You’ve just completed a hard exercise class or gone on a long, undulating hike fraught with hazards and hills.
Or maybe you’ve taken on a do-it-yourselfer renovation project, but it turned out to be a don’t-it-yourselfer. You wind up exhausted and out of breath looking forward to resting the next day or two.
But what you find is that as tired as you were initially, you end up being much stiffer and sore the two days following the hard physical effort than the day you exercised. Why is that and what is actually sore?
We’ve all experienced this physical sensation at one time or another known as Delayed Onset Muscle Soreness, or DOMS for short. DOMS is experienced under a few specific conditions.
It is often experienced when we do exercise that is much harder than we’re used to or uses muscles in a different way than we’re accustomed to.
For instance, a runner who one day does a high intensity exercise class that involves lots of squats and lunges will be moving their hip and knees into deeper ranges of motion and loading them with more resistance (especially if they use weights) than they’re used to.
Another factor that produces DOMS is what’s called ‘eccentric’ muscle contractions – this is the lowering phase of a weight lifting movement. Taking a heavy box from a table and lowering it to the floor is an example. Another example is the landing phase of a jump or absorbing energy as you run downhill.
In fact, in laboratory tests done between groups of people who only lift a heavy weight, say from the floor to standing position (called ‘concentric’ muscle contraction) and another group who only lowers the weight from standing down to the floor (‘eccentric’), it is the group that lowers the weight that experiences DOMS.
In the past, it was thought that DOMS was caused by lactic acid build-up in the muscles, but this has been shown not to be the case since lactic acid gets used up as fuel and removed from your muscles very soon after exercise stops.
It is not present in the 24 to 48 hours when DOMS peaks. The prevailing theory since lactic acid was discounted was that damage to the muscle was the source inflammation and pain. But it turns out the recent research has shown that to be false, as well.
Although it feels like it’s the muscle that is sore, recent research studies have shown that the source of DOMS is not the muscle but the fascia (pronounced ‘fash-a’).
Fascia is the connective tissue or sheath that covers bundles of muscles. It spreads throughout the body providing a connective tissue network linking muscle groups and other tissue, vessel and nerve systems. The results of the DOMS studies showed that soreness was localized to the fascia and not the muscles. Why is this? Researchers are not sure of the mechanism at this point, but some theories have been proposed.
One theory is that muscles and fascia have different elastic properties, causing a zone of shear where fascia is subjected to micro-damage and possibly adhesions, and this is the cause for DOMS.
So what can you do to ease DOMS? Doing low to moderate cardiovascular exercise will help, but this can even be hard sometimes when fatigue is great.
Stretching can drastically reduce DOMS possibly because stretching causes the fascia to slide more smoothly past neighboring tissue.
Over time, if you allow adhesions between fascial layers to accumulate, this can potentially cause decreased mobility, increasing stiffness and an ongoing source for soreness.
Kerry Senchyna holds a bachelor of science degree in kinesiology and is owner of West Coast Kinesiology.
