Most countries in the world will by the year 2050 experience a large demographic change, leading to an increase in the proportion of older adults. This is expected to increase health related costs. Physical activity is shown to be a key factor in the prevention of lifestyle-related diseases, but there is less research on physical activity among older adults compared to the general population. In addition, there are few long-term, randomized exercise intervention studies among healthy older adults.
Today is the public defense of my PhD about the Generation 100 study, and the thesis is based on three research papers. Paper one aimed to describe the design, methodology and initiation of a randomised controlled trial entitled the Generation 100 study, evaluating the effect of long-term exercise training on health, longevity and physical activity levels among older adults. Paper two aimed to describe physical activity levels in older adults, using both relative- and absolute intensity thresholds for activity monitors (accelerometer). Paper three aimed to increase the knowledge about the background factors associated with accelerometer-measured physical activity in older adults.
Read more about the Generation 100 study here!
The Generation 100 is outlined in detail in paper 1. It began in 2012 and will continue until 2018. The study included 1,567 people aged 70-77 years, residing in the municipality of Trondheim, Norway. Participants underwent thorough examinations, including measurement of physical activity and cardiorespiratory fitness (maximal oxygen uptake). They also filled out questionnaires. Participants are followed-up at 1-, 3- and 5 years of the study. Participants were randomly assigned to a control group or to either a moderate- or high intensity endurance exercise group required to train two times per week.
The results from paper 2 showed that the activity level in 1219 Norwegian older adults was higher than in comparable countries, but very similar to a Norwegian national survey from 2008-2009. Females had a higher overall activity, and spent more time in higher relative intensities, compared to males. Overall activity and time in the near-max relative intensity decreased with age. Older adults with higher levels of cardiorespiratory fitness were also more active than those with low- and medium levels of cardiorespiratory fitness. We found that the use of relative intensity thresholds, adjusted for the participants’ gender and fitness, resulted in higher proportions (79 percent) of older adults meeting physical activity recommendations, compared to the use of a traditional absolute intensity threshold (29 percent).
The results from paper 3 showed that 9 out of 14 background factors explained 27% of the variance in overall physical activity among 850 older adults. Activity level was associated with demographic, environmental and biological factors. Cardiorespiratory fitness, gender and season were the single factors most strongly associated with overall activity. The study was, to our knowledge, the largest study of background factors for physical activity among older adults that has combined accelerometry and directly measured maximal oxygen uptake.
Hallgeir Viken, PhD student at CERG