Exercise Resistance, it’s more than a feeling

Are you a paramedic or EMT who saves their workouts for their days off or after shift? You could be significantly reducing the impact of those workouts.

“Exercise resistance” is not just a feeling you get when you’re looking out the window at a cold, rainy day. It’s a term scientists use to refer to a phenomenon characterized by a reduced physiological response to exercise.

If you’re like me, you expect that when you go out for a jog on a day off work you’re going to increase your metabolism and burn off a few calories.

But, curiously, not everyone will experience the same benefits from that workout.

One major factor that recent research indicates carries a high impact on the benefits of exercise (namely, fat oxidation and reduction of plasma triglycerides) is the activity levels on the days preceding the exercise.

In 2016 researchers Kim and colleagues found that exercise resistance was found in as little as 2 days of sedentary life. After 4 days of sedentary living there was almost no response to a single one hour bout of exercise.

The research is part of an expanding body of literature showing that the negative metabolic effects of sedentary life and the positive metabolic effects of physical activity do not perfectly balance each other out.

More recently, Burton and Coyle set out to explore some more nuance to this.

During the two day intervention phase of their study participants were instructed to remain seated or lying for much of the day. They were divided into 3 groups, LOW (2675 steps), LIMITED (4759 steps) and NORMAL (8481 steps) and asked to limit activity to approximate that amount of steps.

On the evening of day 2 (kind of like an after-day-shift workout), the participants completed a 60 minute jog, and then were fed a high fat meal (like picking up a burger and fries on the way home!).

Long story short (you can read the original research if you like long stories), participants in the LOW and LIMITED step range experienced an elevated area under the curve of increased plasma triglycerides of 22-24% and reduced fat oxidation (16-19%). This is the “exercise resistance” phenomenon at work.

What is the take-away for a paramedic?

I’ve written before about how intentional I need to be to get my steps up beyond the sedentary level at work. Even though we are BUSY and running one call to another, there is just so much sitting or standing around in this job.

Recently I’ve let my on-shift exercise habit slide a bit. Looking back at this last tour of work (which was just as ridiculously busy as usual), my average steps were 5700/day. If it were not for my bike ride to and from work, I would be sitting in that LIMITED activity range.

So, even if you are getting regular exercise, it is important to keep active throughout the day while at work. Measuring steps is probably among the most convenient and applicable ways for a paramedic to do this.

My recommendation: even if you are exercising regularly, for optimal fat metabolism it looks like it may be beneficial to target a daily step count of 8500 or higher.