“Normal” resting heart rate for a human is between 60-100 beats per minute (bpm). Athletes are often lower than this due to training adaptations in their heart. Basically, a larger ventricle (chamber) size and strong heart muscles enables them to pump more blood with each heart beat, and their peripheral structures such as blood vessels, muscles and cells are more efficient at extracting and using oxygen from each heartbeat.
Fun fact: The lowest recorded heart beat was Daniel Green in 2014, with 26 bpm. Mr. Green has a long run training history!
Resting heart rate is a very simple measure to use, and is not only indicative of fitness, but can also be a predictor for mortality and chronic disease risk, amongst MANY other things. This current article will focus on its use as an indicator of training status.
The heart rate is very responsive to changes in the Autonomic Nervous System, which includes the “fight, flight or freeze” (Sympathetic Nervous System – SNS) and “rest and digest” (Parasympathetic Nervous System - PNS) pathways. Stimulating the SNS increases heart rate, stress hormones, breathing rate and all the things we associate with being excited or afraid. The PNS is associated with decreasing heart rate, breathing rate, relaxation hormones and things like sleep. Ideally, each day includes a healthy balance of each of these systems, but the SNS can often be more dominant, especially in the hustle and bustle of most people’s lives.
In relation to training, workouts can be targeted towards stimulating either the SNS or PNS. Generally speaking, a high intensity type workout such as anaerobic intervals or strength training will stimulate the SNS and a low intensity workout such as an easy spin, gentle run or yoga may stimulate the PNS.
It should be noted that these are fairly general statements and there is a LOT of individuality when applying these concepts to one’s own training.
Resting heart rate can come into play by doing something like measuring it every morning. With daily measurements, you can get a general picture of what your resting heart rate usually is and you will likely find it to be quite consistent. You may see it change the morning after an intense training day, a particularly chaotic day at work/school or when you are getting sick. Tracking it over time allows you to monitor your body’s response to certain types of workouts (eg. You may find that 30s sprint interval workouts always elevate your resting heart rate the most) and guage more specifically where to take your training on any given day.
For example: If you are supposed to be on a rest week and find that your resting heart rate is a bit elevated, perhaps you need to change up your rest strategy (some athletes have a slightly skewed idea of “rest”) or consider some more PNS stimulating activities.
How to measure:
Resting heart rate should be measured and recorded first thing in the morning, immediately after waking up. Consistency of measurement is key to use this as a valid monitoring tool. Record the heart rate every morning with the same routine and monitor its changes over time. You should notice that any outlying measurements (suddenly high or increasing trends in resting heart rate) correspond to previous events or things like an increased training load. These should be compared to your current training phase/goals. It could be intentional to temporarily put extra stress on the body, and training adjustments CAN be made accordingly. Note: this is not an exact science, there are MANY things that can affect heart rate and this should simply be used as another tool in the kit to assess training effectiveness and readiness to train.
If you would like an Excel document for monitoring resting heart rate, send us an email and we can pass one along! As always, feel free to contact us if you have any questions regarding the information above or are curious about anything else. Below are a couple of resources if you’d like to do some reading for yourself, including some information on Heart Rate Variability (a whole further topic!).