Too much of a good thing? How to tell if you're over-doing this healthy habit.
Few people are ever going to tell you to cut back on exercising, but did you know that over-exercising could actually be bad for your heart health? Contrary to popular belief, over-exercising can lead to some very negative outcomes such as increased resting heart rate, high blood pressure, and even heart attacks.
So how do you know if you're over-exercising? Check out this article to find out.
How over-exercising could actually be bad for your health
We all know that exercise is good for us. It helps to improve our cardiovascular health, strengthens our muscles and bones, and can even help to improve our mood. It has even been shown to help extend our lifespan by slowing down accelerated biological aging![1]
However, there is such a thing as too much of a good thing.
Heart Rate
As early as 1992, researchers discovered that one of the first signs that you might be over-exercising is if you notice that your resting heart rate has increased.[2] Your resting heart rate is the number of times your heart beats per minute when you are at rest. A normal resting heart rate is between 60 and 100 beats per minute.
If you find that your resting heart rate has increased, it could be a sign that you are over-training. When you over-train, your body is not able to recover properly from your workouts. This can increase your resting heart rate as your body tries to compensate for the extra stress you are putting on it.
In one study, runners who overtrained had a resting heart rate that was 10 beats per minute higher on average than their healthy controls.[3]
Blood Pressure
Another sign that you might be over-exercising is if you develop high blood pressure. When you exercise, your heart rate increases, increasing the rate at which blood flows through the vessels. This is a normal response and is what helps to improve your cardiovascular fitness.
However, if you are over-training, this process can become chronic and can lead to high blood pressure. This was noticed by researchers as early as 2004 with a publication through John Hopkins Medicine showing those who over-train had higher resting blood pressures.[4]
If you notice that your blood pressure has increased, it is important to see your care provider.
Heart Rate Variability
This marker allows healthcare teams to understand how responsive your heart rate is in response to a stimulus. Think of your car, it wouldn't be very practical if your vehicle only travelled between 50 and 60 km/h (31 - 37 mph). A vehicle that has a broad range of speeds from zero to 120 km/h (75 mph) is far more useful. This is heart rate variability - a healthy heart can range from a relaxed 60 beats per minute to upwards of 180 beats per minute during intense exercise.
Over-training is responsible for a strong link between stressed-out athletes and decreased heart rate variability.[5]
Heart Attack
Finally, a heart attack is one of the most serious consequences of over-training.
A study published in 2017 tracked 3,200 people for 25 years, from their time as young adults. What they discovered is those who exercised more than three times the recommended amount of 150 minutes per week (30 minutes/day) were at risk of coronary artery calcification (CAC) - 27% higher in fact! CAC occurs when calcium plaques form in the arteries, a warning sign and predictor of future heart disease.[6]
It isn't just cardiovascular changes though, and exercising more than is healthy can have ripple effects across all systems. One example many elite athletes experience is the change in menses, with cycles vanishing altogether during periods of intense training.[7] Another you might not be familiar with is how it impacts your appetite with some reporting a voracious appetite, while others report none. In one study of male power-trained athletes, there was a significant reduction in food consumption and ghrelin concentrations, the hormone responsible for making you hungry.[8]
If you think that you might be over-exercising, it is important to take a step back and assess your situation. This means taking a break from your workouts and seeing how you feel after a few days. If you still feel tired and stressed, it is likely that you are over-exercising. In this case, it is important to see your care provider so that they can help you create a plan to get back on track. They will be able to do some tests to determine if you are over-training and can give you the best advice on how to proceed.
Oftentimes, when it comes to our health, more is not always better. This is definitely the case when it comes to over-exercising. Signs that you might be over-training include an increased resting heart rate, high blood pressure, decreased heart rate variability, and loss of menses or appetite.
Your ND can work with your care team to support your long-term health.
Reference
Ruegsegger, Gregory N., and Frank W. Booth. "Health benefits of exercise." Cold Spring Harbor perspectives in medicine 8.7 (2018): a029694.
Johnson, Mary Black, and Steven M. Thiese. "A review of overtraining syndrome—recognizing the signs and symptoms." Journal of athletic training 27.4 (1992): 352.
Dressendorfer, Rudolph H., Charles E. Wade, and Jack H. Scaff Jr. "Increased morning heart rate in runners: a valid sign of overtraining?." The Physician and Sportsmedicine 13.8 (1985): 77-86.
Stewart, Kerry et al., "Exaggerated Exercise Blood Pressure is Related to Impaired Endothelial Vasodilator Function," American Journal of Hypertension, April 2004;17(4):314-320.
Morales, José, et al. "Use of heart rate variability in monitoring stress and recovery in judo athletes." The Journal of Strength & Conditioning Research 28.7 (2014): 1896-1905.
Laddu, Deepika R., et al. "25-year physical activity trajectories and development of subclinical coronary artery disease as measured by coronary artery calcium: the coronary artery risk development in young adults (CARDIA) study." Mayo Clinic Proceedings. Vol. 92. No. 11. Elsevier, 2017.
Cho, Geum Joon, et al. "Effects of intensive training on menstrual function and certain serum hormones and peptides related to the female reproductive system." Medicine 96.21 (2017).
Oshima, Satomi, et al. "Changes in stress and appetite responses in male power-trained athletes during intensive training camp." Nutrients 9.8 (2017): 912.