You Don’t Have to Kill Yourself to Be Well

“Everything in excess is opposed to nature.”
—Hippocrates of Kos

People say things like:

“Don’t kill yourself trying to get it done tonight. It’s not due until next week.”

“Will you please look for Maria’s onboarding documents? Don’t kill yourself. If you can’t find them, I’ll request another set from human resources.”

“Don’t kill yourself to get here exactly at 10. If you’re a little late, it’s no big deal.”

The implication is there are times when it’s important to “kill yourself” to get something done.

Interesting, right?

Except for war, and maybe work, exercise is the activity in which killing yourself in the name of good is most socially endorsed:

“Boot camp was good. Alexa nearly killed us, but it was an awesome workout.”

“I had a great run. I almost died at mile 9 though.”

“Sometimes it feels like my fitness trainer is trying to kill me, but he tries to keep things fun too.”

Because most people exercise to improve their well-being, it’s ironic that death language is so common when people talk about exercise.

This isn’t just semantics. It’s a firmly held belief by many people that exercise has to suck in order to be beneficial. This belief is encapsulated in the common saying, “No pain, no gain.” This belief drives many people to exercise harder, longer, and more. More like more, more, more!

But is more better?

More Isn’t Better

The mistaken belief that more is better is killing people.

The mistaken belief that more is better keeps a lot of people on the couch. They figure they need to do a lot of exercise to see any benefit and going from none to a lot feels understandably daunting. Being sedentary is deadly. Beliefs that keep people sedentary are killing people.

The mistaken belief that more is better drives some people to exercise like crazy. This kills people in another way. Excessive exercise is also deadly. As deadly as being sedentary.

What?

It’s true, even though most people consider exercise all good, it’s actually only good to a point.

Even though it’s rarely discussed, it’s well-established that excessive exercise is dangerous. (1)

In fact, it’s well-established that excessive exercise is as dangerous as being sedentary. (1)

The benefits of exercise are best demonstrated with a U-shaped curve, an upside-down U in this case. That is, both low and high exercise loads are correlated with low wellness benefits and moderate exercise loads are correlated with high wellness benefits. (1)

To drive this point home, let’s talk about it in terms of sickness, the opposite of wellness. In this case, think about a U-shaped curve, with the U right side up. Both low and high exercise loads are correlated with high sickness rates and moderate exercise loads are correlated with low sickness rates. (1)

Sadly, very few people talk about this. Many are simply ignorant of these facts. Many benefit from promoting excessive exercise.

Let’s dig in.

Immunity

It’s well-established that exercise boosts immunity, but what happens when exercise loads creep up?

Two systematic reviews sum up the scientific evidence from dozens of randomized, controlled studies aimed at answering this very question:

“Many physiological systems are affected by the process of overtraining and the OTS; but one system in particular, the immune, is highly susceptible to degradation resulting in a reduction in overall health and performance.” (2)

“In conclusion, numerous studies have shown an inverse relationship between exercise workloads and function of the immune system.” (3)

Compromise immunity and you compromise wellness.

Cardiovascular Disease

What’s the relationship between exercise load and cardiovascular disease?

Endurance athletes have the healthiest hearts around because they exercise so much, right?

Not exactly.

From the European Heart Journal:

“This study demonstrates, for the first time, an association between endurance exercise of increasing duration and structural, functional, and biochemical markers of cardiac dysfunction in highly trained athletes.” (4)

From the Journal of the American College of Cardiology”

“Long-term strenuous endurance exercise may induce pathological structural remodeling of the heart and large arteries. Emerging data suggest that long-term training for and competing in extreme endurance events such as marathons, ultra-marathons, ironman distance triathlons, and very long distance bicycle races can cause transient acute volume overload of the atria and right ventricle, with transient reductions in right ventricular ejection fraction and elevation of cardiac biomarker levels. Months to years of repetitive injury in some people may lead to patchy myocardial fibrosis, particularly in the atria, interventricular septum, and right ventricle, creating a substrate for atrial and ventricular arrhythmias. Additionally, long-term excessive exercise may be associated with coronary artery calcification, diastolic dysfunction, and large artery wall stiffening.” (5)

From the medical journal Mayo Clinic Proceedings:

“Chronic excessive sustained exercise may also be associated with coronary artery calcification, diastolic dysfunction, and large-artery wall stiffening.” (6)

No bueno.

“Mental Health”

What’s the relationship between exercise load and “mental health”?

A large observational study explored this question in depth.

What did the researchers find?

