Determining Rest Times
How do you decide how long to rest between sets? Do you use a timer? Go by how you feel? Do you just do whatever your trainer suggests, or what you’ve heard on the internet?
There is a lot of varying information out there about how long between sets is optimal for reaching your goals, depending on the training style. Like most factors in health and fitness, there isn’t a one-size-fits-all answer. My preferred method of choice seems to be the most individualized, yet the most under-utilized.
I wear a heart rate monitor when resistance training to determine the length of rests. When my heart rate has returned to 50-60% of my estimated heart rate max (HRM), then I know I am ready to hit the next set. For example, during a high-volume leg workout, I will often see my heart rate reach nearly 95% of my HRM (175bpm) by the end of a working squat set. Then I will wait until it drops back down to 60% (115bpm) before beginning the next set. The amount of time this takes is often close to the average 2-3min recommendation from most training and exercise resources for strength training.
However, much like the method of RPE based training, there are multiple factors that can affect how I am feeling from one day to the next and in turn, the rate at which my heart rate decreases – fatigue, hunger, illness, hydration, stress, etc.
A prime example of this adjustment is working out when you are a little under the weather. Not only will the exercises feel more difficult, but you will also notice that your heart rate gets, and stays, slightly higher throughout. On these days, you may need to take longer rests to make sure your body is ready to go for every set. A heart rate monitor for strength training is an excellent tool for measuring your body’s ability to handle different intensities and workloads.
Tracking Recovery
Now let’s discuss how you can use your heart rate monitor between workouts. First, you will need to measure your resting heart rate (RHR) when you are well rested, relaxed and fully recovered (a minimum of 48 hours after your most recent training session). The most accurate reading of RHR will be in the morning, immediately after waking up, before eating or drinking anything. Once you have this benchmark metric, you can begin using RHR as an accurate reading of your post-training recovery status.
If you see an increase in RHR of more than 10%, this is a strong indication of over-training and should prompt you to take some more time to rest before your next training session. If you know that you have not been training near your maximum recoverable volume (MRV) and are not sick but still see an increase in RHR, this should be a trigger to examine other factors such as hydration, sleep, and nutrition. These aspects of health can all cause an increase in RHR.
Tracking Fitness Level
Finally, you can use your RHR to track improvements in general fitness. A lower RHR is often an indication of an athletic or very fit person. A slow decrease in RHR over time is a sign of improved fitness!
