First, thank you for a very important and well-written article [BCMJ 2016;58:203-209].I took a look at the four recent studies that were discussed in the “How much exercise is enough?” section and wonder if you can shed light on something. The clearest U-curve is found in the study on Copenhagen joggers.[1,2] The study on runners in Texas also showed a U curve though it was less striking. The study on all forms of exercise in Taiwan, however, showed a continued benefit with longer and more vigorous exercise.
The main differences in these studies that I found were:
- Difference in race: East Asian versus two white populations.
- Difference in exercise modality: running versus all forms.
- Difference in follow-up period: The study in Taiwan was only 8 years of follow-up, which is less than in Copenhagen or Texas, though the subgroup analysis in Copenhagen was also around this length and showed a marked U-curve.
I didn’t see any obvious differences in other subject characteristics, though I may have missed something.
Are there any other studies suggesting differences in exercise benefits among different races or exercise modalities?
Thanks again for a stimulating article!
—Joel Fox, MD (PGY-1 Psychiatry)