STUDY OF PHYSICAL ACTIVITIES IN THE BLSA

在过去的一年中，我们报道了通过VO2max估算的体力活动与心血管健康之间的关系。根据目前公认的特定体育活动的氧气利用估计，巴尔的摩老年纵向研究受试者进行100次活动所花费的时间被转换为METS*分钟。代谢当量是一种标准的方式来表示氧气利用调整身体大小。然后将100项活动分为三类：低水平活动（<4 METS），中等水平活动（4-6 METS）和高水平活动（bbb60 METS）。心血管健康与高水平运动（r= 0.32）、中等水平运动（r= 0.15）、体型（BMI） （r=- 0.32）和年龄（r=- 0.58）显著相关。在对这些变量的多变量分析中，身体活动独立解释了最大摄氧量1.6%的方差，而与年龄和体重指数的方差约为10%。使用回归模型，我们估计对于一个普通人来说，要增加10%的最大摄氧量，每天需要35-40分钟的高强度运动和150分钟的中等强度运动。这些计算结果支持了最近外科医生建议的日常体育活动的总体概念。我们已经研究了心血管健康水平或身体活动是否是男性死亡率的独立危险因素。由最大摄氧量（VO2max）评估的心血管健康是导致全因死亡率和心脏死亡率的一个重要独立因素。体育活动很重要，但与健身的程度不同。有趣的是，高强度的体力活动是老年男性（60岁至60岁）的独立危险因素，而不是年轻男性，而心血管健康在所有年龄段都很重要。如果体育活动对生存和健康很重要，我们应该根据绝对尺度来判断活动水平，还是根据年龄调整的尺度来判断？我们已经在BLSA中探讨了这个问题，并发现通过使用绝对尺度，身体活动水平存在与年龄相关的下降。使用年龄调整量表，体力活动水平随着年龄的增长而增加。虽然相对量表在检查活动和健康之间的关系方面可能有价值，但它们会导致关于老年人身体能力的错误结论。

Over the past year, we have reported the relationship between physical activity and cardiovascular fitness as estimated by VO2max. Based on currently accepted estimates of oxygen utilization for specific physical activities, the time Baltimore Longitudinal Study of Aging subjects spent doing 100 activities was converted to METS*minutes. METS is a standard way to express oxygen utilization that adjusts for body size. The 100 activities were then divided into three categories: low level activity (<4 METS), moderate level activity (4-6 METS), and high level activity (>6 METS). Cardiovascular fitness was significantly correlated with high level activity (r=.32), moderate level activity (r=.15), body size (BMI) (r=-.32), and age (r=-.58). In multivariate analysis with these variables, physical activity independently explained 1.6% of the variance in VO2max while sharing about 10% of the variance with age and BMI. Using the regression models, we estimate that for an average individual to increase their VO2max 10% requires 35-40 minutes a day of high level activity and 150 minutes a day of moderate level activity. These calculations support the general concept of the recent Surgeon General recommendations for daily physical activity. We have examined whether the level of cardivascular fitness or physical activity are independent risk factors for mortality in men. Cardiovascular fitness, as assesse by VO2max, is a strong independent contributor to both all cause and cardiac mortality. Physical activity is important, not to the same degree as fitness. Of interest, high intensity physical activity was an independent risk factor in older men (>60 years) but not younger men, while cardiovascular fitness was important at all ages. If physical activity is important for survival and fitness, should we judge the levels of activity based on an absolute scale, or on an age-adjusted scale. We have explored this question in the BLSA, and found that by using an absolute scale, there is an age-associated decrement in the levels of physical activity. Using an age-adjusted scale, the level of physical activity increases with increasing age. While relative scales may be of value in examining the relationships between activity and well being, they lead to the wrong conclusions regarding the physical capacity of the elderly.