Aerobically Trained Research Articles

Effect of oligosaccharides and aerobic training on hyperglycemia, growth and intestinal microbial diversity of diabetic rats

Abstract Objectives Type 1 diabetes mellitus is a metabolic disease characterized by dysbiosis. Modulation of the gut microbiota by oligosaccharides and aerobic training are proposed mechanisms that ameliorate the disease through affecting host-microbiota interactions. Methods Seventy-two male Wistar rats were randomly divided into 8 groups – 5 with streptozotocin-induced diabetes and 3 healthy controls. The effect of two oligosaccharides – xylo- and galactooligosaccharides, and of aerobic training on the blood glucose concentration, growth and diversity of the gut microbiota was evaluated in the current study. Results The galactooligosaccharides positively affected the glycemic status of the experimental animals as the diabetic and healthy rats had lower blood glucose concentration after 6 weeks of treatment (diabetic rats: week 4 vs. week 8, p=0.047; healthy rats: week 2,4,6,10 vs. week 8, p=0.001, p=0.000, p=0.025 and p=0.001, respectively). A positive effect of the galactooligosaccharides on body weight was observed when administered to diabetic rats in comparison to the diabetic control (p=0.020). Similar results were observed for the aerobically trained diabetic rats (p=0.004). The identification of bacterial species showed preserved microbiota diversity and indicated Bifidobacterium indicum, Lactobacillus feritoshensis and E. coli as the most abundant species among the analyzed genera. Conclusions Prebiotic treatment beneficially affected the hyperglycemia and growth of type 1 diabetic rats. The most significant effect of the aerobic training was the improvement of the morphological parameters. Oligosaccharide administration and exercise did not affect the diversity of the bacterial species.

Calf blood flow is augmented in habitually aerobically trained versus untrained postmenopausal women in association with favorable modulation of vasculo-metabolic interactions.

Menopause is associated with vascular dysfunction and increased risk of developing metabolic syndrome. Associations between vascular and metabolic health, and interactions with aerobic exercise training, are unknown in postmenopausal women (PMW). In habitually aerobically trained PMW (PMWtr; n= 10; 57 ± 1 years; 40 ± 1mL/kg/min), strain-gauge plethysmography was used to compare resting and peak calf blood flow (CBFr and CBFpk, respectively) and vascular resistance (CVRr; CVRpk) versus untrained PMW (PMWun; n= 13; 56 ± 1 years; 29 ± 1mL/kg/min) and premenopausal women (PreM; n= 14; 26 ± 1 years; 40 ± 1mL/kg/min). Vascular measures were taken before and 1 hour after 45 minutes of aerobic exercise (60% V̇ O2peak ), a known nitric oxide stimulus. Blood analyses included low- (LDLc) and high-density lipoprotein cholesterol (HDLc), insulin, and glucose. Pre-exercise, CBFr and CVRr did not differ (p> 0.05) between PMW groups, nor between PreM and PMWtr. CBFpk was highest (p< 0.05) and CVRpk was lowest (p< 0.05) in PMWtr. Blood markers were similar (p> 0.05) in PMW groups. However, in PMWtr, CBFpk was associated inversely (p< 0.05) with insulin (r= -0.725). Conversely, in PMWun, CBFpk correlated (p< 0.05) inversely with glucose (r= -0.717), positively with HDLc (r= 0.633), and CVRpk positively (p< 0.05) with LDLc (r= 0.568). Post-exercise, CBF increased and CVR decreased (p< 0.05) in all groups, yet CBFpk remained higher and CVRpk lower (p< 0.05) in PMWtr. In untrained PMW, peak CBF is associated inversely with circulating pro-atherogenic lipids and glucose. In contrast, peak CBF is associated inversely with insulin levels only in trained PMW. Habitual aerobic exercise may favorably modulate vasculo-metabolic interactions in PMW.

