding task increases mental fatigue, we hypothesized that a sustained cognitive effort superimposed during aerobic exercise would compound the increased rating of perceived exertion (RPE). Methods: Twenty-one healthy, young males (aged 22 ± 2 yrs; VO2 peak = 46 ± 5 ml/kg/min) performed two trials [i.e., exercise-cognition (EX-Cog) and exercise-only (EX)] in a randomised-crossover design. In EX-Cog trial, participants performed 50-min moderate-intensity (60% peak oxygen uptake) cycling exercise and sustained 50-min Stroop task, simultaneously. In EX trial, participants performed 50-min moderate-intensity cycling exercise. RPE was assessed via the Borg scale during the final 10 seconds of exercise in both conditions. Mental fatigue (visual analog scale) and heart rate (HR; HR monitor) in response to exercise were also recorded. RPE was analyzed using Wilcoxon signed-rank test. Changes in mental fatigue and HR in response to exercise were analyzed using a two-way (trial × time) repeated-measures analysis of variance. Results: The elevations in mental fatigue and HR were identical during both trials (both P < 0.05). In contrast, RPE was higher during EX-Cog (EX-Cog median 15; IQR 15.0 to 17.0 vs. EX median 15; IQR 14.0 to 16.5, P = 0.012). Conclusions: These findings indicate that dual-tasking increases perceived exertion yet fails to incur additional mental fatigue or cardiovascular demand which may have implications for decision-making during sport.

Effect of cycle ergometer training using different intensities in increasing catecholamine hormone of overweight females

The main purpose of this study was to compare cycle ergometer training using low intensity and moderate intensity in increasing the catecholamine hormone of overweight females. This study was conducted on 50 overweight females with mean age of 22.44±2.97 years old and body mass index between 25 kg.m.2 to 30 kg.m.2. Treatment was given 4 times per week during 5 weeks periods in Group 1 with low intensity cycle ergometer continuous training (60%-70% HRmax), and Group 2 with moderate intensity cycle ergometer continuous training (70%-80% HRmax). Heart rate was monitored using polar heart rate monitor H10. Pre-test was taken before giving treatment and post-test after giving a treatment by taking blood a day after doing exercise and fasting at night and the blood samples obtained are taken to the laboratory for serum sample analysis. Data were analyzed using paired t-test. The result found that there was an increase in catecholamine hormone in both groups with a p-value of &lt;0.05. It can be concluded that cycle ergometer training using low and moderate-intensity improved catecholamine hormone for overweight females.

The Effect of Physical Exercise on Oxidation Capacity and Utero-Placental Circulation in Pregnancies with Gestational Diabetes Mellitus and Uncomplicated Pregnancies, a Pilot Study.

Background: Gestational diabetes mellitus (GDM) is associated with aggravated oxidation capacity and utero-placental circulation, while aerobic exercise could improve both. The study aims to assess oxidation capacity and utero-placental circulation before and after a bout of aerobic exercise in GDM and uncomplicated pregnancies.; Methods: In this cross-sectional study, women with GDM (GDMs) and women with uncomplicated pregnancies(controls), underwent 30 min of moderate intensity cycling. Total antioxidant capacity (TAC), catalase activity (CAT), reduced glutathione (GSH), Uterine Arteries (UtA PI) and Umbilical Artery (UmA PI) pulsatility indexes were estimated prior-to, immediately after and one hour after exercise; Results: In each group, 25 pregnant women were included. In both groups, between prior-to and immediately after exercise, TAC and CAT increased, while GSH decreased, (p < 0.001). In GDMs, CAT was lower than controls at any time point (p < 0.05), while in GDMs delta(Δ) CAT (prior-to and immediately after exercise) was lower than controls (p = 0.003). In GDMs, UtA PI centiles decreased between prior-to and either immediately or one hour after exercise, while they did not change in controls. In GDMs, pre-conceptional BMI and weight gain predicted negatively ΔTAC (prior-to to one hour after exercise); Conclusions: Moderate intensity exercise bout improves oxidation capacity in GDM and uncomplicated pregnancies, although at a lesser extent in the former. Exercise leads to decreased UtA arteries resistance in women with GDM.

Test-retest reliability of lung diffusing capacity for nitric oxide during light to moderate intensity cycling exercise

This study examined test-retest reliability of single-breath lung diffusing capacity for nitric oxide (DLNO) and carbon monoxide (DLCO) during exercise. Sixteen healthy subjects (age 20–67 years) performed DLNO-DLCO tests during light and moderate intensity cycling exercise at 50% and 80% of individual anaerobic threshold (IAT). Primary endpoint was DLNO at 80% IAT. Precision of DLNO, DLCO, and alveolar volume was quantified by within-subject standard deviation (SDws, measurement error) and intraclass correlation coefficients (ICC). Reproducibility was determined by SDws* 2.77. Overall, reliability was excellent for all outcomes. SDws and reproducibility for DLNO at 80% IAT were 4.6 and 12.7 mL.min−1.mmHg−1, and the ICC was 0.99 (95% confidence interval 0.98–0.99). Median breathlessness at 80% IAT was 4 (interquartile range 3–6) on a 0–10 scale. Our data suggest excellent reliability of single-breath DLNO during moderate intensity exercise, but perceived levels of breathlessness may limit its usefulness, especially at exercise intensities beyond IAT.

