Changes In Maximal Oxygen Consumption Research Articles

High-Intensity Interval vs. Moderate-Intensity Continuous Training in Parkinson's Disease: A Randomized Trial.

Exercise training is recommended to improve quality of life in those living with Parkinson's Disease (PD); however, the optimal prescription to improve cardiorespiratory fitness and disease-related motor symptoms remains unknown. Twenty-nine participants with PD were randomly allocated to either 10-weeks of high-intensity interval training (HIIT) (n=15; 6 female) or moderate-intensity continuous training (MICT) (n=14; 5 female). The primary outcome was the change in maximal oxygen consumption (VO2peak). Secondary outcomes included changes in the Unified Parkinson's Disease Rating Scale (UPDRS) Part III motor score, Parkinson's Disease Fatigue Scale (PFS-16), resting and exercise cardiovascular measures, gait, balance, and knee extensor strength and fatigability. Exercise training increased VO2peak (main effect of time, P<0.01), with a clinically-meaningful difference in the change following HIIT vs. MICT (∆3.7±3.7 vs. 1.7±3.2 ml∙kg-1∙min-1, P=0.099). The UPDRS motor score improved over time (P<0.001) but without any differences between HIIT vs. MICT (∆-9.7±1.3 vs. -8.4±1.4, P=0.51). Self-reported subjective fatigue (PFS-16) decreased over time (P<0.01) but was similar between HIIT and MICT groups (P=0.6). Gait, balance, blood pressure, and heart rate were unchanged with training (all P>0.09). Knee extensor strength increased over time (P=0.03) but did not differ between HIIT vs. MICT (∆8.2±5.9 vs. 11.7±6.2 Nm, P=0.69). HIIT alone increased muscular endurance of the knee extensors during an isotonic task to failure (P=0.04). In participants with PD, HIIT and MICT both increased VO2peak and led to improvements in motor symptoms and perceived fatigue; HIIT may offer the potential for larger changes in VO2peak and reduced knee extensor fatigability.

Efficacy of Lactococcus lactis subsp. lactis LY-66 and Lactobacillus plantarum PL-02 in Enhancing Explosive Strength and Endurance: A Randomized, Double-Blinded Clinical Trial.

Probiotics are posited to enhance exercise performance by influencing muscle protein synthesis, augmenting glycogen storage, and reducing inflammation. This double-blind study randomized 88 participants to receive a six-week intervention with either a placebo, Lactococcus lactis subsp. lactis LY-66, Lactobacillus plantarum PL-02, or a combination of both strains, combined with a structured exercise training program. We assessed changes in maximal oxygen consumption (VO2max), exercise performance, and gut microbiota composition before and after the intervention. Further analyses were conducted to evaluate the impact of probiotics on exercise-induced muscle damage (EIMD), muscle integrity, and inflammatory markers in the blood, 24 and 48 h post-intervention. The results demonstrated that all probiotic groups exhibited significant enhancements in exercise performance and attenuation of muscle strength decline post-exercise exhaustion (p < 0.05). Notably, PL-02 intake significantly increased muscle mass, whereas LY-66 and the combination therapy significantly reduced body fat percentage (p < 0.05). Analysis of intestinal microbiota revealed an increase in beneficial bacteria, especially a significant rise in Akkermansia muciniphila following supplementation with PL-02 and LY-66 (p < 0.05). Overall, the combination of exercise training and supplementation with PL-02, LY-66, and their combination improved muscle strength, explosiveness, and endurance performance, and had beneficial effects on body composition and gastrointestinal health, as evidenced by data obtained from non-athlete participants.

The Influence of Different SARS-CoV-2 Strains on Changes in Maximal Oxygen Consumption, Ventilatory Efficiency and Oxygen Pulse of Elite Athletes.

The aim of this study was to evaluate the influence of different SARS-CoV-2 strains on the functional capacity of athletes. In total, 220 athletes underwent cardiopulmonary exercise testing (CPET) after coronavirus infection and before returning to sports activities. Eighty-eight athletes were infected by the Wuhan virus, and 66 were infected during the Delta and Omicron strain periods of the pandemic. The CPET results showed significantly decreased maximal oxygen consumption, ventilatory efficiency, and oxygen pulse in athletes who were infected with Wuhan and Delta strains compared to athletes who suffered from Omicron virus infection. An early transition from aerobic to anaerobic metabolic pathways for energy production was observed in the Wuhan and Delta groups but not in athletes who were infected with the Omicron strain. There were no differences in the obtained results when Wuhan and Delta virus variants were compared. These results suggest that the Wuhan and Delta virus strains had a significantly greater negative impact on the functional abilities of athletes compared to the Omicron virus variant, especially in terms of aerobic capacity and cardiorespiratory function.