Sex Differences in the Feasibility of Aerobic Exercise Training for Improving Cardiometabolic Health Outcomes in Adults with Type 2 Diabetes

Females with type 2 diabetes (T2D) have a 25-50% greater risk of developing cardiovascular disease compared with males. While aerobic exercise training is effective for improving cardiometabolic health outcomes, there is limited sex-segregated evidence on the feasibility of aerobic training in adults with T2D. A secondary analysis of a 12-week randomized controlled trial examining aerobic training in inactive adults with T2D was conducted. Feasibility outcomes were recruitment, retention, treatment fidelity, and safety. Sex differences and intervention effects were assessed using two-way analyses of variances. Thirty-five participants (14 females) were recruited. The recruitment rate was significantly lower among females (9% versus 18%; p = 0.022). Females in the intervention were less adherent (50% versus 93%; p = 0.016), and experienced minor adverse events more frequently (0.08% versus 0.03%; p = 0.003). Aerobically trained females experienced clinically meaningful reductions in pulse wave velocity (-1.25 m/s, 95%CI [-2.54, 0.04]; p = 0.648), and significantly greater reductions in brachial systolic pressure (-9 mmHg, 95%CI (3, 15); p = 0.011) and waist circumference (-3.8 cm, 95%CI (1.6, 6.1); p < 0.001) than males. To enhance the feasibility of future trials, targeted strategies to improve female recruitment and adherence are needed. Females with T2D may experience greater cardiometabolic health improvements from aerobic training than males.

Aerobic Exercise Ameliorates Myocardial Fibrosis via Affecting Vitamin D Receptor and Transforming Growth Factor-β1 Signaling in Vitamin D-Deficient Mice.

Myocardial fibrosis is a pathological phenomenon associated with cardiovascular disease (CVD) that plays a crucial role in the development of heart diseases. Vitamin D deficiency can promote the development of CVD and exercise plays a role in the treatment of CVD. This study aimed to explore the effects of 12-week aerobic exercise training on myocardial fibrosis in vitamin D-deficient mice. A vitamin D-deficient mouse model was induced by a vitamin D-deficient (0 IU Vitamin D3/kg) diet. Twenty-four C57BL/6J male mice were randomly divided into three groups: a control sedentary group (CONS, n = 8), a vitamin D-deficient sedentary group (VDDS, n = 8), and a vitamin D-deficient exercise group (VDDE, n = 8) which was aerobically trained for 12 weeks. The results showed that the serum 25-hydroxyvitamin D [25(OH)D] levels of the VDDS group were <50 nmol/L, which was significantly lower than that of the CONS group. Compared with the CONS group, the VDDS group showed cardiac dysfunction and significant fibrosis, together with lower vitamin D receptor (VDR) mRNA and protein expression levels, higher mRNA expression levels of profibrotic and inflammatory factors, and higher transforming growth factor-β1 (TGF-β1) and phospho-Smad2/3 (P-Smad2/3) protein expression levels. Serum 25(OH)D levels in the VDDE group were significantly higher than those in the VDDS group. Compared with the VDDS group, the VDDE group showed improved cardiac function and alleviated myocardial fibrosis. Meanwhile, the VDDE group had significantly higher VDR mRNA and protein expression levels; lower mRNA expression levels of profibrotic and inflammatory factors; and lower TGF-β1 and P-Smad2/3 protein expression levels. In conclusion, aerobic exercise training remains a promising intervention for treating myocardial fibrosis in vitamin D deficiency.

Monocarboxylate transporters (MCTs) in skeletal muscle and hypothalamus of less or more physically active mice exposed to aerobic training

AimsThe synthesis of monocarboxylate transporters (MCTs) can be stimulated by aerobic training, but few is known about this effect associated or not with non-voluntary daily activities. We examined the effect of eight weeks of aerobic training in MCTs on the skeletal muscle and hypothalamus of less or more physically active mice, which can be achieved by keeping them in two different housing models, a small cage (SC) and a large cage (LC). Main methodsForty male C57BL/6J mice were divided into four groups. In each housing condition, mice were divided into untrained (N) and trained (T). For 8 weeks, the trained animals ran on a treadmill with an intensity equivalent to 80 % of the individual critical velocity (CV), considered aerobic capacity, 40 min/day, 5 times/week. Protein expression of MCTs was determined with fluorescence Western Blot. Key findingsT groups had higher hypothalamic MCT2 than N groups (ANOVA, P = 0.032). Significant correlations were detected between hypothalamic MCT2 and CV. There was a difference between the SC and LC groups in relation to MCT4 in the hypothalamus (LC > SC, P = 0.044). Trained mice housed in LC (but not SC-T) exhibited a reduction in MCT4 muscle (P < 0.001). SignificanceOur findings indicate that aerobically trained mice increased the expression of MCT2 protein in the hypothalamus, which has been related to the uptake of lactate in neurons. Changes in energy metabolism in physically active mice (kept in LC) may be related to upregulation of hypothalamic MCT4, probably participating in the regulation of satiety.

