In order to prevent the installation of a deleterious sedentary lifestyle among seniors, public health policies have been put in place to promote physical activity, an essential element for maintaining the body in good health. Researchers from Inserm and Université Paris Cité within the Center for Epidemiology and Statistics Research, using data from 3,896 participants in the Whitehall II cohort, looked at the impact of individual factors (socio -demographic, behavioral and health) on the practice of daily physical activity during aging. These works to be published in Open JAMA Network highlight the complexity of the individual barriers to an active lifestyle among seniors and propose to better take it into account to redefine public health policies.
By maintaining many essential functions that prevent chronic disease and mortality, physical activity is one of the keys to healthy aging. If the current recommendations are to achieve 21 minutes per day of moderate to intense physical activity, and to reduce the time spent sitting (sedentary lifestyle), few people actually follow them, especially among the oldest. In addition, public health messages aimed at seniors take little account of individual factors – environmental and personal – that are likely to limit the adoption of an active lifestyle.
A research team led by Séverine Sabia, Inserm researcher at the Epidemiology and Statistics Research Center (Inserm/Paris Cité University) studied the factors influencing physical activity and sedentary lifestyle during ageing.
Scientists were interested in data from the British Whitehall II cohort : 3,896 participants aged 60 to 83 wore a measuring device (accelerometer) for 9 days in 2012-2013 to continuously record data relating to the intensity and duration of their daily physical activity. In addition, their socio-demographic data (age, sex, ethnicity, professional occupation, marital status), behavioral (consumption of tobacco, alcohol, fruit and vegetables), health (body mass index, quality of life , chronic diseases) and physical activity were collected between 1991-1993 and 2012-2013, i.e. over a period of 20 years before the accelerometer measurement.
The researchers considered 3 types of physical activity intensity: sedentary (low-energy activity in a seated or lying position), light-intensity physical activity (slow walking, for example) and moderate to vigorous physical activity (swimming, cycling, etc.).
The first finding of the research team was that men spend more time in sedentary activity and in moderate to vigorous activity than women, who spend more time than men in light activity.
Depending on the factors that were studied, a longer duration of sedentary time during aging was reflected differently in the duration of other types of physical activity intensity. For example, compared to people living with a partner, people living alone spend on average 11 minutes more in sedentary activities, mainly at the expense of light activity time. On the other hand, even if a difference of 5 years of age results in a similar increase in sedentary time, this comes at the expense of moderate to vigorous activity time – which corresponds to more than half of the daily time. recommended (21 minutes).
All the behavioral factors seem to impact the time spent in the different intensities of physical activity. The largest difference is found in male smokers who spend 37.4 more minutes sedentary per day, at the expense of 23.3 minutes of light activity and 14.1 minutes of moderate-to-vigorous activity (i.e. the 2 /3 of the recommended time for the latter). However, among women who smoke, the increase in sedentary time is rather at the expense of moderate to high activity.
Among the factors relating to health status, poor general condition, the presence of chronic diseases and obesity are associated with a significant increase in sedentary time.
Obesity in particular shows the largest differences: at the same age, obese people are sedentary 50.7 minutes longer per day than people with a normal body mass index, at the expense of 28.6 minutes of activity of light intensity and 22.1 minutes of moderate-to-vigorous physical activity – the full time recommended for the latter.
In general, in women, almost all the factors have an impact on the time spent in the different intensities of physical activity, in a similar way but globally less contrasted than in men.
“ We wanted to know if the barriers to the practice of physical activity among seniors were already present earlier in life and found that this was the case. Living alone, being overweight or obese, chronic diseases, physical weakness or poor lifestyle at average ages of 50 and 60 were associated with low activity levels in old agesays Mathilde Chen, lead author of the book. We were also able to observe a grouping of behavioral risk factors: people who are more sedentary tend to smoke and eat less fruit and vegetables. This work reflects the complexity of the determinants of an active lifestyle among seniors. »
Séverine Sabia, investigator of the study, concludes: “ In the fight against the health impacts of a strong sedentary lifestyle among seniors, this work provides arguments in favor of targeted prevention strategies, integrating all the components of physical activity and behaviors related to a healthy lifestyle. , and aimed as early as possible at people most likely to be inactive as they age. »
 The Whitehall II cohort was set up between 1985 and 1988; 10,308 British participants (67% male) aged 35-55 were recruited and have been followed ever since.