Effects of the addition of high- vs. low-intensity resistance training on top of endurance training in patients with heart failure: preliminary results from a randomized clinical trial

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): Hasselt University Background Adding resistance training on top of endurance training is recommended in the rehabilitation of patients with heart failure. However, it is unknown which intensity of resistance training should be preferred. Purpose To compare the effects of the addition of high- vs. low-intensity resistance training on top of endurance training in patients with heart failure. Methods Nineteen patients with heart failure were block randomized (by gender and sex) in a combined high-intensity resistance and endurance group (HIG; n=8, age=61±12y, 7 males, LVEF=38±10%) vs. combined low-intensity resistance and endurance group (LIG; n=9, age=68±21y, 8 males, LVEF=38±13%). Patients trained 3x/week for 45 sessions. The resistance exercises were volume-matched between groups and consisted of three sets of leg press, pull down and dip exercises, separated by 30s of rest, done at 55-70% 1RM in HIG vs. 35-40% 1RM in LIG. Both groups did moderate-intense endurance training on a bicycle, cross-trainer, treadmill and arm ergometer for 30 min per training. Maximal oxygen consumption was evaluated with an incremental cardiopulmonary cycling test and muscle strength by 1-RM testing, while quality of life was assessed with the Minnesota questionnaire, and walking distance by a 6-minute walking test. Mann-Whitney U test was used for analyzing differences between groups in all variables and Wilcoxon signed-rank test for evaluating pre-post difference of the entire sample. P values &amp;lt;0,05 (2-tailed) were considered statistically significant. Results Training adherence was similar in both groups (LIG vs HIG: 41±6 vs 37±9 sessions, p=0,370; Table 1). Overall, the intervention improved maximal oxygen consumption, walking capacity and muscle strength (p&amp;lt;0,05), but the between-group changes in maximal oxygen consumption (LIG vs HIG: 3±2 vs 3±4 ml/kg/min, p=0,963), quality of life (LIG vs HIG: -8±23 vs -1±5 points, p=0,931) and muscle strength (LIG vs HIG: Dip 34±34 vs 18±20kg, p=0,481; Leg press, 66±87 vs 47±53kg, p=0,486; Pull down, 9±6 vs 9±7kg, p=0,574) were similar. Conclusion Adding either high- or low-intensity resistance training on top of endurance training seems equally effective for improving aerobic capacity and walking performance in patients with heart failure. The study is ongoing.

Functional improvement following direct interventional leaflet repair of severe tricuspid regurgitation.

AimsSeveral new percutaneous tricuspid repair systems have recently been introduced as new treatment options for severe tricuspid regurgitation (TR). Clinical improvement following percutaneous tricuspid valve leaflet repair has been demonstrated by recent studies. A possible impact on exercise capacity has not yet been reported.Methods and resultsEleven patients with at least severe TR and successful tricuspid leaflet repair using the PASCAL Ace implant at our cardiology department were included in this analysis. All patients suffered from symptomatic right‐sided heart failure with compromised exercise capacity. Cardiopulmonary exercise testing (CPET), clinical, laboratory, and echocardiographic parameters were assessed at baseline and 3 months follow‐up. The primary endpoint was the change in maximal oxygen consumption [VO2 max (mL/(min*kg))] at 3 months follow‐up. Secondary endpoints included improvement in TR, cardiac biomarkers, and other clinical outcomes. TR severity at 3 months follow‐up post‐PASCAL Ace implantation was significantly lower than at baseline (P = 0.004). Cardiac biomarkers including high‐sensitivity troponin T and N‐terminal pro‐brain natriuretic peptide as well as right ventricular diameter improved slightly without reaching statistical significance (P = 0.89, P = 0.32, and P = 0.06, respectively). PASCAL Ace implantation resulted in a significant improvement in cardiopulmonary exercise capacity at 3 months follow‐up compared with baseline. Mean VO2 max improved from 9.5 ± 2.8 to 11.4 ± 3.4 mL/(min*kg) (P = 0.006), VO2 max per cent predicted from 42 ± 12% to 50 ± 15% (P = 0.004), peak oxygen uptake from 703 ± 175 to 826 ± 198 mL/min (P = 0.004), and O2 pulse per cent predicted from 67 ± 21% to 81 ± 25% (P = 0.011). Other CPET‐related outcomes did not show any significant change over time.ConclusionsIn this single‐centre retrospective analysis, direct tricuspid valve leaflet repair using the transcatheter PASCAL Ace implant system was associated with a reduced TR severity and improved cardiopulmonary exercise capacity.