Mitochondrial Mass of Naïve T Cells Is Associated with Aerobic Fitness and Energy Expenditure of Active and Inactive Adults.

Chronic exercise training is known to induce metabolic changes, but whether these adaptations extend to lymphocytes and how this may affect immune function remains largely unknown. This study was conducted to determine the extent to which mitochondrial characteristics of naïve T cells differ according to fitness status and to further examine the energy production pathways of cells from aerobically trained and inactive participants. Blood was collected from 30 aerobically active (>6 h·wk -1 ) or inactive (<90 min·wk -1 ) men and women. Naïve T cell mitochondrial mass, membrane potential, and biogenesis were assessed with flow cytometry. Participants completed a treadmill maximal oxygen consumption (V̇O 2peak ) test and wore a physical activity monitor for 1 wk. In a subset of participants, naïve CD8 + T cell activation-induced glycolytic and mitochondrial ATP production was measured. Active participants exhibited 16.7% more naïve CD8 + T cell mitochondrial mass ( P = 0.046), 34% greater daily energy expenditure ( P < 0.001), and 39.6% higher relative V̇O 2peak ( P < 0.001), along with 33.9% lower relative body fatness ( P < 0.001). Among all participants, naïve CD8 + T cell mitochondrial mass was correlated with estimated energy expenditure ( r = 0.36, P = 0.048) and V̇O 2peak ( r = 0.47, P = 0.009). There were no significant differences in ATP production, mitochondrial biogenesis, or mitochondrial membrane potential between active and inactive groups. This is the first study to examine the effects of aerobic exercise training status on metabolic parameters within human naïve T cells. Findings suggest that mitochondrial adaptations in certain immune cell types are positively associated with aerobic fitness and energy expenditure. This study provides a foundation for future development of prophylactic and therapeutic interventions targeting specific immune cell subsets to improve the immune response and overall health.

Mechanical and Structural Remodeling of Cardiac Muscle after Aerobic and Resistance Exercise Training in Rats.

Aerobic and resistance exercise training results in distinct structural changes of the heart. The mechanics of how cardiac cells adapt to resistance training and the benefits to cells when combining aerobic and resistance exercise remains largely unknown. The purpose of this study was to compare mechanical adaptations of skinned cardiac fiber bundles after chronic resistance, aerobic and combined exercise training in rats. We hypothesized that differences in mechanical function on the fiber bundle level coincide with differences previously reported in the structure of the heart. Twelve-week-old rats were assigned to (i) an aerobic running group (n = 6), (ii) a ladder climbing resistance group (n = 6), (iii) a combination group subjected to aerobic and resistance training (n = 6), or (iv) a sedentary (control) group (n = 5). Echocardiography was used to measure cardiac structural remodeling. Skinned cardiac fiber bundles were used to determine active and passive force properties, maximal shortening velocity, and calcium sensitivity. Aerobically trained animals had 43%-49% greater ventricular volume and myocardial thickness, and a 4%-17% greater shortening velocity and calcium sensitivity compared with control group rats. Resistance-trained rats had 37%-71% thicker ventricular walls, a 56% greater isometric force production, a 9% greater shortening velocity, and a 4% greater calcium sensitivity compared with control group rats. The combination exercise-trained rats had 25%-43% greater ventricular volume and myocardial wall thickness, a 55% greater active force production, a 7% greater shortening velocity, and a 60% greater cross-bridge cooperativity compared with control group rats. The heart adapts differently to each exercise modality, and a combination of aerobic and resistance training may have the greatest benefit for cardiac health and performance.

Aerobic exercise and aerobic fitness level do not modify motor learning

Motor learning may be enhanced when a single session of aerobic exercise is performed immediately before or after motor skill practice. Most research to date has focused on aerobically trained (AT) individuals, but it is unknown if aerobically untrained (AU) individuals would equally benefit. We aimed to: (a) replicate previous studies and determine the effect of rest (REST) versus exercise (EXE) on motor skill retention, and (b) explore the effect of aerobic fitness level (AU, AT), assessed by peak oxygen uptake (VO2peak), on motor skill retention after exercise. Forty-four participants (20–29 years) practiced a visuomotor tracking task (acquisition), immediately followed by 25-min of high-intensity cycling or rest. Twenty-four hours after acquisition, participants completed a motor skill retention test. REST and EXE groups significantly improved motor skill performance during acquisition [F(3.17, 133.22) = 269.13, P = 0.001], but had no group differences in motor skill retention across time. AU-exercise (VO2peak = 31.6 ± 4.2 ml kg−1 min−1) and AT-exercise (VO2peak = 51.5 ± 7.6 ml kg−1 min−1) groups significantly improved motor skill performance during acquisition [F(3.07, 61.44) = 155.95, P = 0.001], but had no group differences in motor skill retention across time. Therefore, exercise or aerobic fitness level did not modify motor skill retention.

