Protective effects of aerobic exercise on acute lung injury induced by LPS in mice

Abstract Introduction The regular practice of physical exercise has been associated with beneficial effects on various pulmonary conditions. We investigated the mechanisms involved in the protective effect of exercise in a model of lipopolysaccharide (LPS)-induced acute lung injury (ALI). Methods Mice were divided into four groups: Control (CTR), Exercise (Exe), LPS, and Exercise + LPS (Exe + LPS). Exercised mice were trained using low intensity daily exercise for five weeks. LPS and Exe + LPS mice received 200 µg of LPS intratracheally 48 hours after the last physical test. We measured exhaled nitric oxide (eNO); respiratory mechanics; neutrophil density in lung tissue; protein leakage; bronchoalveolar lavage fluid (BALF) cell counts; cytokine levels in BALF, plasma and lung tissue; antioxidant activity in lung tissue; and tissue expression of glucocorticoid receptors (Gre). Results LPS instillation resulted in increased eNO, neutrophils in BALF and tissue, pulmonary resistance and elastance, protein leakage, TNF-alpha in lung tissue, plasma levels of IL-6 and IL-10, and IL-1beta, IL-6 and KC levels in BALF compared to CTR (P ≤0.02). Aerobic exercise resulted in decreases in eNO levels, neutrophil density and TNF-alpha expression in lung tissue, pulmonary resistance and elastance, and increased the levels of IL-6, IL-10, superoxide dismutase (SOD-2) and Gre in lung tissue and IL-1beta in BALF compared to the LPS group (P ≤0.04). Conclusions Aerobic exercise plays important roles in protecting the lungs from the inflammatory effects of LPS-induced ALI. The effects of exercise are mainly mediated by the expression of anti-inflammatory cytokines and antioxidants, suggesting that exercise can modulate the inflammatory-anti-inflammatory and the oxidative-antioxidative balance in the early phase of ALI.

Aerobic exercise training induces metabolic benefits in rats with metabolic syndrome independent of dietary changes

OBJECTIVES: We evaluated the effects of aerobic exercise training without dietary changes on cardiovascular and metabolic variables and on the expression of glucose transporter Type 4 in rats with metabolic syndrome. METHODS: Twenty male spontaneously hypertensive rats received monosodium glutamate during the neonatal period. The animals were allocated to the following groups: MS (sedentary metabolic syndrome), MS-T (trained on a treadmill for 1 hour/day, 5 days/week for 10 weeks), H (sedentary spontaneously hypertensive rats) and H-T (trained spontaneously hypertensive rats). The Lee index, blood pressure (tail-cuff system), insulin sensitivity (insulin tolerance test) and functional capacity were evaluated before and after 10 weeks of training. Glucose transporter Type 4 expression was analyzed using Western blotting. The data were compared using analysis of variance (ANOVA) (p<0.05). RESULTS: At baseline, the MS rats exhibited lower insulin sensitivity and increased Lee index compared with the H rats. Training decreased the body weight and Lee index of the MS rats (MS-T vs. MS), but not of the H rats (H-T vs. H). There were no differences in food intake between the groups. At the end of the experiments, the systolic blood pressure was lower in the two trained groups than in their sedentary controls. Whole-body insulin sensitivity increased in the trained groups. Glucose transporter Type 4 content increased in the heart, white adipose tissue and gastrocnemius muscle of the trained groups relative to their respective untrained groups. CONCLUSION: In conclusion, the present study shows that an isolated aerobic exercise training intervention is an efficient means of improving several components of metabolic syndrome, that is, training reduces obesity and hypertension and increases insulin sensitivity

Impact of aerobic exercise capacity and procedure-related factors in lung cancer surgery

Over the past decades, major progress in patient selection, surgical techniques and anaesthetic management have largely contributed to improved outcome in lung cancer surgery. The purpose of this study was to identify predictors of post-operative cardiopulmonary morbidity in patients with a forced expiratory volume in 1 s <80% predicted, who underwent cardiopulmonary exercise testing (CPET). In this observational study, 210 consecutive patients with lung cancer underwent CPET with completed data over a 9-yr period (2001-2009). Cardiopulmonary complications occurred in 46 (22%) patients, including four (1.9%) deaths. On logistic regression analysis, peak oxygen uptake (peak V'(O₂) and anaesthesia duration were independent risk factors of both cardiovascular and pulmonary complications; age and the extent of lung resection were additional predictors of cardiovascular complications, whereas tidal volume during one-lung ventilation was a predictor of pulmonary complications. Compared with patients with peak V'(O₂) >17 mL·kg⁻¹·min⁻¹, those with a peak V'(O₂) <10 mL·kg⁻¹·min⁻¹ had a four-fold higher incidence of cardiac and pulmonary morbidity. Our data support the use of pre-operative CPET and the application of an intra-operative protective ventilation strategy. Further studies should evaluate whether pre-operative physical training can improve post-operative outcome.

