Cardio and Weights Can Mix!
Many people trying to build muscle believe they shouldn’t do cardio on the same day because it detracts from their recovery ability. At the same time, those who do more cardio like to use the weights on days when they are not doing cardio. This feels right to people who work out, but is it true? Two recent studies suggest that is not.
Researchers at McMaster University in Canada studied middle-aged men who did not work out regularly. These subjects went through three different routines. One was riding a stationary bike for forty minutes. Another day that same group did eight hard sets of leg extensions. On yet another day, the group both rode the bike for half as long and then did half the number of sets of leg extensions. In the final workout on a different day, the group did both the lower time on the bike and the lower number of leg extensions, but did the leg extensions first. The researchers took biopsies of the subjects’ leg muscles, this time both before and after each exercise session.
The researchers hypothesized that that the cardio training would affect the portion of the cells involved in the production of energy and that the resistance training would affect the protein synthesis in the muscles. Since each of these cell processes affects the other, the researchers expected that doing both kinds of training on the same day would interfere with progress from each of the kinds. However, no difference in the cell activity or other interference was found. This study was published in the April 5, 2012 edition of The Journal of Applied Physiology.
In a Swedish study at The Karolinska Institute, young men who had been exercising regularly pedaled an exercise bike for forty-five minutes with just one leg. Later in the day, they did leg extensions with both legs. Thus, each subject used one leg for cardio only and the other for both cardio and weight training. The researchers then compared biopsies of the leg muscles used both before and after the exercises.
You Can Lift and Run on the Same Day!
The results of the Swedish study were similar to those of the Canadians. In the March 28 issue of Medicine & Science in Sports & Exercise, the Swedish researchers concluded that their subjects showed no substantial difference in the molecular responses when the subjects performed both cardio and weight training or cardio alone. Specifically, doing cardio before weights does not hinder muscle building.
These conclusions are useful for planning your workouts for convenience, instead of for theory. However, they do suggest that doing more work may not result in greater results. Left unexplored in these studies is whether there are other physiological stores that may be affected by working out more frequently or less frequently. It does seem like there is a point after which exercise on a given day becomes unproductive.
By Robert Braun