Midlife aerobic exercise and brain structural integrity: Associations with age and cardiorespiratory fitness

Lower midlife physical activity is associated with higher risk of neurodegenerative disease in late life. However, it remains unknown whether physical exercise and fitness are associated with brain structural integrity during midlife. The purpose of this study was to compare brain structures between middle-aged aerobically trained adults (MA), middle-aged sedentary (MS), and young sedentary (YS) adults. Thirty MA (54±4 years), 30 MS (54±4 years), and 30 YS (32±6 years) participants (50% women) underwent measurements of brain volume, cortical thickness, and white matter (WM) fiber integrity using MRI. MA participants had aerobic training for 24.8±9.6 years and the highest cardiorespiratory fitness level (i.e., peak oxygen uptake: VO2peak) among all groups. Global WM integrity, as assessed with fractional anisotropy (FA) from diffusion tensor imaging, was lower in the MS compared with the YS group. However, global FA in the MA group was significantly higher than that in the MS group (P<0.05) and at a similar level to the YS group. Furthermore, tract-based spatial statistical analysis demonstrated that FA in the anterior, superior, and limbic WM tracts (e.g., the genu of the corpus callosum, superior longitudinal fasciculus, uncinate fasciculus) was higher in the MA compared with MS groups, and positively associated with VO2peak, independently from age and sex. From cortical thickness analysis, MS and MA participants showed thinner prefrontal and parieto-temporal areas than the YS group. On the other hand, the MA group exhibited thicker precentral, postcentral, pericalcarine, and lateral occipital cortices than the MS and YS groups. But, the insula and right superior frontal gyrus showed thinner cortical thickness in the MA compared with the MS groups. Collectively, these findings suggest that midlife aerobic exercise is associated with higher WM integrity and greater primary motor and somatosensory cortical thickness.

Aerobic exercise training regulates serum extracellular vesicle miRNAs linked to obesity to promote their beneficial effects in mice.

There is a growing body of evidence that extracellular vesicles (EVs) and their cargo of RNA, DNA, and protein are released in the circulation with exercise and might mediate interorgan communication. C57BL6/J male mice were subjected to diet-induced obesity and aerobic training on a treadmill for 8 wk. The effect of aerobic training was evaluated in the liver, muscle, kidney, and white/brown adipose tissue. To provide new mechanistic insight, we profiled miRNA from serum EVs of obese and obese trained mice. We demonstrate that aerobic training changes the circulating EV miRNA profile of obese mice, including decreases in miR-122, miR-192, and miR-22 levels. Circulating miRNA levels were associated with miRNA levels in mouse liver white adipose tissue (WAT). In WAT, aerobically trained obese mice showed reduced adipocyte hypertrophy and increased the number of smaller adipocytes and the expression of Cebpa, Pparg, Fabp4 (adipogenesis markers), and ATP-citrate lyase enzyme activity. Importantly, miR-22 levels negatively correlated with the expression of adipogenesis and insulin sensitivity markers. In the liver, aerobic training reverted obesity-induced steatohepatitis, and steatosis score and Pparg expression were negatively correlated with miR-122 levels. The prometabolic effects of aerobic exercise in obesity possibly involve EV miRNAs, which might be involved in communication between liver and WAT. Our data provide significant evidence demonstrating that aerobic training exercise-induced EVs mediate the effect of exercise on adipose tissue metabolism.