The effect of increased lipid intake on hormonal responses during aerobic exercise in endurance-trained men

In view of the growing health problem associated with obesity, clarification of the regulation of energy homeostasis is important. Peripheral signals, such as ghrelin and leptin, have been shown to influence energy homeostasis. Nutrients and physical exercise, in turn, influence hormone levels. Data on the hormonal response to physical exercise (standardized negative energy balance) after high-fat (HF) or low-fat (LF) diet with identical carbohydrate intake are currently not available. The aim of the study was to investigate whether a short-term dietary intervention with HF and LF affects ghrelin and leptin levels and their modulators, GH, insulin and cortisol, before and during aerobic exercise. Eleven healthy, endurance-trained male athletes (W(max) 365 +/- 29 W) were investigated twice in a randomized crossover design following two types of diet: 1. LF - 0.5 g fat/kg body weight (BW) per day for 2.5 days; 2. HF - 0.5 g fat/kg BW per day for 1 day followed by 3.5 g fat/kg BW per day for 1.5 days. After a standardized carbohydrate snack in the morning, metabolites and hormones (GH, ghrelin, leptin, insulin and cortisol) were measured before and at regular intervals throughout a 3-h aerobic exercise test on a cycloergometer at 50% of W(max). Diet did not significantly affect GH and cortisol concentrations during exercise but resulted in a significant increase in ghrelin and decrease in leptin concentrations after LF compared with HF diet (area under the curve (AUC) ghrelin LF vs HF: P < 0.03; AUC leptin LF vs HF: P < 0.02, Wilcoxon rank test). These data suggest that acute negative energy balance induced by exercise elicits a hormonal response with opposite changes of ghrelin and leptin. In addition, the hormonal response is modulated by the preceding intake of fat.

The effect of aerobic exercise on intrahepatocellular and intramyocellular lipids in healthy subjects

BACKGROUND Intrahepatocellular (IHCL) and intramyocellular (IMCL) lipids are ectopic lipid stores. Aerobic exercise results in IMCL utilization in subjects over a broad range of exercise capacity. IMCL and IHCL have been related to impaired insulin action at the skeletal muscle and hepatic level, respectively. The acute effect of aerobic exercise on IHCL is unknown. Possible regulatory factors include exercise capacity, insulin sensitivity and fat availability subcutaneous and visceral fat mass). AIM To concomitantly investigate the effect of aerobic exercise on IHCL and IMCL in healthy subjects, using Magnetic Resonance spectroscopy. METHODS Normal weight, healthy subjects were included. Visit 1 consisted of a determination of VO2max on a treadmill. Visit 2 comprised the assessment of hepatic and peripheral insulin sensitivity by a two-step hyperinsulinaemic euglycaemic clamp. At Visit 3, subcutaneous and visceral fat mass were assessed by whole body MRI, IHCL and IMCL before and after a 2-hours aerobic exercise (50% of VO(2max)) using ¹H-MR-spectroscopy. RESULTS Eighteen volunteers (12M, 6F) were enrolled in the study (age, 37.6±3.2 years, mean±SEM; VO(2max), 53.4±2.9 mL/kg/min). Two hours aerobic exercise resulted in a significant decrease in IMCL (-22.6±3.3, % from baseline) and increase in IHCL (+34.9±7.6, % from baseline). There was no significant correlation between the exercise-induced changes in IMCL and IHCL and exercise capacity, subcutaneous and visceral fat mass and hepatic or peripheral insulin sensitivity. CONCLUSIONS IMCL and IHCL are flexible ectopic lipid stores that are acutely influenced by physical exercise, albeit in different directions. TRIAL REGISTRATION ClinicalTrial.gov NCT00491582.