First, they found, as many other researchers have, that exercise boosts “mental health”:

“This study shows a meaningful association between exercise and mental health, in the largest cross-sectional sample to date, even after adjusting for several sociodemographic and physical health characteristics that themselves are known to contribute to mental health burden. Individuals who exercised had about 1.5 (about 43%) fewer days of poor mental health in the past month than individuals wo did not exercise, but were otherwise similar in terms of age, race, gender, marital status, income, employment status, education level, BMI [body-mass index] category, self-reported physical health, and previous diagnosis of depression.” (7)

Second, when exercise load was considered, they ran right into the U-shaped curve:

“We observed U-shaped relationships between exercise frequency and mental health burden, whereby individuals who exercise between three and five times a week had lower mental health burden than those who exercised fewer than three or more than five times.”

“More exercise was not always associated with better mental health, and we found evidence for optimal ranges of duration (45 min) and frequency (between three and five times per week).”

“This pattern of optimal duration was broadly consistent across many exercise types. In general, small reductions were seen for individuals who exercise longer than 90 min, and durations of more than 3 h were associated with worse mental health burden than exercising for either 45 min [minutes] or not exercising at all.” (7)

For emphasis:

1. Subjects who received the most “mental health” benefits exercised between three and five times a week for about 45 minutes each time.
2. Subjects who exercised the most had worse “mental health” than those who didn’t exercise at all. (7)

Mortality

What’s the ultimate measure of wellness?

Living.

In epidemiology, its called “mortality”, and the relationship between exercise load and mortality is very interesting.

From the Journal of the American College of Cardiology:

“In this prospective, observational study, which included 1,098 healthy joggers between 20 and 86 years of age who were followed up for 12 years, we compared the long-term all-cause mortality rates of light, moderate, and strenuous joggers with the long-term mortality rate of sedentary nonjoggers. We found a U-shaped association between jogging and mortality. The lowest mortality was among light joggers in relation to pace, quantity, and frequency of jogging. Moderate joggers had a significantly higher mortality rate compared with light joggers, but it was still lower than that of sedentary nonjoggers, whereas strenuous joggers had a mortality rate that was not statistically different from that of sedentary nonjoggers.”

“Our results, which were obtained by using a large random sample of men and women, showed that although joggers as a group appear to live longer than sedentary nonjoggers, light joggers and moderate joggers have lower mortality rates than sedentary nonjoggers, whereas strenuous joggers have a mortality rate that is not statistically different from that of the sedentary group. The U-shaped association suggests the existence of an upper limit for exercise dosing that is optimal for health benefits.”

“On the basis of current knowledge, if the goal is to decrease the risk of death and improve life expectancy, going for a leisurely jog a few times per week at a moderate pace is a good strategy. Higher doses of running are not only unnecessary but may also erode some of the remarkable longevity benefits conferred by lower doses of running.”

“Compared with more sedentary people, people who jog regularly exhibit a significantly lower all-cause mortality rate. Those who jog lightly or moderately appear to benefit more than strenuous joggers, whose long-term mortality rate is similar to that of sedentary people.” (5)

Exercising excessively is as deadly as being sedentary.

Fertility

We’ve established the relationship between exercise load and living.

What’s the relationship between exercise load and creating new life?

From the medical journal Reproductive Biology and Endocrinology:

Ladies first:

“Physical activity has been shown to confer a protective effect on fertility when coupled with weight loss in obese women. However, excessive exercise can negatively alter energy balance in the body and affect the reproductive system.”

“When energy demand exceeds dietary energy intake, a negative energy balance may occur and may result in hypothalamic dysfunction and alterations in gonadotropin-releasing hormone (GnRH) [a reproductive hormone] pulsality [the variability of blood velocity in a vessel], leading to menstrual abnormalities, particularly among female athletes.”

“Increased frequency, intensity, and duration of exercise were found to be significantly correlated with decreased fertility in women, including an OR [odds ratio] of 3.5 for infertility in women who exercised every day.”

“A study examining 2,232 women undergoing in vitro fertilization (IVF) found that women who engaged in cardiovascular exercise for 4 hours or more per week for as little as one year prior to the treatment had a 40% decrease in live birth rate as well as higher risks of cycle cancellation and implantation failure.”

“Wise, et al. also found a significant dose-response relationship between vigorous activity and time to pregnancy.” (8)

And now for the gentlemen:

“A healthy amount of exercise in men can be beneficial. Physically active men who exercised at least three times a week for one hour typically scored higher in almost all sperm parameters in comparison to men who participated in more frequent and rigorous exercise. Moderately physically active men had significantly better sperm morphology (15.2%), the only ones to be ranked above Kruger’s strict criteria [a measure of sperm function] in comparison to the men who played in a competitive sport (9.7%) or were elite athletes (4.7%).” (8)

In men who exercise the most, sperm function is less than a third as good as it is in men who exercise moderately. (8)

In women, frequency, intensity, and duration of exercise are all correlated with decreased ability to get pregnant. (8)

The notion that more is better fails again.