Sports Medicine International Open - recently published.

This study sought to examine time course changes in maximal oxygen consumption (VO2max) confirmed with verification testing following 12 weeks of standardized vs. individualized exercise training. Participants (N=39) were randomly allocated to differing exercise intensity prescription groups: ventilatory threshold (individualized) or % heart rate reserve (standardized).

Time Course Changes in Confirmed 'True' VO 2 max After Individualized and Standardized Training.

This study sought to examine time course changes in maximal oxygen consumption (VO 2 max) confirmed with verification testing following 12 weeks of standardized vs. individualized exercise training. Participants (N=39) were randomly allocated to differing exercise intensity prescription groups: ventilatory threshold (individualized) or % heart rate reserve (standardized). At baseline, 4, 8, and 12 weeks, participants completed maximal exercise testing with a verification protocol to confirm ‘true VO 2 max.’ VO 2 max in the standardized group changed from 24.3±4.6 ml·kg −1 ·min −1 at baseline to 24.7±4.6, 25.9±4.7, and 26.0±4.2 ml·kg −1 ·min −1 at week 4, 8, and 12, respectively, with a significant difference (p<0.05) in VO 2 max at week 8 and 12 compared to baseline. The individualized group had increases in VO 2 max from online 2 9.5±7.5 ml·kg −1 ·min −1 at baseline to 30.6±8.4, 31.4±8.4, and 32.8±8.6 ml·kg −1 ·min −1 at week 4, 8, and 12, respectively. In the individualized group, there were significant differences (p<0.05) in VO 2 max from baseline to week 8 and 12 and a significant increase in VO 2 max from week 8 to 1 online 2 . Although not statistically significant, our preliminary data demonstrates a more rapid and potent improvement in VO 2 max when exercise intensity is individualized. This is the first investigation to employ use of the verification procedure to confirm ‘true VO 2 max’ changes following exercise training using ventilatory thresholds.

Short-term heat acclimation improves the determinants of endurance performance and 5-km running performance in the heat.

This study investigated the effect of 5 days of controlled short-term heat acclimation (STHA) on the determinants of endurance performance and 5-km performance in runners, relative to the impairment afforded by moderate heat stress. A control group (CON), matched for total work and power output (2.7 W·kg-1), differentiated thermal and exercise contributions of STHA on exercise performance. Seventeen participants (10 STHA, 7 CON) completed graded exercise tests (GXTs) in cool (13 °C, 50% relative humidity (RH), pre-training) and hot conditions (32 °C, 60% RH, pre- and post-training), as well as 5-km time trials (TTs) in the heat, pre- and post-training. STHA reduced resting (p = 0.01) and exercising (p = 0.04) core temperature alongside a smaller change in thermal sensation (p = 0.04). Both groups improved the lactate threshold (LT, p = 0.021), lactate turnpoint (LTP, p = 0.005) and velocity at maximal oxygen consumption (vV̇O2max; p = 0.031) similarly. Statistical differences between training methods were observed in TT performance (STHA, -6.2(5.5)%; CON, -0.6(1.7)%, p = 0.029) and total running time during the GXT (STHA, +20.8(12.7)%; CON, +9.8(1.2)%, p = 0.006). There were large mean differences in change in maximal oxygen consumption between STHA +4.0(2.2) mL·kg-1·min-1 (7.3(4.0)%) and CON +1.9(3.7) mL·kg-1·min-1 (3.8(7.2)%). Running economy (RE) deteriorated following both training programmes (p = 0.008). Similarly, RE was impaired in the cool GXT, relative to the hot GXT (p = 0.004). STHA improved endurance running performance in comparison with work-matched normothermic training, despite equality of adaptation for typical determinants of performance (LT, LTP, vV̇O2max). Accordingly, these data highlight the ergogenic effect of STHA, potentially via greater improvements in maximal oxygen consumption and specific thermoregulatory and associated thermal perception adaptations absent in normothermic training.