Aerobic exercise but not resistance exercise reduces intrahepatic lipid content and visceral fat and improves insulin sensitivity in obese adolescent girls: a randomized controlled trial

It is unclear whether regular exercise alone (no caloric restriction) is a useful strategy to reduce adiposity and obesity-related metabolic risk factors in obese girls. We examined the effects of aerobic (AE) vs. resistance exercise (RE) alone on visceral adipose tissue (VAT), intrahepatic lipid, and insulin sensitivity in obese girls. Forty-four obese adolescent girls (BMI ≥95th percentile, 12-18 yr) with abdominal obesity (waist circumference 106.5 ± 11.1 cm) were randomized to 3 mo of 180 min/wk AE (n = 16) or RE (n = 16) or a nonexercising control group (n = 12). Total fat and VAT were assessed by MRI and intrahepatic lipid by proton magnetic resonance spectroscopy. Intermuscular AT (IMAT) was measured by CT. Insulin sensitivity was evaluated by a 3-h hyperinsulinemic (80 mU·m(2)·min(-1)) euglycemic clamp. Compared with controls (0.13 ± 1.10 kg), body weight did not change (P > 0.1) in the AE (-1.31 ± 1.43 kg) and RE (-0.31 ± 1.38 kg) groups. Despite the absence of weight loss, total body fat (%) and IMAT decreased (P < 0.05) in both exercise groups compared with control. Compared with control, significant (P < 0.05) reductions in VAT (Δ-15.68 ± 7.64 cm(2)) and intrahepatic lipid (Δ-1.70 ± 0.74%) and improvement in insulin sensitivity (Δ0.92 ± 0.27 mg·kg(-1)·min(-1) per μU/ml) were observed in the AE group but not the RE group. Improvements in insulin sensitivity in the AE group were associated with the reductions in total AT mass (r = -0.65, P = 0.02). In obese adolescent girls, AE but not RE is effective in reducing liver fat and visceral adiposity and improving insulin sensitivity independent of weight loss or calorie restriction.

The effect of a single 2 h bout of aerobic exercise on ectopic lipids in skeletal muscle, liver and the myocardium.

AIMS/HYPOTHESIS Ectopic lipids are fuel stores in non-adipose tissues (skeletal muscle [intramyocellular lipids; IMCL], liver [intrahepatocellular lipids; IHCL] and heart [intracardiomyocellular lipids; ICCL]). IMCL can be depleted by physical activity. Preliminary data suggest that aerobic exercise increases IHCL. Data on exercise-induced changes on ICCL is scarce. Increased IMCL and IHCL have been related to insulin resistance in skeletal muscles and liver, whereas this has not been documented in the heart. The aim of this study was to assess the acute effect of aerobic exercise on the flexibility of IMCL, IHCL and ICCL in insulin-sensitive participants in relation to fat availability, insulin sensitivity and exercise capacity. METHODS Healthy physically active men were included. [Formula: see text] was assessed by spiroergometry and insulin sensitivity was calculated using the HOMA index. Visceral and subcutaneous fat were separately quantified by MRI. Following a standardised dietary fat load over 3 days, IMCL, IHCL and ICCL were measured using MR spectroscopy before and after a 2 h exercise session at 50-60% of [Formula: see text]. Metabolites were measured during exercise. RESULTS Ten men (age 28.9 ± 6.4 years, mean ± SD; [Formula: see text] 56.3 ± 6.4 ml kg(-1) min(-1); BMI 22.75 ± 1.4 kg/m(2)) were recruited. A 2 h exercise session resulted in a significant decrease in IMCL (-17 ± 22%, p = 0.008) and ICCL (-17 ± 14%, p = 0.002) and increase in IHCL (42 ± 29%, p = 0.004). No significant correlations were found between the relative changes in ectopic lipids, fat availability, insulin sensitivity, exercise capacity or changes of metabolites during exercise. CONCLUSIONS/INTERPRETATION In this group, physical exercise decreased ICCL and IMCL but increased IHCL. Fat availability, insulin sensitivity, exercise capacity and metabolites during exercise are not the only factors affecting ectopic lipids during exercise.

Effects of aerobic exercise on ectopic lipids in patients with growth hormone deficiency before and after growth hormone replacement therapy

Growth hormone replacement therapy (GHRT) increases exercise capacity and insulin resistance while it decreases fat mass in growth hormone-deficient patients (GHD). Ectopic lipids (intramyocellular (IMCL) and intrahepatocellular lipids (IHCL) are related to insulin resistance. The effect of GHRT on ectopic lipids is unknown. It is hypothesized that exercise-induced utilization of ectopic lipids is significantly decreased in GHD patients and normalized by GHRT. GHD (4 females, 6 males) and age/gender/waist-matched control subjects (CS) were studied. VO2max was assessed on a treadmill and insulin sensitivity determined by a two-step hyperinsulinaemic-euglycaemic clamp. Visceral (VAT) and subcutaneous (SAT) fat were quantified by MR-imaging. IHCL and IMCL were measured before and after a 2 h exercise at 50-60% of VO2max using MR-spectroscopy (∆IMCL, ∆IHCL). Identical investigations were performed after 6 months of GHRT. VO2max was similar in GHD and CS and significantly increased after GHRT; GHRT significantly decreased SAT and VAT. 2 h-exercise resulted in a decrease in IMCL (significant in CS and GHRT) and a significant increase in IHCL in CS and GHD pre and post GHRT. GHRT didn't significantly impact on ∆IMCL and ∆IHCL. We conclude that aerobic exercise affects ectopic lipids in patients and controls. GHRT increases exercise capacity without influencing ectopic lipids.

