posted by Mosaic Data Science
Fitness trainers have long since debated the virtues of volume versus intensity. Should I do 50 pushups or a dozen bench presses? Now a new data analysis study of 58,000 heart stress tests suggests that when it comes to survivability, high stress exercise may be more important than high-repetitions. That may come as a surprise to those who like to take long walks.
The first lesson healthcare researchers learn is to expect the unexpected. Any new data set usually has a few surprises and so it is important to impose a minimum of structure while analyzing the data. It is important to let the data speak for itself. In this study, demographic, clinical, exercise, and mortality data were collected for 58,020 participants from the Detroit, Michigan area. Participants were almost evenly split between male and female and the median age was 53 years. The data run from 1991-2009 with a 10-year median span for each participant.
The researchers used Cox proportional hazards models to predict 10-year survival likelihood as a function of the other covariates. No distinctions were made based on the health status of survivors, and the models did not account for the cause of death of the non survivors.
Not surprisingly age and gender were the most predictive covariates. Younger participants and female participants have a longer life expectancy. After that, the two remaining significant covariates were (i) the ability to tolerate physical exertion and (ii) the peak heart rate. For both variables, the higher the better. In other words, survivability is positively correlated with higher physical exertion levels and higher peak heart rates.
These results do not necessarily mean that higher intensity exercise leads to higher survivability. But this new predictive model does tell us that the ability to exercise at higher intensity is a sign of higher survivability. And that ability does not just occur at random. You need to exercise at high intensity levels to be able to achieve high intensity levels. So much for those long walks.