Tracking changes in maximal oxygen consumption with the heart rate index in female collegiate soccer players.

The purpose of this study was to determine if the HRindex Method (VO2max = [6 x HRindex – 5] x 3.5, where HRindex = HRmax/HRrest) was accurate for tracking changes in VO2max following 8-weeks of endurance training among collegiate female soccer players. Predicted VO2max via the HRindex Method and observed VO2max from a maximal exercise test on a treadmill were determined for a group of female soccer athletes (n = 15) before and following an 8-week endurance training protocol. The predicted (pVO2max) and observed (aVO2max) values were compared at baseline and within 1-week post-training. Change values (i.e., the difference between pre to post) for each variable were also determined and compared. There was a significant difference between aVO2max before (43.2 ± 2.8 ml·kg·min−1) and following (46.2 ± 2.1 ml·kg·min−1) the 8-week training program (p < 0.05). However, pVO2max did not significantly change following training (pre = 43.4 ± 4.6 ml·kg·min−1, post = 42.9 ± 4.1 ml·kg·min−1, p = 0.53). Furthermore, the correlation between the change in aVO2max and the change in pVO2max was trivial and non-significant (r = 0.30, p = 0.28). The HRindex Method does not appear to be suitable for predicting changes in VO2max following 8-weeks of endurance training in female collegiate soccer players.

Special Considerations for Exercise Testing and Programming for Individuals With Spinal Cord Injury

Special Considerations for Exercise Testing and Programming for Individuals With Spinal Cord Injury

Monitoring changes in VO2max via the Polar FT40 in female collegiate soccer players

This study was conducted to determine if the Polar FT40 could accurately track changes in maximal oxygen consumption (VO2max) in a group of female soccer players. Predicted VO2max (pVO2max) via the Polar FT40 and observed VO2max (aVO2max) from a maximal exercise test on a treadmill were determined for members of a collegiate soccer team (n = 20) before and following an 8-week endurance training protocol. Predicted (VO2max and aVO2max measures were compared at baseline and within 1 week post-training. Change values (i.e., the difference between pre to post) for each variable were also determined and compared. There was a significant difference in aVO2max (pre = 43.6 ± 2.4 ml · kg · min−1, post = 46.2 ± 2.4 ml · kg · min−1, P < 0.001) and pVO2max (pre = 47.3 ± 5.3 ml · kg · min−1, post = 49.7 ± 6.2 ml · kg · min−1, P = 0.009) following training. However, predicted values were significantly greater at each time point compared to observed values (P < 0.001 at pre and P = 0.008 at post). Furthermore, there was a weak correlation between the change in aVO2max and the change in pVO2max (r = 0.18, P = 0.45). The Polar FT40 does not appear to be a valid method for predicting changes in individual VO2max following 8 weeks of endurance training in female collegiate soccer players.

The effect of Bosentan on exercise capacity in Fontan patients; rationale and design for the TEMPO study

BackgroundPalliative treatment with the Fontan procedure has greatly improved survival for children with functionally univentricular heart. Since Fontan performed the first successful operation, the procedure has evolved and is now performed as Total Cavo-Pulmonary Connection (TCPC).An increasing prevalence and longer life expectancy of TCPC patients have raised new challenges. The survivors are often suffering complications such as arrhythmias, myocardial dysfunction, thromboembolic events, neuropsychological deficit, protein-losing enteropathy and reduced exercise capacity. Several causes for the reduced exercise capacity may be present e.g. impaired function of the single ventricle, valve dysfunction and chronotropic impairment, and perhaps also increased pulmonary vascular resistance. Thus, plasma endothelin-1 has been shown to correlate with increased pulmonary vascular resistance and the risk of failing Fontan circulation. This has raised the question of the role for pulmonary vasodilation therapy, especially endothelin receptor antagonist in the management of TCPC patients.Methods/DesignThe TEMPO trial aims to investigate whether Bosentan, an endothelin receptor antagonist, can be administered safely and improve exercise capacity in TCPC patients. The trial design is randomized, double-blind and placebo-controlled. Bosentan/placebo is administered for 14 weeks with control visits every four weeks. The primary endpoint is change in maximal oxygen consumption as assessed on bicycle ergometer test. Secondary endpoints include changes in pulmonary blood flow during exercise test, pro brain natriuretic peptide and quality of life.DiscussionWe hypothesize that treatment with Bosentan, an endothelin receptor antagonist, can be administered safely and improve exercise capacity in TCPC patients.Trial registrationclinicaltrials.gov NCT01292551