Cognitively engaging chronic physical activity, but not aerobic exercise, affects executive functions in primary school children: A group-randomized controlled trial

Although the positive effects of different kinds of physical activity (PA) on cognitive functioning have already been demonstrated in a variety of studies, the role of cognitive engagement in promoting children’s executive functions is still unclear. The aim of the present study was therefore to investigate the effects of two qualitatively different chronic PA interventions on executive functions in primary school children. 181 children aged between 10 and 12 years were assigned to either a 6-week physical education program with a high level of physical exertion and high cognitive engagement (team games), a physical education program with high physical exertion but low cognitive engagement (aerobic exercise), or to a physical education program with both low physical exertion and low cognitive engagement (control condition). Executive functions (updating, inhibition, shifting) and aerobic fitness (multistage 20-meter shuttle run test) were measured before and after the respective condition. Results revealed that both interventions (team games and aerobic exercise) have a positive impact on children’s aerobic fitness (4-5 % increase in estimated VO2max). Importantly, an improvement in shifting performance was found only in the team games and not in the aerobic exercise or control condition. Thus, the inclusion of cognitive engagement in PA seems to be the most promising type of chronic intervention to enhance executive functions in children, providing further evidence for the importance of the qualitative aspects of PA.

The heart challenge: The effect of regular aerobic exercise on body fat distribution in third and fourth grade school children: A randomized clinical trial

The pattern of body fat distribution known as "centralized", and characterized by a predominance of subcutaneous fat on the trunk and a "pot belly", has been associated with an increased risk of chronic disease. These patterns of fat distribution, as well as the lifestyle habit variables associated with adult fatness and chronic morbidity clearly begin to develop during childhood, indicating the need for intervention and primary prevention of obesity, particularly the centralized form, during childhood or adolescence. The purpose of this study was to determine whether regular aerobic exercise could beneficially alter the distribution of body fat in 8 and 9 year old children. One hundred and eighty-eight participants were randomized into either a regular aerobic exercise treatment group or a standard physical education program control group. A variety of aerobic activities was used for intervention 5 days per week during physical education class for a period of 12 weeks. Fat distribution was measured by a number of the most commonly used indices, including ratios of body circumferences and skinfolds and indices derived from a principal components analysis. Change over time in average pulse rate was used to determine if intervention actually occurred. Approximately 10% of the students were remeasured, allowing the calculation of intra- and interexaminer measurement reliability estimates for all indices.^ This study group was comparable to the U.S. population, though the study children were slightly larger for certain measures. No effect of the exercise intervention was found. The most likely explanation for this was inadequacy of the intervention, as indicated by the lack of any change in average pulse rate with treatment. The results of the measurement reliability analysis are reported and indicate that body circumference ratios are more precise than skinfold ratios, particularly when multiple observers are used. Reliability estimates for the principal component indices were also high.^ It remains unclear whether the distribution of body fat can be altered with exercise. It is likely that this issue will remain undecided until one highly reliable, valid, and sensitive measure of fat distribution can be found. ^

Carotid body chemoreceptor regulation of blood glucose during aerobic exercise

Regulación carótida en ejercicio aeróbico

Influencia de un programa de ejercicio aeróbico en la calidad de vida de pacientes afectadas por cáncer de mama = Influence of an aerobic exercise program on breast cancer patients’ quality of life