Aerobic Recovery Of A 65-year Old Following Radical Prostatectomy

Following radical prostatectomy, patients are generally advised to engage in no strenuous exercise for 4-6 weeks. Beyond that time range, the rapidity with which a patient may return to high-level aerobic activity is not known. PURPOSE: To examine the recovery following radical prostatectomy (RP) of an endurance-trained 65-year old man with localized prostate cancer and single-vessel heart disease. METHODS: A maximal incremental exercise test and a one-hour steady-state test were performed just prior to and three months following robotic RP to determine maximal oxygen consumption (VO2max) and other cardiorespiratory variables. The patient recorded his training as he prepared for an endurance event that was to occur three months after RP, the Norwegian Foot March (NFM), a 30-km road march carrying 11.4 kg. RESULTS: In the month prior to RP, the patient performed 2-3 hours of vigorous-intensity aerobic exercise per week, fast walking carrying an 11.4-kg pack, with the longest individual session being a 16-km road march. Just prior to surgery, VO2max was 36.7 mL.min-1.kg-1, heart rate during 30 min at 7.2 km.hr-1 and 0% grade was 77% of heart rate reserve (HRR), and during 30 min at 5.3 km.hr-1 and 10% grade was 92% HRR. On post-surgery day 44, he did a 19-km road march carrying 11.4 kg, exceeding the training level of the month pre-surgery. Three months post-surgery, VO2max was 42.7 mL.min-1.kg-1, and heart rates during the flat and uphill 30-min sessions at the same absolute-intensity as pre-surgery were 70% and 83% HRR, respectively. He completed the NFM 93 days post-surgery in 4:24:37, with an average heart rate of 72% HRR. CONCLUSIONS: This case study demonstrates that an aerobically trained prostate cancer patient can return to high-level aerobic training in as little as seven weeks post-radical prostatectomy, and even exceed pre-surgery fitness. This finding has implications for prognosis given the beneficial effect of vigorous-intensity exercise on prostate cancer progression.

The Effect of High Intensity Interval Training Versus Steady State Aerobic Training on Skin Microvascular Reactivity in Moderately Active Young Adults: A Pilot Study

A sedentary lifestyle is associated with endothelial dysfunction, leading to vascular pathology and impaired microvascular reactivity (MVR). Enhanced endothelial functioning has been seen in aerobically trained individuals. The purpose of this study was to determine if there was a differential training response of skin MVR in response to high intensity aerobic interval training (HIAIT) as compared to steady state aerobic training (SSAT). The study involved 16 moderately active male students (age: 20.93 &amp;plusmn; 5.05 yrs). They were randomly assigned to one of three groups; HIAIT, SSAT, and control group (CG). Baseline testing was performed to determine the VO2max, lactate threshold, blood pressure, body composition and a post-occlusive reactive hyperemia response (PORH) test was used to assess microvascular reactivity on the right palmer forearm using a moorVMS-Laser Doppler Flowmetry (LDF) These parameters were reassessed after three weeks (mid-point) and six-weeks (post intervention) weeks. Statistical significance was set at p&amp;le;0.05. There were no significant interactions between the variables measured in the three groups over time. There was a positive linear relationship in the SSAT group for PORHmax/time to peak (Tp) at baseline (r = 0.998, p = 0.039), midpoint (r = 0.992, p = 0.083), and the post intervention (r = 0.987, p = 0.103). Training in the SSAT group had improved PORHpeak at midpoint and post intervention time points (r = 0.999, p = 0.22; r = 1, p = 0.006; r = 1, p = 0.011). Training in either the HIAIT or the SSAT group had no significant effect on skin MVR in moderately active young adults. SSAT did display a positive linear relationship with PORHmax/Tp, and PORHpeak, which are variables influencing skin MVR.

Microparticle Responses to Aerobic Exercise and Meal Consumption in Healthy Men.

Microparticles (MP) are shed extracellular vesicles that express the prothrombotic tissue factor (TF). Aerobic exercise may reduce MP count and TF expression. This study investigated the impact of acute running or rest followed by standardized meal consumption on MP phenotypes and TF expression. Fifteen males (age, 22.9 ± 3.3 yr; body mass, 81.9 ± 11.4 kg; V˙O2max, 54.9 ± 6.5 mL·kg·min; mean ± SD) completed 1 h of running (70% V˙O2max) or rest at 9:00 AM and consumed a standardized meal (1170 kcal, 43% CHO, 17% PRO, 40% fat) at 10:45 AM. Venous blood samples were taken at 9:00 AM, 10:00 AM, and 11:30 AM. The MP concentration, diameter, phenotypes, and TF expression were assessed using nanoparticle tracking analysis and flow cytometry. Nanoparticle tracking analysis identified no changes in MP concentration or diameter in response to time or trial. Flow cytometry revealed total MP count increased from 9:00 AM to 10:00 AM (1.62 ± 2.28 to 1.74 ± 2.61 × 10 L, P = 0.016, effect size (η) = 0.105), but was unaffected by trial. TF platelet-derived MP % reduced from 9:00 AM to 10:00 AM (44.0% ± 21.2% to 21.5% ± 9.3%, P = 0.001, η = 0.582) after exercise only (control, 36.8% ± 18.2% to 34.9% ± 11.9%; P = 0.972). TF neutrophil-derived MP percentage reduced from 9:00 AM to 11:30 AM (42.3% ± 17.2% to 25.1% ± 14.9%; P = 0.048, η = 0.801) in the exercise trial only (control, 28.5% ± 15.7% to 32.2% ± 9.6%; P = 0.508). Running induced a significant reduction in %TF platelet and neutrophil MP, suggesting a transient reduction in cardiovascular risk via reduced TF-stimulated thrombosis. This requires further investigation over longer periods in cardiovascular disease populations.

