How Much is Too Much?

There has been some reporting recently on a study published in the Journal of the American College of Cardiology (JACC) which claims that too much "jogging" is as bad as none at all. The Copenhagen City Heart Study claims that the best health results in terms of reduced all-cause mortality were experienced by joggers who ran for between 1 hour and 2.4 hours per week. According to this study, those who ran more often and more strenuously had as high risk of all-cause mortality as those who did no exercise at all.

Looked at like that this is of great comfort to those who belong in that group.


There has been some reporting recently on a  study which claims that too much "jogging" is as bad as none at all. The study, published in the Journal of the American College of Cardiology (JACC), reports that in the Copenhagen City Heart Study the best results in terms of reduced all-cause mortality were experienced by joggers who ran for between 1 hour (light) and 2.4 hours (moderate) per week, with a frequency of no more than 3 times per week. According to this study, those who ran more often and more strenuously had as high risk of all-cause mortality as those who did no exercise at all. Looked at like that, this is of great comfort to those who belong in that group.

 

And as usual, the situation is a bit more complex.

 

Firstly, the most important conclusion of the study is that there are significant health benefits in terms of life expectancy from exercise - even if you do as little as one hour a week of jogging, and even if that is at a fairly slow pace. Given the fact that out of the 13,000 subjects questioned for the study less than 25% partook in exercise at all, another conclusion would be that there are a lot of people who could do themselves a great deal of good with not much effort.

 

And even though this study showed no benefits in terms of a reduced likelihood of early death among those jogging more than 2.4 hours per week, you can turn that on its head and say that nor was there any evidence of an increased risk of dying early among those exercising more frequently and for longer - and if you enjoy exercise, how bad is that?

 

Moreover, in an editorial accompanying the report by another researcher who had authored a different study on the same subject himself in 2014, DC Lee of Iowa State University's College of Human Sciences did not entirely endorse the report's conclusions. Lee's study, also published in JACC, did show the same significant level of health benefits at even fairly low levels of exercise. But it also showed that the benefits extended to those who ran for up to 3 hours a week, with a frequency of up to 6 times per week and claimed not only that the benefits increased up to that level of exercise but that they were highest for the runners at that level. Furthermore, Lee expressed concerns about the limitations of the Copenhagen study's conclusions due to the extremely small number of participants in the study who ran more than 4 hours per week - only 47 out of the 13,000. And out of the 13,000 subjects, only 80 of them ran more often than three times per week.

 

Another limitation in the study brought up by Lee was that it paid no attention to other forms of exercise - such as strength training, one of the most important aspects of fitness in age, which brings us neatly on to another piece of recently published research.

 

A study from the US Center for Disease Control reported that almost 20% of Americans over the age of 80 had significant muscle weakness. Not too bad, you might think, but in fact the data show that above the age of 80, less than 50% of thoses studied had normal levels of strength. Combining people the study classified as having weak strength and intermediate strength meant that the percentage of people who had below normal strength rose from 10% of those aged between 60 and 79 to 53% of people past the age of 80. Again, you might think "well what of it? At that age it's not too bad". But we're not talking about the 53% not having "Popeye" muscles, we're talking about people's ability to do things - loss of strength means loss of function. So severe was this loss that many of those classified as having weak muscle strength were unable to sit down into, or get up from, a chair unaided. Compare that with Chris Bonington at 80, Sid Isaacs at 85 or 'Paulus' Laurencin at 82 and see how life's potential is greatly reduced with this loss of strength.

 

Those of a positive turn of mind are fond of saying that age is just a number. At SGSC we take that as a way of expressing the idea that the changes in one's body that typically accompany the passing years are not unalterably linked to the passing of those years. Other people might say "You get old, you get weak, it happens". We say "No, not necessarily - it's a choice". We believe that accepting or not accepting this loss of strength is a decision, it really is in your hands - and, of course, your feet, your legs, your back, your heart, your lungs .....