Détermination de l'activité physique par questionnaire: validation du questionnaire autoadministrable de Baecke

Prospective studies assessing physical activity support the hypothesis that regular exercise can decrease the risk of ischemic heart disease and reduce other cardiovascular disease risk factors. One reason for the lack of strong consensus may be the difficulty in assessing physical activity. In epidemiological studies, questionnaires and interviews appear to be the most common and most useful methods to assess physical activities. Of particular interest is the Baecke questionnaire allowing the calculation of indices for work, sport, and leisure time. In this study, the Baecke questionnaire was tested on 118 French males aged 30–58 years. Under our experimental conditons, only sport and leisure-time index were calculated. The results show that indices both for sport (IAS) and leisure time (IAL) were positively related to maximum oxygen uptake (VO₂max); r = 0.526 and r = 0.436 respectively, P < 0.001. Multiple regression analysis showed a positive relationship between VO₂max and the sport and leisure-time index (R² = 0.38; P < 0.001). Moreover, a more complete multiple regression procedure was performed in order to predict VO₂max. The fitting model was of the form VO₂max = 36.09 + 2.44* (IAS) + 3.37* (IAL) − 0.19* (age) − 0.31* (body fat) + 0.15* (muscular endurance) (P < 0.001; R² = 0.53). In summary, this study showed for the first time a statistically-significant relationship between sport and leisure-time index, and maximal oxygen uptake. However, although a significant linear model was fitted relating VO₂max to several independent factors (anthropometric and physiologic parameters), the prediction of VO₂max apart from large epidemiological studies, was unsatisfactory. This does not however reject the usefulness of the Baecke questionnaire for the measurement of habitual physical activity.     

Vieillissement et désaturation oxyhémoglobinée du sportif

A extreme athlete can be defined as an athlete able to exceed the limit of one function in such a way that failure of another function appears. For example extreme athletes in endurance events are able to exceed the normal limits of cardiac output but show a hemoglobin desaturation by the end of exhaustive exercise. Usually, these athletes have had a maximal oxygen uptake (O₂ max) greater than 65 ml·min⁻¹. The aim of this study was to determine whether hemoglobin desaturation occurs in master athletes and whether aging facilitates this phenomenon. Nine master athletes aged 62–75 participated to this study. They practised leisure cycling 5000 to 14000 km per year. Hemoglobin saturation was measured non-invasively using the transcutaneous method during both incremental exercise until exhaustion and constant load exercise at 70% and 90% of O₂ max for a 15 min period. We considered that there was a desaturation if SaO₂ decreased by 4%. During maximal incremental exercise we observed desaturation in six subjects. These results were confirmed during constant load exercise at 90% of O₂ max. It is interesting to note that one of the subjects, whose desaturation was 8% during incremental exercise, showed a desaturation of 16% at the 15th minute of constant load exercise at 90% O₂ max. In our master athletes this desaturation was observed for O₂ max and pulse oxygen values respectively equal to 1/2 and 2/3 of the values of young athletes. Aging thus seems to facilitate the mechanisms of athlete's desaturation. These mechanisms are highly speculative. One can, however, suspect the role of relative hypoventilation, a ventilation-perfusion inequality, and a diffusion limitation. A decrease of red blood cell transit time in the pulmonary capillary may also play a role, as there is a decrease in pulmonary capillary volume in master athletes over 60 years and that maximal cardiac output does not seem to decrease with age.     

高原移居者在3680m和4350m高原不同时间的体力指标变化

为研究高原低氧环境对人体的影响，测试了移居高原（海拔３６８０ｍ和４３５０ｍ）不同时间的受试者的基础和体力指标，并与海拔３６８０ｍ地区的藏族世居者进行比较。研究发现，低氧对身高、体重、肺活量、握力、背力、仰卧起坐、俯卧撑和６０ｍ计时跑等无明显影响。晨脉在进入高原初期较高，１５月后恢复正常。移居者１０００ｍ跑成绩低于世居者，高海拔成绩不如低海拔。世居者Ｖｏ２ｍａＸ和ＨＲｍａｘ与平原人相比，有明显区别，移居者居住７～１５月后，此两项指标可接近世居者水平，高海拔者则相对较低。     

高原人体体力测试及相互比较

本文研究了平原人移居海拔3680m后,不同时间体力状况,并与条件相近的藏族世居者进行了比较。研究结果表明,移居者的屏气时间较短,表明其缺氧耐受力低。低氧环境对60m跑和握力等无氧运动项目的影响不大。世居者与平原人相比,Vo_2rmax等指标均低于平原人,表明即使对低氧环境产生习服的人体,也不可能达到平原水平,机体的代偿调节能力是有限的。移居者的Vo_2rmax和HBmax等经过7～15个月的适应,可接近世居者水平。但1000m跑成绩大大低于世居者,可能是两种人群对Vo_2rmax的利用率不同引起。     

Criterion validity of a two-kilometer walking test for predicting the maximal oxygen uptake of moderately to highly active middle-aged adults