Exercise Training Plus Sildenafil Treatment: Role on Autonomic and Inflammatory Markers.

The current study aimed to determine the effects of sildenafil-associated aerobic exercise training (ET) on the physical performance, hemodynamic, autonomic and inflammatory parameters of rats. Male Wistar rats were randomly assigned to: sedentary rats placebo-treated (SP); sedentary rats sildenafil-treated (SS); trained rats placebo-treated (TP); and trained rats sildenafil-treated (TS). Sildenafil treatment consisted of 8 weeks of daily oral gavage (1.5 mg/kg), one hour before the session of ET (60-75% of maximal running speed, 5 days/week, for 8 weeks). After ET period, physical capacity, hemodynamic, autonomic and skeletal muscle inflammatory profile were assessed. Chronic sildenafil treatment causes an additional increase of physical capacity in aerobically trained rats. However, these beneficial effects were accompanied by unwanted alterations, as increased of arterial pressure and peripheral sympathetic modulation, as well as exacerbated inflammatory status on skeletal muscle of rats. Taken together, these data suggest the positive and negative effects of sildenafil chronic administration, associated to aerobic ET, at doses used in clinical practice. This report stresses the importance of paying greater attention to the indiscriminate use of this substance in high-performance sports.

Does the acute hemodynamic response to a maximum running exercise depend on the aerobic training status of the subjects?

BackgroundHigh-intensity training has become increasingly popular in recent years but the exact effects of high intensity running on the hemodynamic system are not entirely understood and it is unknown whether the aerobic training status of the subjects might influence these hemodynamic reactions. Therefore, the study aims to evaluate whether the acute reactions of peripheral and central blood pressure (BP) and arterial stiffness (AS) to a maximal running exercise depend the training status of the subjects. Methods41 healthy subjects were recruited. Of these were 21 aerobically trained (AE; 11 men) and 20 untrained (UN; 10 men). Aortic pulse wave velocity (PWV), peripheral and central BP was measured at rest and immediately after a maximal treadmill exercise using a ramp protocol including spirometric measurements. ResultsResting hemodynamic values were not different between the groups. Systolic central and peripheral BP, and PWV increased in both groups in response to the running exercise. Δ of all measured parameters showed no difference between the groups. ConclusionsThe acute increases of AS and BP to a maximal running regimen seem to be independent of the subjects’ training status and might therefore be an eligible training mode to maintain overall and vascular health.

Aerobic fitness alters the capacity of mononuclear cells to produce pentraxin 3 following maximal exercise.

Pentraxin 3 (PTX3) is a vital regulator of innate immune function. Although plasma PTX3 concentrations are elevated with aerobic fitness, the cellular functions of PTX3 remain unknown in aerobically trained and untrained subjects. Thirty individuals (aerobically trained = 15 and untrained = 15) participated in a maximal exercise protocol to examine ex vivo PTX3 production from isolated peripheral blood mononuclear cells (PBMCs) exposed to LPS or palmitate. The capacity of PTX3 to stimulate inflammatory cytokine production ex vivo was also examined. Elevated plasma PTX3 concentrations prior to exercise were positively associated with the percent change (pre to post exercise) in plasma PTX3 concentrations in all subjects, independent of cardiorespiratory fitness (VO2max). In addition, elevated plasma PTX3 concentrations in aerobically trained subjects at rest predicted changes in the LPS- and palmitate-stimulated PTX3 production from isolated PBMCs following acute exercise. In response to PTX3 simulation, the capacity of PBMCs to produce the anti-inflammatory cytokine IL-10 was decreased following acute exercise in all subject (no changes in IL-6, TGF-β1, and TNF-α observed). However, the percent change in IL-6 production was positively associated with VO2max in all subjects, and in aerobicallytrained subjects only, positively associated with elevated plasma PTX3 concentrations at rest and in response to acute exercise. These results suggest that aerobic training enhances the utilization of plasma PTX3 concentrations to predict the capacity of mononuclear cells to produce PTX3, and potentially, its reciprocal role of PTX3 as an initiator of the innate immune response following maximal exercise.