MitoQ supplementation improves oxygen uptake kinetic by reduced reactive oxygen species levels and altered expression of miR‐155 and miR‐181b

BackgroundMitochondrial antioxidant (MitoQ) has been developed as a pharmaceutical for diseases. Few studies have investigated the role of MitoQ in enhancing athletic performance. Thus, the purpose of the study was to determine the effects of MitoQ supplementation to exercise training (EX) on the oxygen uptake kinetic, oxidative stress, and MicroRNAs (miRNAs) regulating vascular inflammation and reactive oxygen species (ROS) generation.Methods32 healthy young cyclists (25.6±3.8yr) were randomly divided into 4 groups (n=8); 1) Placebo, 2) EX (Cycle ergometer, moderate intensity), 3) MitoQ (20 mg/day, oral), and 4) EX+MitoQ. Oxygen uptake kinetics during low, moderate, and severe intensity cycling were measured before and after two weeks of interventions. Serum levels of ROS, glutathione peroxidase (GPx), and superoxide dismutases (SOD) were measured. miR‐19b, miR‐155, miR‐181b, and miRNA‐146a were measured by RT‐qPCR.ResultsEX+MitoQ accelerated the phase Ⅱ of oxygen uptake kinetic (moderate intensity) compared to EX (P&lt;0.05). Both EX+MitoQ and MitoQ reduced ROS levels but there was no change in EX (P&lt;0.05). GPx was increased in EX, MitoQ, and EX+MitoQ (P&lt;0.05) whereas SOD levels in all groups were not different. miR‐155 and miR‐19b expressions were decreased in EX+MitoQ compared to EX (P&lt;0.05). miR‐146a was increased in EX+MitoQ compared to EX only (P&lt;0.05). There was no difference of miR‐181b between EX and Mito+Q. Placebo effects were not found.ConclusionsA short‐term MitoQ supplementation to aerobic training enhanced oxygen utilization during a moderate performance in cyclists compared to training alone by reduced ROS levels and altered expression of miR‐155 and miR‐181b mediating vascular endothelial inflammation and ROS generation.

Caffeine Augments the Lactate and Interleukin‐6 Response to Moderate‐Intensity Exercise in Men But Not Women

The release of interleukin 6 (IL‐6) from contracting skeletal muscle is thought to contribute to some of the health benefits bestowed by exercise. This IL‐6 response appears proportional to exercise volume. Unfortunately, high volumes of exercise are not feasible for all people. Caffeine augments the magnitude of increase in circulating concentration of IL‐6 in response to high‐intensity and long‐duration exercise, in men. Caffeine is also known to increase circulating concentrations of lactate during exercise. One of the mechanisms thought to contribute to IL‐6 release from exercising skeletal muscle is lactate production. We hypothesized that caffeine, ingested prior to moderate‐intensity exercise, would lead to greater circulating concentrations of lactate and IL‐6 in a study population comprising both men and women. 15 healthy adults (9 males and 6 females, aged 26±7 years, (mean ± SD)) completed 30‐minutes of moderate‐intensity cycle ergometer exercise, equivalent to the ventilatory threshold, after ingesting either caffeine (6 mg/kg) or placebo. Arterialized‐venous blood was collected throughout each of the exercise sessions. Compared with placebo, caffeine increased end‐exercise circulating concentrations of lactate (5.72±3.95 vs. 7.14±4.66 mmol/L, P&lt;0.001) but not end‐exercise IL‐6 (1.84±0.97 vs. 2.37±1.04 pg/mL, P=0.139). However, when women were excluded from the analysis, caffeine augmented (P=0.04) the magnitude of increase of end‐exercise IL‐6 concentration (1.80±0.86 vs. 2.57±1.21 pg/mL); this effect was further exaggerated after 30‐minutes of inactive recovery (3.81±2.32 vs. 5.06±3.22 pg/mL). Noteworthy, caffeine evoked greater end‐exercise lactate concentrations in data sets containing only men (P=0.02) and only women (P=0.002) but did not influence the IL‐6 response in women (P=0.94). Our preliminary data imply that in men unable/unwilling to perform high‐intensity and/or long duration exercise, caffeine may potentially enhance the IL‐6 mediated health benefits of relatively short, moderate intensity exercise.

Sex differences in monocyte CCR2 expression and macrophage polarization following acute exercise

Monocyte chemokine receptor 2 (CCR2) and phosphorylated extra-cellular regulated kinase 1 & 2 (ERK1/2) impact macrophage differentiation and progression of atherosclerosis. Whereas aerobic exercise favorably modulates the immune system and reduces atherosclerotic risk, it is unknown whether sex differences exist in the monocyte/macrophage response to acute aerobic exercise. AimsTo determine the impact of an acute bout of moderate intensity aerobic exercise on monocyte and macrophage CCR2 expression, ERK1/2 phosphorylation, and macrophage polarization in pre-menopausal women and men. Materials and methodsBlood samples were collected in 24 people (Women/Men; n = 12) prior to (PRE), immediately after a bout of moderate intensity cycle ergometry (POST), and 2 h (2H) following exercise. Monocyte and macrophage CCR2 and phosphorylated ERK1/2 as well as macrophage CD86 and CD206 were analyzed by flow cytometry. Key findingsPRE classical monocyte CCR2 expression was greater in women compared to men (Women: 20546.2 ± 2306.4 vs. Men: 14437.6 ± 1201.9 AUF; p = 0.028) and was reduced in women at 2H (PRE: 20546.2 ± 2306.4 vs. 2H: 15856.9 ± 1314.4 AUF; p = 0.027). POST classical monocyte CCR2 expression was inversely associated (r = −0.697, p = 0.012) with POST classical monocyte ERK1/2 phosphorylation in women only. The percentage of CCR2+ macrophages was lower in women at POST (Women: 62.0 ± 8.9 vs. Men: 83.6 ± 3.1; p = 0.031) and at 2H (Women: 60.3 ± 8.4 vs. Men: 83.5 ± 3.0%; p = 0.016). SignificanceThese data suggest that a single bout of moderate intensity aerobic exercise differentially impacts monocyte CCR2 expression and macrophage polarization in women compared to men.