Change in Insulin Sensitivity with Weight Gain is Determined by Fatness Better than by Fitness

Insulin sensitivity is known to be reduced in obese individuals, but it is not clear whether this is related more to the accretion of fat or to inactivity. PURPOSE: To examine the contributions of fitness versus fat measures to changes in insulin sensitivity (SI) over two years in 130 obesity-prone premenopausal women (65 African American and 65 Caucasian) who had recently lost weight through diet and exercise. We tested the hypothesis that changes in SI would be best predicted by changes in intra-abdominal and deep subcutaneous abdominal fat depots and would be less predicted by changes in maximal oxygen consumption (VO2max). METHODS: We used the VO2max, intra-abdominal adipose tissue (IAAT), superficial subcutaneous abdominal adipose tissue (SSAT), deep subcutaneous abdominal adipose tissue (DSAT), total percent fat, total fat mass, leg fat, and lean mass as possible predictors of SI calculated from the minimal model method and compared these predictors using AIC scores across and within self-reported race. RESULTS: In two years of follow-up, average BMI increased from 23.9 to 27.1 and the subjects gained an average of 8.2kg and 6.3% body fat. During this time, maximal oxygen consumption decreased from 33.2 to 30.1 ml/kg.min and SI decreased from 4.45 to 3.77 [× 10-4 min-1/(μIU/ml)]. In our cohort, the change in SI was best predicted by changes in SSAT, IAAT, and total fat mass and was least related to changes in lean mass and VO2max. When we grouped our subjects by race, we found that SI is best predicted by IAAT in Caucasian women and by SSAT in African American women. VO2max was not among the best predictors of SI in either group. CONCLUSION: Our results support our hypothesis that the reduction in insulin sensitivity is predicted better by measures of obesity, specifically central obesity, than by fitness.

Pericardial Fat Loss in Postmenopausal Women under Conditions of Equal Energy Deficit

Weight loss induced by caloric restriction (CR) or aerobic exercise can reduce pericardial fat, and these reductions may help improve cardiovascular health. We examined whether combining CR with aerobic exercise enhances pericardial fat loss compared with a CR-only intervention designed to elicit equivalent reductions in body weight. We also examined the relationship between changes in pericardial fat and changes in maximal oxygen consumption (V˙O2max), a measure of cardiorespiratory fitness. Thirty-two abdominally obese postmenopausal women (mean age=58 yr; 78% Caucasian) were randomly assigned to one of three interventions of equal energy deficit (∼2800 kcal·wk) for 20 wk: CR only (n=8), CR + moderate-intensity exercise (n=15), or CR + vigorous-intensity exercise (n=9). The volume of pericardial fat around the coronary arteries was measured by computed tomography. Women in the CR, CR + moderate-intensity, and CR + vigorous-intensity groups had similar baseline characteristics. The mean ± SD value for pericardial fat before weight loss was 79.07 ± 32.90 cm (range=34.04-152.74 cm), with no difference among groups (P=0.89). All three interventions significantly reduced body weight (15%), waist circumference (10%), and abdominal visceral fat (28%) to a similar degree. There was also a 17% reduction in pericardial fat (-12.75 ± 6.29 cm, P<0.0001), which did not differ among groups (P=0.84). Changes in pericardial fat were inversely correlated with changes in V˙O2max (r=-0.37, P=0.05), but not after adjusting for intervention group and change in body weight. Weight loss interventions of equal energy deficit have similar effects on pericardial fat in postmenopausal women, regardless of whether the energy deficit is due to CR alone or CR plus aerobic exercise.

Metabolic Conditioning Among Soccer Players

To reduce the risk of overuse injuries, yet obtain optimal fitness development among soccer players, research comparing different training strategies is required. This study compared conventional group conditioning (GRP) to individualized training (IT) during the preseason among female college soccer players. Both groups participated in soccer practices; however, players were randomly assigned to supplemental conditioning differentiated by the use of player-specific heart rate training in the IT group. Changes in maximal oxygen consumption, anaerobic threshold, and rate of recovery were analyzed before and after 12 weeks of conditioning. Data analysis identified significantly (p < 0.05) greater improvements in the IT group in all 3 variables, despite considerably less training volume. Based on these data, it is apparent that catering training to the fitness level of each individual player can have a positive impact on training adaptations.