Heart Rate Responses in the Diving Reflex among Aerobically Trained and Untrained Men

The mechanisms of the diving reflex involve the simultaneous activation of the sympathetic and parasympathetic nervous systems (PNS). The enhanced PNS capabilities as achieved through aerobic training has been investigated in the diving reflex, specifically vagally-mediated bradycardia, and the research remains controversial. PURPOSE: The current study was conducted to evaluate heart rate responses associated with the diving reflex in aerobically trained and untrained men. METHODS: Using 2 x 3 mixed factorial ANOVA, lowest heart rate achieved, percent heart rate reduction, and time course of heart rate reduction were compared between aerobically untrained (n = 7) and trained (n = 9) men while breath holding in air, water at 15 °C, and water at 0 °C. RESULTS: Results showed that trained men did not differ in percent heart rate reduction or lowest heart rate achieved, although there was a tendency for lowest heart rate achieved in the trained group (p = .06). A significant interaction was found for time course (p = .01), where trained men took significantly longer to reach a plateau in heart rate in the air compared to untrained men. No differences in training status were found for time course in the two water conditions. However, a linear increase in time course for untrained men in the water conditions indicated a potentially delayed response by the PNS with the diving reflex. CONCLUSION: No additional clarification on the impact of training status on the diving reflex has been made except that an effect may lie in the timing of the response of the PNS.

Body Sweat Mapping of Untrained Males during Exercise-Induced Hyperthermia

Aerobic training increases gross and regional sweating rates (RSR) allowing improved evaporative heat loss. Variation in RSR are widely recognized, but limited RSR data and implications for thermoregulation are available in untrained individuals. PURPOSE: Our aim was to investigate RSR and distribution at 35 sites in young, untrained males (UT) versus endurance-trained male athletes (TR) during exercise-induced hyperthermia in a moderate environment. METHODS: Six young, healthy, untrained males (22 ± 3 yrs, VO2max 42.7 ± 7.2 ml.kg-1.min-1) and nine aerobically trained male athletes (23 ± 3 yrs, VO2max 70.2 ± 13 ml.kg-1.min-1) ran for 60 minutes in 25.6 ± 4.5°C, 48.5 ± 0.5% relative humidity, and a 1 m.s-1 air velocity. RSR were measured at two exercise intensities (I1, 60% VO2max; I2, 75% VO2max) using a modified absorbent technique. RESULTS: Core temperature was similar between groups at all stages (P>0.05). GSL was significantly higher in TR versus UT at I1 and I2 (I1: TR 365 ± 84, UT 157 ± 66 g.m-2.h-1, P<0.001; I2 TR 657 ± 119, UT 311 ± 93 g.m-2.h-1, p<0.001), reflecting a significantly higher absolute work rate in TR versus UT (p<0.01). Absolute RSR were significantly higher in TR versus UT at 28 of 35 regions at I1 and 31 out of 35 regions at I2. Highest RSR were observed on the central mid back in both groups (I1 TR 797 ± 250, UT 277 ± 120 g.m-2.h-1; I2 TR 1139 ± 364, UT 365 ± 148 g.m-2.h-1), with lowest values on the palms in TR (I1 98 ± 58, I2 126 ± 53, g.m-2.h-1) and anterior upper arms in UT (I1 33 ± 24, I2 71 ±30 g.m-2.h-1). Both groups showed a medial to lateral decrease in RSR on the posterior torso, and proximal to distal increase on the arms. Normalized ratio values were significantly different between groups at 4 and 6 sites out of 35 at I1 and I2, respectively, none of which were significant following Bonferroni correction. No correlation was observed between RSR and local skin temperature in either group. CONCLUSIONS: These data provide the most detailed exercise-induced RSR for untrained males, showing large RSR variation. Despite significant differences in GSL and absolute RSR, normalized data suggest no significant differences in distribution of sweat between groups. Male athletes demonstrated superior thermoregulation, with similar Tcore and Tsk values despite a higher absolute workload. Funded by the Adidas Innovation Team.

