[Cigarette smoking and physical fitness]

Associated Factors of Time Spent Walking for Community-Dwelling Stroke Survivors

BACKGROUND

This study aimed to investigate the factors associated with the time that community-dwelling stroke survivors spent walking.

METHODS

We analyzed the cross-sectional data of 1534 community-dwelling stroke survivors from the Korean National Health and Nutrition Examination Survey. Complex-sample logistic regression analyses were performed to determine the factors associated with insufficient walking time (<90 min/wk). The mean time spent walking was examined according to age, sex, resistance exercise level, and self-reported disability using complex-sample general linear models.

RESULTS

Women (odds ratio [OR] 1.5; 95% confidence interval [CI], 1.0-2.3), current smokers (OR 1.7; 95% CI, 1.1-2.8), insufficient resistance exercise (OR 2.3; 95% CI, 1.5-3.5), and those with rural residences (OR 1.4; 95% CI, 1.0-1.9) were independently associated with insufficient walking time. The mean time spent walking was significantly lower in older adults aged ≥65 years than in young adults aged <65 years (200.0 ± 42.0 min/wk vs 287.2 ± 36.6 min/wk, P = .002), in women than in men (200.9 ± 44.9 vs 286.2 ± 37.7 min/wk, P = .027), and in individuals engaging in insufficient resistance exercise compared with those engaging in sufficient resistance exercise (203.2 ± 36.2 vs 283.9 ± 43.0 min/wk, P = .008). The mean walking time did not vary according to the presence of self-reported disabilities.

CONCLUSIONS

Environmental and personal factors are associated with insufficient walking time in community-dwelling stroke survivors.

Short-Term Cigarette Smoking in Rats Impairs Physical Capacity and Induces Cardiac Remodeling

Despite the strong evidence on the cardiac and renal damages after chronic exposure to cigarette smoke, there is a paucity of data on its short-term effects. The study evaluated the short-term effects of cigarette smoking on left ventricular (LV) remodeling, in vitro myocardial and renal function. Female Wistar rats were randomized to control (C) and cigarette smoking rats for eight weeks. Physical capacity was assessed using an adapted model of exhaustive swim; left ventricle (LV) morphology and function were also evaluated. Renal function was assessed by creatinine clearance and urine protein. The in vitro myocardial performance was analyzed in isolated papillary muscles. Rats exhibited reduced physical capacity after short-term cigarette smoking. Although there was no change on LV function, reduced chamber diameter was found in the smoking group associated with an increased LV wall thickness. There was augmented cardiac mass compared to C that was confirmed by increased cardiomyocyte nucleus volume, but in vitro myocardial performance and renal function were unchanged. A short-term cigarette smoking induces cardiac remodeling without abnormalities in function. The smoking group still preserved renal function and in vitro myocardial performance. However, the reduced physical capacity may suggest an impairment of the cardiac reserve.

Misinterpretation of the Borg's Rating of Perceived Exertion Scale by patients with panic disorder during ergospirometry challenge

INTRODUCTION

The most widely used instrument to measure perceived exertion or exercise intensity is the Borg's Rating of Perceived Exertion (RPE) Scale. Panic attacks are aversive experiences that may be triggered by bodily sensations such as palpitations, breathlessness or dizziness due to increasing autonomic distress, prior sensitisation to panic and fear conditioning. The consequence is catastrophic interpretation of bodily sensations of arousal in general, which can lead to misinterpretation of exertion or exercise intensity.

PURPOSE

To verify the effectiveness of the Borg's RPE Scale as a measure of perceived effort in panic disorder subjects.

METHODS

The study enrolled 72 subjects: the control group (C, healthy sedentary subjects, n=30) and patients with panic disorder (PD, n=42). All subjects were submitted to an ergospirometry challenge. Perceived exertion RPE scores and heart rate at 90% VO2max were compared between groups.

RESULTS

Patients with PD showed lower levels of maximal oxygen consumption, when compared with C group [VO₂max (mL/kg/min): PD=29.42±6.50xC=34.51±5.35; Student's t-test=-3.51; p <0.05]. Furthermore, among PD subjects, the maximum heart rate during ergospirometry challenge was lower than expected [predict max HR (bpm)=200.85±6.33xheart rate test (bpm)=178.86±7.28; Z=-5.64; p<0.05]. Perceived exertion, as measured by RPE, was also overestimated in relation to heart rate at 90% of maximum oxygen consumption compared with controls (RPE90%VO₂max: PD=18.93±0.55xC=16.67±0.60; U=8.00; Z=7.42; p<0.05).

CONCLUSIONS

The present study findings suggest that the Borg's RPE Scale may not be an appropriate measure of subjective exertion among subjects with panic disorder performing a cardiopulmonary exercise test.

Associations of subjective vitality with DNA damage, cardiovascular risk factors and physical performance

AIM

To examine associations of DNA damage, cardiovascular risk factors and physical performance with vitality, in middle-aged men. We also sought to elucidate underlying factors of physical performance by comparing physical performance parameters to DNA damage parameters and cardiovascular risk factors.

METHODS

We studied 2487 participants from the Metropolit cohort of 11 532 men born in 1953 in the Copenhagen Metropolitan area. The vitality level was estimated using the SF-36 vitality scale. Cardiovascular risk factors were determined by body mass index (BMI), and haematological biochemistry tests obtained from non-fasting participants. DNA damage parameters were measured in peripheral blood mononuclear cells (PBMCs) from as many participants as possible from a representative subset of 207 participants.

