{"id":31305,"date":"2019-08-15T21:37:37","date_gmt":"2019-08-15T21:37:37","guid":{"rendered":"https:\/\/solvecfs.org\/?p=31305"},"modified":"2022-01-11T02:55:07","modified_gmt":"2022-01-11T02:55:07","slug":"using-a-heart-rate-monitor-to-prevent-post-exertional-malaise-in-me-cfs","status":"publish","type":"post","link":"https:\/\/solvecfs.org\/using-a-heart-rate-monitor-to-prevent-post-exertional-malaise-in-me-cfs\/","title":{"rendered":"Using a Heart Rate Monitor to Prevent Post-Exertional Malaise in ME\/CFS"},"content":{"rendered":"\t\t
\n\t\t\t\t\t\t\t\t\t
\n\t\t\t\t\t\t
\n\t\t\t\t\t
\n\t\t\t
\n\t\t\t\t\t\t\t\t
\n\t\t\t\t
\n\t\t\t\t\t\t\t

From ProHealth.com: Using A Heart Rate Monitor to Prevent Post-Exertional Malaise in ME\/CFS By Suzan Jackson<\/h4>

This article was first published on\u00a0ProHealth.com<\/a>\u00a0and is reprinted here with permission of ProHealth and the author Suzan Jackson.<\/em><\/p>

\"\"<\/p>

One of the identifying characteristics and key symptoms of ME\/CFS (myalgic encephalomyelitis \/ chronic fatigue syndrome) is an intolerance to even mild exertion, known as Post-Exertional Malaise or PEM. In simple terms, this means that when people with ME\/CFS engage in activity \u2013 even just walking to the bathroom or making a simple meal \u2013 they experience a sudden worsening of all\u00a0chronic fatigue syndrome symptoms<\/a>\u00a0(usually hours or days after the exertion), often aptly called a \u201ccrash\u201d by patients. Fortunately, there are ways to quantify your limits and use a heart rate monitor to stay within those limits, thus greatly reducing post-exertional crashes.<\/p>

What Exactly is Post-Exertional Malaise (PEM)?<\/b><\/h2>

In a study conducted by well-respected ME\/CFS researcher Leonard Jason, more than 1500 adult patients from over 35 countries diagnosed with myalgic encephalomyelitis or chronic fatigue syndrome used a self-reported questionnaire to describe their experiences of PEM. Seventy-eight percent of respondents said that PEM occurred as the result of \u201cbasic activities of living,\u201d which makes it very difficult to avoid. Patients reported that their PEM symptoms lasted anywhere from one day to six months. Most patients in the study reported limited success with pacing (staying within your exertion limits), but only about 10% of those patients used a heart rate monitor to quantify their limits.<\/p>

<\/a>So, what\u2019s happening behind the scenes to cause PEM? One underlying issue is that the cells of people with ME\/CFS don\u2019t process oxygen properly. In a healthy person (even one who is out of shape), exertion results in aerobic exercise, where the cells use oxygen to produce energy. Past a certain point, known as the Anaerobic Threshold or AT, the cells run out of adequate oxygen and switch to using glucose to create energy. During anaerobic metabolism, lactic acid, lactate, and carbon dioxide all increase in the cells and endurance is reduced. An elite athlete might switch to anaerobic exercise after running for many miles, indicating a very high AT, while those with heart disease typically have a lower-than-normal AT. For healthy people, AT is usually estimated simply by (220 \u2013 age), which is the heart rate at which they switch from aerobic to anaerobic metabolism.<\/p>

For someone with ME\/CFS, though, the AT is much lower, often just 50-60% that of a healthy person. This means that with minimal exertion, we switch from aerobic exercise to anaerobic exercise because there isn\u2019t enough oxygen available to our cells, thereby relying on energy reserves we just don\u2019t have. This is why a short walk for us can cause a similar (or worse) reaction as an athlete running a marathon!<\/p>

To makes matters worse, more than 97% of patients with myalgic encephalomyelitis or chronic fatigue syndrome have some form of\u00a0Orthostatic Intolerance<\/a>\u00a0(OI), which is an inability to hold heart rate and\/or blood pressure steady while upright. For those with one type of OI, Postural Orthostatic Tachycardia Syndrome (POTS), heart rate jumps up considerably when standing or even just sitting up. This means that they will hit that reduced AT even faster.<\/p>

How Do I Find Out What My Anaerobic Threshold (AT) Is?<\/b><\/h2>

The gold standard for measuring AT is to use gas exchange methods during exercise testing. Heart rate and blood pressure are measured during exertion, but the equipment also precisely measures how much oxygen is taken in and how much carbon dioxide is expelled. For those with ME\/CFS, Workwell Foundation (formerly Pacific Fatigue Lab) developed 2-day Cardiopulmonary Exercise Testing (CPET) that measures AT and also shows clearly that PEM results after exertion, further dropping AT on the second day. This is the most accurate way to measure your AT (and also the best test to use in a disability case because it provides evidence of PEM).<\/p>

Not all ME\/CFS patients can afford or manage a 2-day exercise test, though. This is where a heart rate monitor (HRM) becomes useful. You can begin with an estimate of your AT using a modified formula and then use your HRM and observations to test whether it should be adjusted up or down. Since most people with ME\/CFS have an AT that is usually 50-60% of healthy people, use this formula to estimate your own AT:<\/p>

(220 \u2013 age) * 0.6 = estimated AT
(If you are more severely ill, use 50% or 0.5 instead of 0.6)<\/p>

Alternatively, women can try:<\/p>

(220 \u2013 (age * .88)) * 0.6 = estimated AT
(Or if severely ill, use 0.5 instead of 0.6)<\/p>

Use the HRM to test how accurate your estimated AT is. Do you still crash when staying below it? Then adjust AT downward, until you find the point where you can prevent PEM by staying below your AT. Or, if you stay below your AT and never crash from over-exertion, you can carefully experiment with going higher than your estimated AT by a few beats per minute (bpm). Experience will help to fine-tune your estimated AT.<\/p>

How Do I Use a Heart Rate Monitor to Prevent PEM?<\/b><\/h2>

Now that you have an estimate of your AT, the heart rate monitor can help you stay below that limit, thereby preventing post-exertional malaise. There are many choices available now for heart rate monitors, from those that only measure heart rate to wearable devices like Fitbits and smart watches that have other uses. Look for these features:<\/p>