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Stress is stress. Our bodies don’t necessarily know the difference between where stressors originate. A hard training session, a fight with a partner, looming economic concern, uncertainty of the ongoing pandemic; each contributes to the stress response with multiple sources piling up leading to larger problems in mind and in body. For runners, this can become increasingly problematic on a number of levels, including impacting the ever important relationship between training, stress and recovery.
What is the Vagus Nerve?
Enter the Vagus Nerve. This 10th cranial nerve is the longest and most complex nerve in the body. It connects our heart, lungs, GI system and other major organs to our brain as it wanders all the way down into our lower abdomen. In fact, it gets its name from the Latin etymology for Vagus translating to “wandering.” Perhaps most importantly, the Vagus Nerve is an important toggle between the sympathetic and parasympathetic branches of our nervous system; the former flooding our bodies with stress hormones signaling threat (whether real or imagined) and triggering the “fight or flight” response, the latter tapping into our bodies ability to “rest and digest.” One of the primary features of the vagus nerve is to help regulate heart rate and heart rate variability.
Now, this may seem like an advanced anatomy and physiology lesson with information about the nervous system suggesting that these responses may be largely outside our control. But quite the contrary. We can actively impact our vagus nerve and parasympathetic nervous system through specific practice. The overall health and quality of our vagus response is most commonly referred to as Vagal Tone, which we can measure through a relatively straightforward biofeedback process examining Heart Rate Variability (HRV).
Heart Rate Variability
HRV is a measurement that emerges from understanding the nuanced interplay between the fight or flight (sympathetic) and rest and digest (parasympathetic) branches of our nervous system. We want our HRV readings to be high. High HRV is a signal of a body that is highly responsive and adaptive in a balanced way. For athletes, high HRV typically signals balanced training with recovery. Low readings typically suggest prolonged exposure to stress or persistent medical concerns and typically are accompanied by feelings of fatigue or exhaustion. For an athlete, low readings indicate the likelihood of over-training with inadequate recovery.
Biofeedback programs measuring HRV are now widely available, even for the public. You don’t need an advanced degree to obtain one or advanced training to understand the basics of how they work. And many watches promote the capability of measuring HRV, including many Garmin products with a chest strap heart rate monitor, WHOOP (specifically designed to examine sleep and recovery metrics), and Apple watches. But a word of precaution, research indicates that heart rate chest straps far outperform optical heart rate sensors when measuring heart rate, especially as exercise intensifies. Less research exists on the accuracy of wearable technology with HRV, with a 2018 study indicating that the performance of such devices, “ranged from very good to excellent during rest, yet it declined progressively as exercise level increased” with a call for more research into the matter. So take any HRV readings from wearable technology as a rough estimate, with some devices performing better than others.
Exercises to Train Vagal Tone
You don’t necessarily need any technology to train HRV, however. We can train vagal tone through simple, yet effective breathing and/or meditation practices allowing our body and intuition to guide us. When I’m using biofeedback to train athletes on HRV in my office, one of the first practices I have them do is a basic 5-5 breathing exercise. Simply stated, you breathe in slowly and steadily for a count of 5, then exhale slowly and steadily for a count of 5. In essence, what we’re aiming for is to slow breathing down to 6 breaths in 1 minute (most adults typically take between 10 – 16 breaths per minute, so this is a sizable slow down). Deep rhythmic breathing in this manner, even for just a few minutes, shows a marked change in HRV readings, including physiological shifts engaging the parasympathetic branch of the nervous system helping your body enter a natural state of recovery.
Another simple, yet effective, strategy for training vagal tone is merely to extend the exhale and make it longer than the inhale. This doesn’t necessarily need to be timed, your subjective sense of your own breath will work just fine. These practices are best utilized in a deliberate manner 3 times throughout the day to ensure you are activating the recovery branch of your nervous system and slowing down the accumulation of stress. I recommend aiming for a 3-5 minute widow once in the morning, once in the afternoon, and once in the evening. As a runner, you don’t need to attempt to breathe in this manner during your runs. Rather, utilize these practices prior to working out to get your mind and body aligned and post-run to aid in the recovery process.
Why it Matters
You may be wondering why as an athlete this matters to your performance or your recovery. Training the vagus nerve and our parasympathetic response is important for runners for a number of reasons, including research that blends together both performance improvements and prescribing when to tackle harder workouts. Research involving HRV training has shown that it leads to increased power output for cyclists, and has demonstrated the success of using HRV as a guide for determining training zones when prescribing workload in runners. Further research indicates that recreational runners with a higher level of baseline HRV improved performance over a 14 week intense training period compared to those with a lower baseline HRV. This particular research is compelling for any runner considering embarking on a training plan with a particular goal in mind. And there’s copious amounts of research that connects healthy HRV with a variety of general health and wellness improvements, from reduction in inflammation to subjective feelings of calm and focus. Not bad when you consider it only takes deliberately slowing your breathing several times per day.
All of this comes back to a really simple concept that we’ve all heard our entire lives when we are feeling stressed, anxious or overwhelmed: “Just Breathe.” We may intuitively know that this helps, but consider how many of your daily breaths you are either aware of or are actively engaging. My guess is that most are done without deliberate attention. Optimal performance and optimal recovery require regulated states of arousal, which we can actively influence through this process. You are likely to find a subjective sense of calm, focus and reduced anxiety/tension through these practices. And the added potential benefits of improved performance and recovery aren’t too bad either.
Dr. Justin Ross is a clinical psychologist in Denver, CO, specializing in human performance. He is an 11 time marathoner, with 6 BQs and a personal best of 2:57. His newly launched course, Unlock Your Athletic Potential is a masterclass aimed at building fundamental psychological skills for sport.