RESULTS

Vitality was inversely associated with spontaneous DNA breaks (measured by comet assay) (P = 0.046) and BMI (P = 0.002), and positively associated with all of the physical performance parameters (all P < 0.001). Also, we found several associations between physical performance parameters and cardiovascular risk factors. In addition, the load of short telomeres was inversely associated with maximum jump force (P = 0.018), with lowered significance after exclusion of either arthritis sufferers (P = 0.035) or smokers (P = 0.031).

CONCLUSION

Here, we show that self-reported vitality is associated with DNA breaks, BMI and objective (measured) physical performance in a cohort of middle-aged men. Several other associations in this study verify clinical observations in medical practice. In addition, the load of short telomeres may be linked to peak performance in certain musculoskeletal activities.

Efeitos cardiovasculares da abstinência do fumo no repouso e durante o exercício submáximo em mulheres jovens fumantes

OBJETIVO: O objetivo do presente estudo foi verificar o efeito da abstinência do fumo nas respostas cardiovasculares ao exercício físico progressivo submáximo em mulheres sedentárias fumantes. MÉTODOS: A pressão arterial sistólica (PAS) e diastólica (PAD) e a freqüência cardíaca (FC) foram medidas de forma não invasiva em mulheres jovens não fumantes (MNF, n = 7) e fumantes (MF, n = 7), sem e com abstinência do fumo por 24 horas, em repouso, durante a realização do teste submáximo em bicicleta ergométrica e na recuperação. RESULTADOS: Em repouso, a PAD e a FC foram maiores nas MF (76 ± 1mmHg e 86 ± 5bpm) quando comparadas com as MNF (68 ± 2mmHg e 72 ± 2bpm). Após 24 horas sem o tabaco essas medidas foram normalizadas. Durante o exercício, a PAS e a FC aumentaram nos grupos estudados. A PAD foi maior nas MF (~15%) em relação às MNF em todos os estágios do exercício. Na situação de abstinência, a PAD aumentou somente no último estágio de exercício. Na recuperação tanto a PAD quanto a FC foram maiores nas MF, na situação basal e com abstinência de 24h, quando comparadas as MNF. CONCLUSÃO: Estes resultados demonstram que mulheres jovens fumantes apresentam prejuízo em parâmetros hemodinâmicos em repouso e em resposta ao exercício submáximo, os quais, podem ser em parte revertidos pela abstinência em curto prazo do uso do tabaco.

Effects of habitual smoking on cardiorespiratory responses to sub-maximal exercise

The effects of habitual cigarette smoking on cardiorespiratory responses to sub-maximal and maximal work were evaluated in nine adult nonsmokers and nine smokers with a mean age of 33 yr. A maximal treadmill test was followed by three tests at 45, 60 and 75% of each subject's VO(2)max. Compared to nonsmokers, the habitual smokers had a non-significantly lower VO(2)max in L/min and per lean body mass (9 and 6%, respectively), but had higher %fat (p<0.01), resulting in a significantly lower VO(2)max per kg body wt (13%, p<0.03). Maximal exercise ventilation (V(E)) was 16% lower in smokers. During sub-maximal work at equivalent exercise stress levels in the two groups, the V(E)/VO(2) ratio was higher in smokers by an average of 11% because VO(2) was lower and the respiratory exchange ratio values were significantly elevated in smokers at 75% of VO(2)max. Blood lactate concentrations in smokers were higher as workloads increased and O(2) pulse (VO(2)/HR) was significantly lower throughout, indicating reduced O(2) extraction, probably due to carbon monoxide. The resting HR was significantly higher in smokers and the HR recovery following all three submaximal exercises was significantly slower in smokers. These results show that detrimental cardiorespiratory effects of chronic cigarette smoking in apparently healthy individuals are evident at moderate exercise levels as reduced gas exchange efficiency in lungs and muscles.

Occupational physical activity is related to physical fitness in young workers

PURPOSE

We evaluated the association between occupational physical activity and fitness in young workers, taking into account leisure-time physical activity, body size, and smoking.

METHODS

The study population comprised 2188 men and 1987 women, members of the Northern Finland birth cohort 1966, who participated in the 1997-1998 follow-up survey and were employed at the time of the survey. Cardiorespiratory fitness was measured by a 4-min step test and muscular fitness by tests of maximal isometric handgrip and isometric trunk extension. Information on occupational and leisure-time physical activity and smoking was obtained by questionnaire, and body height and weight were measured during medical examination. The data were analyzed by analysis of variance and Cox regression.

RESULTS

Men doing heavy physical work scored better in cardiorespiratory fitness, handgrip strength, and trunk muscle endurance than men doing lighter work; the finding for cardiorespiratory fitness was similar in women. The associations were independent of leisure-time physical activity, body weight and height, and smoking.

CONCLUSION

A positive association was found between heavy physical work and a high level of fitness in young workers. Due to limitations of the study setting, causality cannot be asserted, but a training effect of heavy work would not seem unreasonable. Previous studies have suggested a reversal of the positive effect of heavy work on fitness with advancing age. Therefore, regular monitoring of workers' fitness at an early phase is justified to enable assessment of workers' capacity for heavy jobs and any possible need for fitness-improving activities.