INTRODUCCIÓN Actualmente las supervivientes de cáncer de mama viven durante más tiempo. Sin embargo, los tratamientos utilizados presentan importantes efectos secundarios que afectan y marcan su calidad de vida. Numerosos estudios han mostrado que el ejercicio es una herramienta apta, segura y efectiva reduciendo algunos de estos efectos secundarios y, en suma, mejorando la calidad de vida de estas pacientes, aspecto que presenta al ejercicio físico como una intervención integral para ellas. Por el contrario, se ha observado que las supervivientes de cáncer de mama reducen la cantidad de ejercicio que realizan después de dichos tratamientos. Por ello, el objetivo de este proyecto es examinar los efectos de un programa integral de ejercicio en la calidad de vida y la cantidad de ejercicio físico que realizan las pacientes con cáncer de mama en su tiempo, tras finalizar sus tratamientos. MATERIAL Y MÉTODOS Se diseñó un Ensayo Clínico Aleatorizado. Noventa pacientes diagnosticadas de cáncer de mama en estadios tempranos que habían terminado sus tratamientos de radioterapia y quimioterapia recientemente, fueron reclutadas por la Universidad Politécnica de Madrid, desde enero de 2013 hasta junio de 2014. Las pacientes fueron aleatorizadas tras las mediciones iniciales al grupo control (tratamientos habituales) o grupo intervención, durante tres meses. La intervención consistió en 24 clases de ejercicio combinando práctica aeróbica y de fuerza con el fin de reducir los efectos secundarios de dichos tratamientos. La calidad de vida, la cantidad de ejercicio físico realizado en tiempo de ocio, VO2max, la fuerza, la movilidad articular del hombro, la fatiga, la depresión y la ansiedad fueron medidos al inicio y después de los tres meses en todos los pacientes. RESULTADOS Un total de 89 pacientes con una media de 49.06±8.75 de edad fueron finalmente analizadas. El grupo intervención (n=44) mostraron significativamente mejores resultados en calidad de vida (p=0.0001; d=0.85), cantidad de ejercicio en tiempo de ocio (p=0.0001; d=2.77), en variables de la composición corporal, en variables físicas y en variables psicológicas comparado con el grupo control (n=45). Además, se observó una correlación significativa entre la calidad de vida y el ejercicio realizado en tiempo de ocio en el grupo intervención (r= 0.58; p=0.001), que no fue patente en el grupo control. Se observaron cambios significativos en el grupo de intervención relativos a la composición corporal, con aumento de la masa muscular (p=0.001) y reducción de la masa grasa (p=0.0001). Tanto las variables físicas como psicológicas también mostraron diferencias significativas a favor al grupo de intervención en las comparaciones entre grupos. CONCLUSIONES Según estos resultados, un programa de ejercicio físico específico es una intervención integral que mejora los hábitos y la calidad de vida de las supervivientes de cáncer de mama, lo que reduce determinados efectos secundarios de los tratamientos y aumenta la salud física y psicológica general de estas mujeres. Este tipo de intervenciones pude ser una herramienta barata y efectiva para ofrecer a los pacientes, integrada en los tratamientos habituales. ABSTRACT INTRODUCTION It is well known that breast cancer survivors are living longer. However, breast cancer treatments present serious side effects, which could affect breast cancer survivors’ (BCS) health and quality of life (QoL). Exercise has been presented as a feasible, safe and effective tool in reducing some of these side effects and to improve survivors’ QoL, acting as an integrative treatment for them, although it has been observed that BCS reduce their leisure time exercise (LTE) levels. Therefore, the aim of this study was to examine the effects of an integrative exercise program in QoL and LTE in BCS after the completion of their adjuvant treatment. MATERIAL AND METHODS A randomized controlled trial (RCT) was designed. Ninety patients diagnosed with an early stage of breast cancer and who recently finished chemotherapy and radiotherapy treatments were recruited by the Technical University of Madrid from January 2013 to June 2014. Patients were randomized after baseline assessments to the intervention group (IG) or to the control group (CG) (usual care) for three months. The Intervention consisted in 24 supervised exercise classes, combining aerobic and resistance exercises in order to reduce the most common side effects of the treatments. QoL, LTE, body composition, VO2max, strength, shoulder range of motion, fatigue, depression and self-esteem were measured in all the patients at baseline and after three months. RESULTS A total of 89 patients aged 49.06±8.75 years were finally assessed. IG (n=44) showed significant better results in QoL (p=0.0001; d=0.85), LTE (p=0.0001; d=2.77), in body composition, in the physical variable and in psychological outcomes, compared with the CG (n=45). In addition, a correlation between QoL and LTE (r= 0.58; p=0.001) was found in the IG, while CG did not show this correlation. Significant changes in body composition were observed in the group comparisons, especially in lean mass (p=0.001) and body fat mass (p= 0.0001). Positive changes were also observed in the physical and psychological variables in comparisons between groups. CONCLUSIONS These results suggest that this exercise program may be an integrative intervention, which is able to improve QoL and LTE levels in breast cancer survivors, reducing breast cancer side effects of treatments and improving their physical and psychological general health. Exercise may be an effective and inexpensive strategy to be included in patients integrative care.