Physical activity is needed to enjoy a long and healthy life – this statement is beyond doubt and has been repeatedly confirmed by countless studies. However, it is harder to find an answer to the question of how many minutes exactly a week should be spent exercising in order to enjoy longevity. A study funded by the Taiwan Department of Health Clinical Trial and Research Center of Excellence and National Health Research Institutes decided to check whether the recommended 150 minutes of exercise per week is the optimal amount of time that will increase one’ chances of reaching old age.

This prospective cohort study took place in Taiwan. A total of 416,175 people (216,910 women and 199,265 men) participated in the study. It lasted from 1996 to 2008, and the participants were observed from 5 to 8 years. For each of the groups, the mortality risk indicator was calculated and compared with the inactive group. The life expectancy characteristic of each group was also estimated and the health benefits of the different amounts of exercise performed by each group were indicated. As it turns out, the results of the study were not influenced by factors such as gender, age of the respondents or even whether the person is at risk of cardiovascular diseases.[1] It is often suggested by scientists that at least 10,000 steps per day should be taken for the sake of good health. But why is such an amount recommended and what are the actual health benefits? To determine this, it was decided to analyze three cohorts conducted in Tasmania to investigate the relationship between the number of steps performed daily and all-cause mortality and what effect the change in activity has on this result.The data were taken from the results of The Australian Diabetes, Obesity and Lifestyle (AUSDIAB) study, The Tasmanian Older Adult Cohort (TASOAC) study and The Tasmanian Study of Cognition and Gait (TASCOG) study. The AUSDIAB study involved 1,136 people over the age of 18 and the main aim of the study was to investigate diabetes, The TASOAC study involved 1,061 people between the ages of 50 and 80 and the TASCOG participants were in the 60-86 age group. The relationship between the number of steps performed daily and own activity was also studied. Interestingly, these two factors were only poorly related to each other. Even weaker was the relationship between the number of steps performed per day and time spent on moderate physical activity. Most of the scientific work focuses on determining the optimal time to be devoted to physical activity. According to The 2008 Physical Activity Guidelines for Americans it should be at least 150 minutes of moderate activity or 75 minutes of intense activity per week. However, it is rarely asked whether very high physical activity in leisure time enhances the benefits or is rather harmful, and what should be the upper limit. In order to find out how high levels of leisure-time activity affect mortality risk and whether a limit should be set, data from six different studies [the National Institutes of Health (NIH)-AARP Diet and Health Study, The CPS II, CLUE II, the U.S. Radiologic Technologists (USRT) Study, the Women’s Health Study (WHS) and the Women’s Lifestyle and Health Study (WLHS)] were collected and analysed. A total of 661,137 people aged 21 to 98 years were examined. The subjects were monitored for an average of about 14 years. As it turned out, people who exercise 10 times more in their free time than recommended were not exposed to any negative effects related to this. The mortality risk calculated for them was reduced by 39%. They were also much less likely to die as a result of cancer, as the risk was 31% lower compared to those who were not active at all. However, as shown, no additional benefits were demonstrated for people with extremely high physical activity. This was also sufficient to minimize the risk of death from CVD. For both women and men the results were very similar. According to the study, there is no upper limit that determines the highest level of physical activity that should be performed in leisure time.[3]

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