More Is Worse

When nature has a message for you, it first whispers in your ear, then knocks on your door, and finally burns your home down.

This scientific evidence has a clear message for you:

More is worse.

Any way you look at it, exercise is incredibly good for you.

And there’s clearly a point of diminishing returns.

More isn’t better.

More is dangerous.

More is deadly.

You don’t have to kill yourself to be well.

Killing yourself does, in fact, kill you.

Epilogue: How Much Is Too Much?

From the medical journal Mayo Clinic Proceedings:

“From a population-wide perspective, physical inactivity is a much more prevalent public health problem than excessive exercise. The Physical Activity Guidelines for Americans call for 150 min/wk or more of moderate-intensity aerobic PA or 75 min/wk of vigorous-intensity aerobic PA. A recent survey of a half million adults in the United States reported that about 10 of every 20 people fail to obtain this suggested minimum weekly dose of PA. However, extrapolation of the data from the current Williams and Thompson study to the general population would suggest that approximately 1 of 20 people is overdoing exercise, potentially increasing the risk-to-benefit ratio. Individuals from either end of the exercise spectrum (sedentary people and overexercisers) would probably reap long-term health benefits by changing their PA levels to be in the moderate range.

Exercise is unparalleled for its ability to improve CV health, quality of life, and overall longevity. If the current mantra ‘exercise is medicine’ is embraced, PA might be best analogized as a drug, with indications and contraindications, as well as issues related to underdosing and overdosing. As with any powerful therapy, establishing the safe and effective dose range is fundamentally important—an insufficiently low dose may not bestow full benefits, whereas an overdose may produce dangerous adverse effects that outweigh its benefits. Fortunately, the exercise dose-response range that is safe and effective for improving CV health and longevity is broad. Although there is a concerted, research-based effort to reduce physical inactivity and prolonged periods of sitting, increasing data regarding the other end of the exercise continuum now suggest that it may be possible to have too much of a good thing.

On the basis of multiple studies, it might be prudent to limit chronic vigorous exercise to no more than about 60 min/d.”

“A weekly cumulative dose of vigorous exercise of not more than about 5 hours has been identified in several studies to be the safe upper range for long-term cardiovascular health and life expectancy.” (1)

Author’s note: I put “mental health” in quotes because the physical, emotional, and mental, experiences of life are one and the same. The fact that exercise (something reductionists primarily consider “physical”) improves what reductionists call “mental health” proves this fact.

(1) Exercising for Health and Longevity vs Peak Performance: Different Regimens for Different Goals. Mayo Clinic Proceedings, 2014, 10.1016/j.mayocp.2014.07.007.
(2) The Immune System and Overtraining in Athletes: Clinical Implications. Acta Clinica Croatica, 2012, 10.17615/rp65-1z44.
(3) Does Exercise Increase the Risk of Upper Respiratory Tract Infections? British Medical Bulletin, 2009, 10.1093/bmb/ldp010.
(4) Exercise-Induced Right Ventricular Dysfunction and Structural Remodeling in Endurance Athletes. European Heart Journal, 2012, 1093/eurheartj/ehr397.
(5) Dose of Jogging and Long-Term Mortality. Journal of the American College of Cardiology, 2015, 10.1016/j.jacc.2014.11.023.
(6) Potential Adverse Cardiovascular Effects from Excessive Endurance Exercise. Mayo Clinic Proceedings, 2012, 10.1016/j.mayocp.2012.04.005.
(7) Association Between Physical Exercise and Mental Health in 1.2 Million Individuals in the USA Between 2011 and 2015: A Cross-Sectional Study. The Lancet Psychiatry, 2018, 10.1016/S2215-0366(18)30227-X.
(8) Lifestyle Factors and Reproductive Health: Taking Control of Your Fertility. Reproductive Biology and Endocrinology, 2013, 10.1186/1477-7827-11-66.

About Jason Gootman
Jason Gootman is a Mayo Clinic Certified Wellness Coach and National Board Certified Health and Wellness Coach as well as a certified nutritionist and certified exercise physiologist. Jason helps people reverse and prevent type-2 diabetes, cardiovascular disease, and other ailments with evidence-based approaches to nutrition, exercise, stress reduction, holistic wellness, and, most importantly, lasting behavior improvement and positive habit formation. As part of this work, Jason often helps people lose weight and keep it off, in part by helping them overcome the common challenges of yo-yo dieting and emotional eating. Jason helps people go from knowing what to do and having good intentions to consistently taking great care of themselves in ways that help them add years to their lives and life to their years.