No need to meekly accept the disapproving moral sanction of others when you do not exercise enough. If you do not like to exercise blame it on your genes.
A sedentary lifestyle remains a major threat to health in contemporary societies. To get more insight in the relative contribution of genetic and environmental influences on individual differences in exercise participation, twin samples from seven countries participating in the GenomEUtwin project were used.
Self-reported data on leisure time exercise behavior from Australia, Denmark, Finland, Norway, the Netherlands, Sweden and United Kingdom were used to create a comparable index of exercise participation in each country (60 minutes weekly at a minimum intensity of four metabolic equivalents).
Modest geographical variation in exercise participation was revealed in 85,198 subjects, aged 19–40 years. Modeling of monozygotic and dizygotic twin resemblance showed that genetic effects play an important role in explaining individual differences in exercise participation in each country. Shared environmental effects played no role except for Norwegian males. Heritability of exercise participation in males and females was similar and ranged from 48% to 71% (excluding Norwegian males).
This result suggests one potential solution for the tendency of people in modern societies to get insufficient exercise: Genetically engineer offspring to get more joy from exercise. Also, identification of the genetic variations that contribute to the urge to exercise could lead to development of drugs that make exercise more enjoyable.
But genetic engineering will likely lead to the development of methods to reduce the need for exercise. Look at how anabolic steriods increase muscle mass build-up in response to exercise. We'll eventually have safer ways to control extent of muscle mass. We'll also gain complete control of appetite and find ways to cause the body to burn off excess fat. We'll also find lower exercise ways to produce other physiological benefits that we now gain from exercise.
Since an increasing fraction of all physical labor is automated we really need to find ways to adapt our metabolisms to the changes in our environment which are the results of our technology. This problem is only going to get worse as robots take over cleaning the house, mowing the lawn, and other physical chores us desk jockeys and drivers still do. Biotechnology will provide the solutions.