This work examined whether prediction models based on a 2-km walking test are valid for predicting the Vo_2max of middle-aged, healthy, moderately to highly physically active adults. Sixty-seven 35- to 45-year-old moderately active men and women and 44 35- to 55-year-old healthy men who participated regularly in marathon-long sports competitions were studied. Vo_2max was determined in an uphill walk-run on a treadmill. The 2-km walking test was conducted on a flat outdoor course. The subjects walked the distance as fast as they could. Walking time, heart rate at the end of the walk, age and body mass index were entered in the prediction formulas as established in the original study. The total errors of prediction and the correlation coefficients between the measured and predicted Vo_2max (ml-kg⁻¹ min⁻¹) for the moderately active women and men and for the competitors were 5.2, 5.7 and 7.7 ml kg⁻¹ min⁻¹ and 0.55, 0.79 and 0.60, respectively. The measured relative Vo_2max was slightly underpredicted in all groups. The results suggest that the 2-km walk test is a reasonably valid test of maximal aerobic power for moderately fit men and women, but less valid for very fit individuals.     

Longevity of soccer players: an investigation of all German internationals from 1908 to 2006

Leisure-time physical activity is associated with better health and a reduced risk of all-cause mortality. It is unclear if this association is also present with a high level of physical activity as it is found in professional athletes. In a population-based retrospective cohort study, we compared the survival experience of all soccer players participating for Germany in international matches between 1908 and 2006 to that of the general population. To summarize survival experience, we calculated cumulative relative survival ratios (RSRs) from a life table. We included data of 812 international players, of which 428 (=52.7%) died during follow-up. In all 13 intervals, cumulative observed survival was smaller than cumulative expected survival, resulting in cumulative RSRs being <1. The cumulative RSRs are statistically significantly different from 1 in all but the last interval. This impaired survival experience of the internationals translates into a loss of median residual lifetime of 1.9 years [95% confidence interval: 0.6, 3.2] years at the entry time into the cohort. This loss is mainly driven by the mortality of internationals from the earlier half of the observation period. Reasons for this might be poorer medical care in former times, internationals being killed in action during World War II, and a changing distribution of causes of death during the 20th century.     

高原士兵体能主要评价指标的选择

本文在作者研究结果的基础上，结合文献资料，提出了评价高原士兵体能的主要指标，认为身高，体重，肺活量，背力，立定跳远和俯卧撑等指标，由于受低氧因素的影响不大，仍选用平原测定方法和评价标准为宜。但低氧对有氧运行水平有影响，海拔越高，影响越大，因此，将海拔３０００～４５００ｍ分为三个高度段，分别评价相应高度段士兵的有氧运动能力，以拉萨（３６８０ｍ）和错那（４３５０ｍ）的受试者所测数据为基础，提出了３５０     

Skeletal muscle fibre types in teenagers: relationship to physical performance and activity

Human skeletal muscle consists mainly of 2 types of fibres denoted type I (slow twitch) and type II (fast twitch). The aim of this investigation was to study skeletal muscle fibre characteristics together with physical performance, physical activity and interest in different physical activities, and the relationships between these variables among students in grade I in high school. Sixty-nine boys and 47 girls at the age of 16 were studied. The relative proportion of type I fibres (type 1%) in vastus lateralis was approximately 50% for both boys and girls and the interindividual variation was large, more so for boys than for girls. The muscle fibre areas for all fibre types were larger in boys than girls and the relationships between the sizes of the areas of type I, type IIA and type IIB differed between the sexes. The muscle enzymes succinate dehydrogenase, 3-hydroxyacyl-CoA-dehydrogenase and phosphofructokinase were all on average higher in boys than girls; the only significant difference was in succinate dehydrogenase. There was a positive correlation between performance in a 9-min run and type 1%. for boys but not for girls. Multiple correlation analysis indicated that factors determining the performance in the 9-min run were maximal oxygen uptake and type I% for boys, and maximal oxygen uptake but not fibre types for girls. The attitude to cross-country running was positively correlated with the type I% for boys but not for girls. There was a stronger positive correlation between degree of physical activity and type I% for boys than girls. In conclusion, stronger correlations between muscle fibre characteristics and physical performance, physical activity and interest in physical activity were found for boys than for girls.     

