Wow! The extensive molecular changes that occur during and after working out underscore how consequential activity is for our bodies and health.
When we exercise, the levels of thousands of substances in our bloodstream rise and drop, according to an eye-opening new study of the immediate, interior impacts of working out.
The study is the most comprehensive cataloging to date of the molecular changes that occur during and after exercise and underscores how consequential activity — and inactivity — may be for our bodies and health.
scientists… have zeroed in on various sets of molecules in our bloodstreams associated with different aspects of our biology. This research generally is known as “omics” science.
Metabolomics, for instance, enumerates and analyzes molecules in our blood that influence metabolism — everything from appetite hormones to enzymes excreted by gut microbes.
Genomics maps the molecules involved in gene expression; proteomics ditto for proteins; lipidomics for fat-related molecules; and so on.
scientists at Stanford University and other institutions decided to try to complete a full census of almost every molecule that changes when we work out.
group of about 100 adult men and women… 36 of them, representing an age range between 40 and 75 and a full spectrum of fitness and metabolic health.
Some were in good aerobic condition, others out of shape, and some displayed fine blood-sugar control, while others were insulin resistant.
The researchers drew blood from each volunteer and then asked them to complete a standard treadmill endurance test, running at an increasing intensity until exhaustion, usually after about nine or 10 minutes of exercise.
The researchers drew more bloodimmediately after this exertion and again 15, 30 and 60 minutes later. Later, they also drew blood from some of the volunteers before and after they had quietly rested, as a control measure.
They looked for molecules that were known to change when people exercise, but also for any that might not have been examined in previous exercise studies but were showing up in people’s blood now.
They wound up measuring the levels of 17,662 different molecules.
Of these, 9,815 — or more than half — changed after exercise, compared to their levels before the workout.
The types of molecules also ranged widely, with some involved in fueling and metabolism, others in immune response, tissue repair or appetite. And within those categories, molecular levels coursed and changed during the hour.
Molecules likely to increase inflammation surged early, then dropped, for instance, replaced by others likely to help reduce inflammation.
Here we see the body’s amazing ability to make constant adjustments to keep us functional. Maintaining a steady biological state (homeostasis) requires a delicate balancing of different hormones and other chemicals.
Interestingly, though, different people’s blood followed different orchestrations. Those who showed signs of insulin resistance, a driver of diabetes, for instance, tended to show smaller increases in some of the molecules related to healthy blood sugar control and higher increases in molecules involved in inflammation, suggesting that they were somewhat resistant to the general, beneficial effects of exercise.
The levels of other molecules ranged considerably in people, depending on their current aerobic fitness.
“I had thought, it’s only about nine minutes of exercise, how much is going to change? A lot, as it turns out.”
This study was small, though, and looked at a single session of aerobic exercise, so cannot tell us anything about the longer-term molecular effects of continued training or of how, precisely, changes in molecular levels subsequently alter health.
I’d like them to find the molecule that makes us desire exercise, an urge that lifts us up of the couch and drives us into activity, a passion for excessive movement, an endless capacity to tolerate the pain…