Exercise and Mortality - How Many Steps Translate Into Longer Life?
Fitness trackers can be a convenient way to monitor the number of steps taken every day. Some insurers have even started using them as a proxy for good health, selling life cover to people who are already fit and who track their steps. They may even reward policyholders’ physical activity with lower premiums and other incentives.
The assumption is that regular exercise, especially the number of steps taken, is a predictor of lower mortality. Exercise is known to confer health benefit by improving mental health, reducing cardiovascular risk and cancer mortality. The question is, how many steps might lead to a longer life?
Adult walking cadence is 100 steps per minute, a rate that demarks the lower end of moderate intensity exercise. The WHO suggests an ambitious minimum of 150 minutes of “moderate-intensity” aerobic physical exercise throughout the week, or 75 minutes of vigorous-intensity, or a combination (setting aside recommendations for muscle strengthening).1 Public health authorities across the world have adopted these guidelines to help people improve health, build stamina and burn excess calories.
Manufacturers of fitness trackers and wearable technology, ever since the Japanese pedometer that came out for the 1964 Olympics, have commonly set the goal at 10,000 steps per day, a marketing ploy not rooted in science or WHO guidelines. Although this "10,000 steps" goal varies greatly by leg length and gait, it translates into roughly 5 miles a day for the average person and remains a considerable distance, especially considering that the average British adult walks 3,000 to 4,000 steps daily.2 The figure encourages sedentary people to move but isn’t a magic number on a doorway to health nirvana. Even 5,000 steps per day could be too high for some older adults or people with chronic illness, but small increases will confer health benefits.
It’s also important to distinguish between incidental and session-based physical exercise. Incidental exercise is the result of steps taken during the course of the day to get us from A to B, but it neither accounts for the pace nor intensity of the exercise or the true level of fitness. A three-hour workout “session” requires a much higher level of fitness than just walking, not to mention a significant level of motivation.
Insurance products that discount for steps walked each day are likely to have broader appeal than those that mandate "session-based" exercise. Asking additionally for, say, three hours per week of sweat-inducing exercise could literally be a step too far. Those unaccustomed to such levels of exercise are likely to conclude that this insurance product is not designed with them in mind.
Recent evidence suggests activity tracking brings no immediate measurable health benefit but this misses the point.3 Regular exercise has benefits that are not necessarily related to easily measurable variables such as weight and blood pressure. It’s important to understand that long-term outcomes are what are important for insurers.
Although the WHO recommends 150 minutes of moderate intensity exercise a week for ages 18–64, a critical review of the literature indicates that just half this level still brings marked health benefits.4 This suggests insurers could lower the bar and design life insurance programmes that would also appeal to older people or those with chronic disease or restricted mobility, who may otherwise rule out buying a policy explicitly linked to fitness.
For more blogs on how technology is changing life insurance, click here.
- Finkelstein, E. et al (2016) Effectiveness of activity trackers with and without incentives to increase physical activity (TRIPPA): a randomised controlled trial, The Lancet Diabetes & Endocrinology 2016, DOI:10.1016/S2213-8587(16)30284-4.
- Warburton D and Bredin S,(2016) Reflections on Physical Activity and Health: What Should We Recommend? Canadian Journal of Cardiology 2016; 32 (4): 495 DOI: 10.1016/j.cjca.2016.01.024.