Rest Days for Marathoners: Feel the Fear, and Take Them Anyway

Rest days scare many marathoners. But, they can be good for your physiology. And, a regular, weekly schedule of rest days can be good for your mind.

First, I’ll discuss three groups of marathoners and why they shy away from rest days. Next, I’ll show you how rest days can be good for your immune system, your bones, and your muscles. And, I’ll close with how rest days can be good for you mentally and why you should take them on a regular schedule.

Rest days scare many marathoners

I have met marathoners who insist on running every day. How new they are to the sport tends to match their argument for avoiding rest days.

1. They are new to the sport. Marathoning is their new passion, and they have an all-or-nothing approach to training.
2. They have completed a few marathons. They believe that they’ve mastered the sport. They have heard about the importance of cross-training. But, they have confused cross-training with more training, as in more running days.
3. They are veteran marathoners. They feel as if they have peaked after years of marathons, so they replace rest days with more training.

Rest days scare all three groups. It’s as if there’s no wisdom in taking even one weekly day of rest, as told about God in Genesis.

I attended a speech by Dr. Susan Jeffers soon after she released Feel the Fear and Do It Anyway. I love that book title. When I manage to live by it, good things almost always happen.

So, I have a challenge for you. If you have any fear of rest days, then keep reading. I’ll show you why you should take them anyway!

Rest days are good for your immune system

As a subtype of white blood cells, lymphocytes play a major role in the immune systems of humans. “Lymphocyte subset response” refers to a response by the body to immunological challenges.

Researchers in 2014 published a paper about this response. They had twelve healthy, college-age adults perform an “intermittent run exercise” to exhaustion. Each participant completed this exercise or protocol for three consecutive days.

The researchers’ conclusion?

“Given these lymphocyte responses, it is recommended that a rest day be incorporated following two consecutive days of a high-intensity intermittent run program to minimize immune[-]cell modulations and reduce potential susceptibility.”

What’s surprising is that the intermittent-run protocol entailed only two 30-second intervals:

1. 30 seconds running at maximal speed;
2. 30 seconds running at half of maximal speed.

Granted, marathon training involves runs at speeds between these two. But, marathon training runs are usually much longer. So, it should be smart to conclude that …
[Tweet “A rest day after two marathon training days can be good for your immune system.”]
If you’re still not convinced, look at research from Taipei Veterans General Hospital. Twelve healthy volunteers completed three consecutive days of treadmill runs. Each volunteer ran on each of the three days for 30 minutes at 85% of VO₂ max.

These Taipei researchers concluded that …

“These results support the immunosuppressive effects of excessive exercise ….”

… where “excessive exercise” refers to three consecutive days of 30-minute runs at 85% of VO₂ max.

To many marathoners, though, these runs look much like a typical part of their training! In other words, …
[Tweet “Three straight days of 30-minute training runs can suppress your immune system.”]

Rest days are good for your bones

Most people don’t think about it, but our mature bones are in a lifelong process of remodeling. Also known as bone metabolism or bone turnover, this comprises two competing processes:

1. bone resorption, which removes bone from the skeleton;
2. bone formation, in which new bone gets formed.

As Canadian researchers noted in the introduction to their 2017 article,

“… examination of serum markers of bone turnover has shown an unbalanced increase in bone resorption over bone formation during high[-]volume training. However, the molecular events that precede these changes in bone turnover remain unclear.”

Curious about those molecular events, they looked at two proteins in the blood.

• Osteoprotegerin is a protein that acts to increase bone volume. Osteoprotegerin, also known as OPG, does this by inhibiting bone resorption.
• Sclerostin, also known as SOST, is a protein that inhibits bone formation.

This means that OPG and SOST are serum markers of bone turnover, where:

• OPG inhibits bone resorption;
• SOST inhibits bone formation.

So, the Canadian researchers looked at OPG and SOST in Olympic female rowers. In particular, they looked at OPG and SOST as serum markers of bone turnover across a training season.

For example, consider the serum OPG levels across the rowers at these two time points:

• after one month of 730 minutes/week of training (what they called “T2”);
• after two months of 1200 minutes/week of training (what they called “T6”).

The researchers found a statistically significant 28.7% drop in mean serum OPG levels. Lower OPG levels means less inhibition of bone resorption. And, less inhibition of bone resorption implies a greater risk of bone loss.

In contrast, SOST concentrations increased as the intensity of training increased. Higher SOST levels means more inhibition of bone formation. And, more inhibition of bone formation implies a greater risk of bone loss.

You may have heard or read, as I have, that exercise is good for one’s bones. Many cite weight-bearing exercises, such as running, as a way to strengthen your bones. Physicians and others often quantify bone strength through bone mineral density (BMD).

The Canadian researchers saw no change in BMD, no matter the training intensity. But, as they found, bone density does not tell the whole story.

Granted, the Canadian researchers looked at female rowers, not male and female marathoners. But, these results together imply for marathoners that …
[Tweet “High-intensity training with little rest can cause bone loss without affecting bone density.”]

Rest days are good for your muscles

Vicky Lowry wrote an excellent article about muscles and rest for The New York Times. “Work Out Now, Ache Later: How Your Muscles Pay You Back” has these takeaways for marathoners:

• Delayed onset muscle soreness (DOMS) is the name for soreness that you feel a day or more after a run.
• Contrary to what some thought, DOMS is not due to exercise-induced lactic-acid build-up.
• Instead, DOMS seems to come from exercise-induced microscopic tears in muscles.
• These tears produce inflammation.
• The inflammation manifests itself as pain some 24 to 36 hours after exercise.
• A muscle that repairs the tears becomes better at handling the same exercise later.
• This does not mean that you get stronger right away.
• This does mean, though, that you are less likely to get the same tears in future similar workouts.

This begs the question:
[Tweet “How long does it take a muscle to repair exercise-induced microscopic tears?”]
The American College of Sports Medicine’s then-president gave the answer in Lowry’s article:

“… delayed muscle soreness … fades after a day or two of rest [emphasis added].”

Rest days are good for your mind

Rest days may help you in other physiological ways beyond those covered here. But, rest days can help you in another way beyond the physiological benefits.
[Tweet “No matter how a marathon training run went, a rest day can help you mentally.”]

• If the run went well, then the pause to ponder it can rejuvenate your enthusiasm for training.
• If the run did not go well, then you have time to consider how you might change your plans for your next workout.

Without a rest day, you can turn what was fun into mind-numbing repetition. Or, you can reinforce a bad approach and end up getting injured or burning out.

Take rest days every week

There is another mental aspect to rest days.
[Tweet “Taking rest days on a regular weekly schedule trains your mind to expect a work/rest rhythm.”]
Why does this matter? Your unconscious mind is always looking for ways to protect you. Weekly rhythms reduce what you might call the psychic load on your unconscious mind.

If you want to learn more about rest days as well as the unconscious mind, then I have a recommendation. Check out Mental Tricks for Endurance Runners and Walkers. It includes other mental tricks to use in training. And, it even includes mental tricks to use during or after a marathon.

Interested? Click here:

Image Credit: Pixabay