Effects of Resistance Training on Vascular and Hemodynamic Responses to Standardized Workloads in Coronary Patients

PURPOSE: To determine the impact of superimposed resistance training (RT) in aerobically trained coronary patients on systolic blood pressure (SBP), heart rate (HR), rating of perceived exertion (RPE; 6-20 scale), and rate pressure product (RPP) at fixed submaximal workloads following a 12-week RT intervention. Additionally, pre and post RT measures of brachial artery reactivity, an index of endothelial function, were obtained. METHODS: Fifteen low risk coronary patients (13 men, 2 women; mean ± SD age = 66.1 ± 5.1yrs) completed a progressive 12-week RT program that complemented their regular aerobic training regimen. Prior to training, SBP, HR, RPP, and RPE were obtained while subjects performed 1 set (10 repetitions) of 3 different exercises (bicep curl [BC], shoulder press [SP], leg press [LP]) at an intensity ~ 60-80% of 1-repetition maximum. After the training period, testing was repeated while subjects lifted the identical pre-training loads for each exercise following a standardized protocol. Vascular function was assessed by flow-mediated vasodilation (FMD) testing prior to and immediately following the 12-week RT training intervention. RESULTS: Lifting the same pre-training loads evoked attenuated responses for all variables (HR, SBP, RPE, RPP). A statistically significant decrease was shown for RPP ([HR x SBP]/100) during BC (106 ± 27 to 91 ± 22, P < 0.007) and SP (102 ± 24 to 86 ± 17, P < 0.007), whereas the RPP decrease during LP (116±22 to 109 ± 26) did not achieve statistical significance (P = 0.18). RPE for all 3 exercises decreased significantly (P < 0.0001) following the RT intervention: BC (14.3 ± 2.3 to 9.7 ± 1.6), SP (13.9 ± 1.6 to 9.2 ± 1.5), LP (14.3 ± 1.4 to 10.3 ± 1.6). Pre versus post RT measurements for resting HR and resting SBP were unchanged. Peak FMD responses for the 15 subjects were 12.8% and 10.3% dilation pre- and post-training, respectively (P = 0.332). However, 5 of the 15 subjects showed modest improvements in their post-training time to achieve maximum dilation from a mean of 117 seconds to 81 seconds (P = 0.156). CONCLUSION: Among aerobically trained coronary patients, a superimposed resistance training program resulted in decreased hemodynamic and RPE responses to lifting fixed submaximal workloads and improved FMD responses in 5 of the 15 participants.

The Effect of Being Aerobically Active vs. Inactive on Cutaneous Vascular Conductance during Local Heat Stress in an Older Population.

Objective: To test the hypothesis that long- term aerobically trained elderly individuals have a greater amount of bioavailable nitric oxide (NO) and have a larger cutaneous vasodilation during local heat stress compared to their inactive elderly counterparts.Methods: Eight aerobically trained and 8 inactive older men (>60 years old) participated in this study. NO bioavailability in blood and intradermal dialysate were measured with an ozone based chemiluminescence NO analyzer. Cutaneous vasodilator response to local heating was obtained using laser Doppler velocimetry.Results: Whole blood NO were similar in older- trained and inactive subjects (0.75 ± 0.56 and 0.38 ± 0.32 μM, respectively; Mann–Whitney, p = 0.153), as was intradermal dialysate NO before (7.82 ± 6.32 and 4.18 ± 1.89 μM, respectively) and after local heating (7.16 ± 6.27 and 5.88 ± 3.97 μM, respectively, p = 0.354). The cutaneous vasodilator response of the older- inactive group was smaller than the older- trained group [Group-Time interaction, F(24, 264) = 12.0, p < 0.0001]. When compared to a young group the peak vasodilator response of the older- trained subjects was similar. However, the time to initial dilation was 3.1 and 2.2 times longer (p < 0.05) in older- inactive and older- trained subjects, respectively, compared to young subjects.Conclusions: Our data support the hypothesis that the age-related reductions in cutaneous vasodilation can possibly be restored by maintaining an aerobic training regimen (at least 3 years). However, some residual effects of aging remain, specifically a delayed cutaneous vasodilator response to local heating is still present in active older adults. We found no evidence for an increase in systemic or local NO-bioavailability with an extended commitment to aerobic fitness.