Understanding the signs of a overloaded system
Keeping an eye on three simple biomarkers: heart rate, respiration rate, and body temperature can provide you insight to if you are getting sick, fatigued, or overtraining. When your body is in one of these states, it starts to require more energy to combat the additional stress. This increased energy utilization can alter the above mentioned biomarkers in specific ways. By monitoring these biomarkers you can prevent illness, adapt your training schedule, and optimize your health. Dive into details below to learn how to measure these biomarkers along with the changes you might see.
Body Temperature
Your core body temperature is extremely responsive to what is happening inside your body. As your body deals with stress, illness, or trauma, it triggers an immune and inflammatory response which can raise your body's temperature. Expect to see a normal variation of 1-2 degrees daily, with variation beyond this meaning you may be overtraining, getting sick, or fatigued. Body temperature can also be altered by extrinsic factors. Climate and exercise can artificially raise or lower your body temp and because of this, your daily body temperature readings should be performed in a consistent environment. We recommend taking your temperature first thing in the morning upon waking.
The most accurate core temperature reading is obtained through a rectal thermometer, however most people are not willing to go this route. Ultimately, consistency is more important than accuracy so as long as you always use the same device, you should get an accurate representation of trends. We recommend oral thermometers as they are inexpensive and easily accessible. Temporal or ear thermometers are also good options, however they tend to be more pricey.
Combat an upward trend in body temperature with increased rest, hydration, healthy eating, and by decreasing stress to optimize the body's ability to heal itself.
Heart Rate
There are two objective measures you can look at when assessing your heart's response to systemic inflammation, illness, or overtraining: resting heart rate (RHR) and heart rate variability (HRV).
Resting Heart Rate - When your body is stressed, it engages the sympathetic nervous system (fight or flight) which elevates your resting heart rate. By tracking your resting heart rate and looking for increasing trends, you can begin to understand when the body is in this flight or fight mode. The best time to assess your resting heart rate is upon waking as this tends to be when our resting heart rate is the lowest. You do not need any equipment to measure your rest heart rate. Just count your heart beats via the radial or carotid artery for 30 seconds and multiple by 2 to obtain this measure.
Heart Rate Variability - HRV is a measure of the differences in time between the beats of your heart. A larger variability in the time between heart beats is an indicator of a heart that is not stressed and is linked to your body utilizing your parasympathetic nervous system (rest and digest nervous system). Measuring HRV requires some equipment. There are many devices like the Oura Ring or Whoop Strap that will measure this for you, however you can also obtain this with cheaper options such as a heart rate monitor strap and a free app on your phone.
When you notice an increase in your resting heart rate or decrease in your HRV this could be an indicator that you have a high level of stress in your life. Like with an increase in body temperature, try to increase rest, hydration, healthy eating and decrease stress to optimize the body's ability to heal itself.
Respiration Rate
Respiration rate, like heart rate and body temperature, is closely connected to your body’s nervous system and will be affected as you become sick or fatigued, stimulating a sympathetic nervous system response. Stimulation of the sympathetic nervous system will increase your respiration rate. Respiration rate is easy to track: it's free and just takes 30 seconds. Upon waking, count your breaths for 30 seconds, then times by 2 to get your respiration rate. Gadgets like the Whoop Strap and Oura Ring can also help track your respiratory rate for you. If you see a steady increase over a few days, it is a good indicator that something is amiss. Take the precautions listed above to counter the sickness or fatigue.
Overview
Keeping an eye on these biomarkers may shed some light on what’s going on inside your body. Make sure to track these markers over the course of 2-3 weeks to obtain baseline levels. Some variation day to day is expected and a baseline range is needed to provide the ability to understand when you are out of balance.
For our athletes, these above measures can also help you identify when rest is needed due to overtraining. When the body is overtrained, it will have a similar reaction to when you are getting sick, causing excessive stimulation of the sympathetic nervous system and causing changes to these biomarkers. These markers will help you become a smarter athlete by teaching you to become in-tune to your body's response to training. After a hard training day, it is not uncommon to see your HRV drop and resting heart rate rise. You can begin to track how your body responds or tolerates certain workouts or activities and perhaps how to better incorporate them into your training appropriately to optimize your performance.
There are also a multitude of lifestyle factors that can affect these biomarkers including, but not limited to, sleep, alcohol consumption, timing of caffeine consumption, late night meals, and increased stress. If you would like more information on this subject or would like a consultation on how to most effectively use these biomarkers to aid in your health or rehabilitation, reach out to us at White Mountain Physical Therapy to schedule a consultation.