Rate and mechanism of maximal oxygen consumption decline with aging: implications for exercise training.

Because of the influence of cardiorespiratory fitness on functional independence, quality of life, and cardiovascular disease and all-cause mortality, tremendous interest has been directed towards describing the age-related change in maximal oxygen consumption (VO(2max)). Current evidence supports a 10% per decade decline in VO(2max) in men and women regardless of activity level. High-intensity exercise may reduce this loss by up to 50% in young and middle-aged men, but not older men, if maintained long term. Middle-aged and older women do not appear to be able to reduce loss rates in VO(2max) to less than 10% per decade, which may be related to estrogen status. However, maintaining high-intensity training seems limited to approximately one decade at best and to a select few individuals. While the factors limiting the ability to maintain high-intensity training are not completely known, aging most likely plays a role as studies have demonstrated that training maintenance becomes more difficult with advancing age. Age-related loss of VO(2max) seems to occur in a non-linear fashion in association with declines in physical activity. In sedentary individuals, this non-linear decline generally occurs during the twenties and thirties whereas athletic individuals demonstrate a non-linear decline upon decreasing or ceasing training. Non-linear loss rates are also demonstrated in individuals over the age of 70 years. The decline in VO(2max) seems to be due to both central and peripheral adaptations, primarily reductions in maximal heart rate (HR(max)) and lean body mass (LBM). Exercise training does not influence declines in HR(max), while LBM can be maintained to some degree by exercise. Recommendations for exercise training should include aerobic activities utilising guidelines established by the American College of Sports Medicine for improving CV fitness and health, as well as strength training activities for enhancing LBM.

ASSESSING CHANGE IN VO2MAX WITH A NON-EXERCISE REGRESSION MODEL

PURPOSE: This study evaluated the ability of a non-exercise regression model (NERM) to predict changes in maximal oxygen consumption (δVO2 MAX) using the baseline (T0) and 6 month (T6) post-intervention data collected for the Activity Counseling Trial (ACT) (Simons-Morton et al. Prev Med 31:513-521, 2000). METHODS: Complete records at both T0 and T6 for 272 women and 374 men between 35 and 75 yrs of age were used to generate a VO2 MAX prediction equation using non-exercise based independent variables (gender, body weight, height, self-reported mins of daily walking) using standard multiple regression, cross-validation, and PRESS analytical procedures. The final NERM was then used to predict VO2 MAX in the same subjects at T6 where actual δVO2 MAX between T6 and T0 was compared to predicted δVO2 MAX (difference between predicted T6 and T0 values) across four δVO2 MAX categories (< -5, ≥ -5 & < 0, ≥ 0 & < 5, & > 5 ml/kg/min) using a 2-factor RM ANOVA. RESULTS: Mean predicted VO2 MAX did not differ from measured VO2 MAX across gender or age quintile subsamples, but δVO2 MAX was statistically under predicted within all δVO2 MAX categories. These results are due to actual change in only one of the predictor variables (mins of daily walking) between T0 (101 ± 86 mins) and T6 (124 ± 100 mins) which also had the lowest standardized coefficient. CONCLUSIONS: The NERM was reasonably effective at predicting mean VO2 MAX values within subsamples following a 6 month intervention, but mean changes in measured VO2 MAX were systematically under predicted. Future NERM's may be more capable of predicting change in VO2 MAX with better independent variables for tracking change in physical activity behavior. Project ACT supported by NHLBI contracts: N01-HC-45135, N01-HC-45136, N01-HC-45137, N01-HC-45138

Skeletal muscle strength and endurance in patients with mild COPD and the effects of weight training