不同海拔高度移居者体力变化的研究

采用直接法测试最大摄氧量(Vo_2max)评价心肺功能,用WHO—NCTB评价作业工效。结果表明:移居者空运进入3680m高原后,早期体力下降明显,Vo_2max下降23％,经7～15月适应后,体力可逐步恢复,达到稳定,但Vo_2max仍比平原值低7.97％。4350m移居者各项指标均较3680m移居者低,7月后已达稳定,但Vo_2max比平原下降21％。低氧时3689m移居者作业工效的影响,表现在反应速度变慢,工效下降,而4350m移居者已开始累及记忆功能,提示低氧的蓄积效应。     

Coronary heart disease risk factors in middle-aged former top-level athletes

A cross-sectional study was conducted to determine the impact of previous athleticism on coronary heart disease (CHD) risk factors in 168 middle-aged men and 147 middle-aged women in Estonia. Participants were divided into four groups: physically active ex-athletes (AA), sedentary ex-athletes (SA), recreational exercisers (RE), and non-exercisers (NE). The Sharkey's questionnaire was applied to determine the CHD risk factors, health habits, medical, safety, personal, psychological and women's risk factors scores. Anthropometric characteristics, resting systolic and diastolic blood pressure values (SBP, DBP), and physical working capacity (PWC₁₇₀) were measured. Concentrations of total cholesterol (CHOL), high-density lipoprotein cholesterol (HDL-C), triacylglycerols (TG), and glucose were determined. Low-density lipoprotein cholesterol (LDL-C) and HDL-C/CHOL ratio were computed. From the questionnaire results, significant differences in CHD risk scores in both sex groups in favour of AA and RE were found. DBP in men was significantly higher in SA, and SBP in women was significantly higher in NE in comparison with other groups. PWC₁₇₀ and PWC₁₇₀/kg was highest in AA and lowest in NE in both sex groups. There were no significant differences for blood biochemical parameters between women's groups. In men, AA had a lower CHOL level in comparison with SA and NE, and lower concentrations of TG and LDL-C than other groups. AA and RE had a higher HDL-C concentration and HDL-C/CHOL ratio in comparison with the other groups. In conclusion, differences in CHD risk factors were related to current physical activity, and were more expressed in men than in women.     

最大摄氧量间接测定方法的探讨

54名男受试者(20.3±1.8岁)分别完成了亚极量踏阶运动。用Shephard,Margaria和汪济民的计算公式及Maritz的回归方程法,根据亚极量踏阶运动的心率(HR)和氧耗量(Vo_2)间接估计出最大摄氧量(Vo_(2max))。三种计算公式估计的Vo_(2max)与回归方程法估计值进行了比较。结果表明,汪济民计算式估计的Vo_(2max)更接近回归方程法的估计值。预测Vo_(2max)的亚极量运动的适宜运动强度为70～80%Vo_(2max)。另外,我们还导出由体重和踏阶速度(阶高40cm)推算Vo_2的公式,Vo_2(L/min)=0.02715体重(Kg)+0.01143踏阶速度(次/min)—1.1207。     

Both poor cardiorespiratory and weak muscle fitness are related to a high concentration of oxidized low-density lipoprotein lipids

Good physical fitness is associated with favorable serum lipids. Oxidized low-density lipoprotein (ox-LDL) could be even more atherogenic than serum lipids. We studied the association of ox-LDL and serum lipids with physical fitness. Healthy young (mean age 25 years) men (n=846) underwent maximal oxygen uptake (VO(2max) ) and muscle fitness index (MFI) tests and completed a leisure-time physical activity (LTPA) questionnaire. Age (ANCOVA1), age+waist circumference+systolic blood pressure+fasting blood glucose+smoking (ANCOVA3) were used as covariates. The groups with the lowest VO(2max) , MFI and LTPA had 23%, 16% and 8% higher concentrations of ox-LDL than the groups with the highest VO(2max) (P<0.0001), MFI (P=0.022) and LTPA (P=0.039) groups, respectively. Subjects with poor fitness (low VO(2max) or low MFI) or low LTPA had elevated levels of ox-LDL/high-density lipoprotein (HDL)-cholesterol, total cholesterol, LDL-cholesterol, triglycerides and a low level of HDL-cholesterol (ANCOVA1, in all, P<0.05). Furthermore, low VO(2max) is associated with a high level of ox-LDL/HDL-cholesterol and triglycerides, and with a low level of HDL-cholesterol (ANCOVA3, in all, P<0.05). Also, subjects with low LTPA had a high ratio of ox-LDL/HDL-cholesterol (ANCOVA1, P=0.001). In conclusion, both poor fitness (both low VO(2max) and low MFI) and low LTPA are associated with a higher concentration of ox-LDL lipids and serum lipids, which may indicate a higher risk for atherosclerosis.     

Salmeterol and physical performance at -15°C in hghly trained nonasthmatic cross-country skiers

The aim of this double-blind. placebo-controlled, cross-over study was to investigate possible improvement in physical performance at an ambient temperature of −15°C by an inhaled dose of 50 μg salmeterol in 8 highly trained nonasthmatic cross-country skiers. FEV₁ was measured before, during and after the treadmill exercise protocol, which consisted of a warm-up run. runs of 10 min at 90%, and 5 min at 80% V O_2max, followed by a timed run to exhaustion. Despite a significant improvement in FEV₁, salmeterol did not have a beneficial effect on heart rate, blood lactate concentration, respiratory exchange ratio, oxygen uptake or minute ventilation during the exercise protocol. Running time to exhaustion was not significantly different from placebo. This lack of enhancement of exercise performance in healthy endurance athletes further supports the recent approval of salmeterol for prophylactic use by asthmatic athletes during training and competition.