This study poses two questions: 1) is there an abnormality in isokinetic skeletal muscle strength and endurance in mild chronic obstructive pulmonary disease (COPD)? and 2) what is the effect of a randomized, controlled, 12 week hospital outpatient weight training programme in terms of skeletal muscle function and exercise tolerance? Upper and lower limb isokinetic maximum and sustained muscle function were compared in 43 COPD patients (age 49+/-11 yrs), mean forced expiratory volume in one second (FEV1) 77+/-23% pred and 52 healthy, sedentary subjects (age 51 (10) yrs), mean FEV1 109+/-16% pred. The 43 COPD patients were randomly allocated into training (n=26) and control (n=17) groups. Isokinetic and isotonic muscle function, whole body endurance, maximal exercise capacity and lung function were measured. The COPD patients had reduced isokinetic muscle function (with the exception of sustained upper limb strength) as compared with healthy sedentary subjects. Muscle function improved after weight training in the COPD patients. Whole body endurance during treadmill walking also improved with no change in maximal oxygen consumption. A deficit in skeletal muscle function can be identified in patients with mild chronic obstructive pulmonary disease which cannot be explained by factors such as hypoxaemia and malnutrition. Intervention with weight training is effective in countering this deficit which the authors conclude is probably due to muscle deconditioning.

Changes in plasma leptin and insulin action with resistive training in postmenopausal women.

To determine the effects of 16 weeks of resistive training alone (RT) and with weight loss (RT+WL) on insulin action, plasma leptin concentrations and leptin's relationship to beta-cell sensitivity to glucose, resting metabolic rate (RMR), and plasma catecholamines in older women. Fifteen obese postmenopausal women aged 50-69 y. Body composition (by dual-energy X-ray absorptiometry), RMR (by indirect calorimetry), insulin action (by 2 h hyperglycemic clamps; 7.9 mmol/l above basal plasma glucose levels), plasma leptin and insulin (by RIA), and plasma catecholamines (by enzymatic methods). RT and RT+WL resulted in significant improvements in muscular strength (P<0.01) with no changes in maximal oxygen consumption. Body weight, fat mass and percent body fat did not change with RT, but decreased with RT+WL (P<0.001). Fat-free mass and RMR increased after training when both groups were combined (P<0.05). The insulin response during the last 20 min of the 2 h hyperglycemic clamps decreased 16% after RT (P=0.05), 43% after RT+WL (P<0.05), and 29% in the entire group (P<0. 01) without any changes in glucose utilization. Plasma leptin levels did not change after RT, but decreased by 36% after RT+WL (P<0.05). Baseline leptin levels correlated with body weight (r=0.68, P<0.01), body fat mass (r=0.77, P<0.001), and RMR (kcal/d; (r=0.69, P<0.005), but not with baseline norepinephrine or epinephrine levels. Plasma leptin levels correlated with basal insulin (r=0.73, P<0.005), and approached significance with the 0-10 min and 100-120 min insulin response to hyperglycemia before training (both r=0.51, P=0.07). In the entire group, the change in insulin response from 100-120 min during the clamp correlated with the change in leptin levels (r=0.60, P<0.05), but this was not independent of changes in fat mass. Although changes in leptin levels were not related to changes in RMR or plasma catecholamines after RT with and without weight loss, the increase in insulin action after training and weight loss may be related to the decrease in leptin levels that were mediated by the loss of body fat in the obese, postmenopausal women. International Journal of Obesity (2000)24, 27-32

Early response of cardiopulmonary exercise test(CPET) in patients with locally advanced Non-Small Cell Lung cancer treated with radiation

Background : Patients with locally advanced non-small cell lung cancer are often treated with radiation alone or in combination with chemotherapy. Both modalities have a potentially damaging effect on pulmonary function. In order to examine changes in the cardiopulmonary exercise function of patients with locally advanced non-small cell lung cancer before and after conventional radiotherapy, we conducted a prospective study involving patients with such cancer, that had received radiation therapy. Method : Resting pulmonary function test, thoracic radiographic finding and cardiopulmonary exercise test(CPET) were assessed prior to and 4 weeks following radiation therapy in 11 male patients with locally advanced non-small cell lung cancer. Patient with endobronchial mass were excluded. Results : The forces vital capacity (FVC), forced expiratory volume in 1 second ( and maximal voluntary ventilation (MVV) did not decreased between before and 4 weeks after radiation but the diffusing capacity (DLCO) had decreased by 11% 4 weeks after radiation, which was not statistically significant. No changes in maximal oxygen consumption (max), carbon dioxide production (), exercise time and work load were attributed to radiation therapy. Follow up cardiopulmonary exercise testing revealed unchanged cardiovascular function, ventilatory function and gas exchange. No difference in cardiopulmonary exercise test performance was observed between pre- and post-radiation. Conclusion : Cardiopulmonary exercise function did not decrease within the short-term after the radiation of patients with locally advanced non-small cell lung cancer.