Week 8: Resting and resting heart rate

• Weight (7d avg): 186.9lbs/84.8kg, from peak -12.8lbs/-5.8kg

• RHR (7d avg): 59.4bpm

• Calories In (7d avg): 1686kcal

• Exercise (7d avg): 500kcal

• Net Deficit (total): -2300kcal

• 2x5x500m row: 1:51.0, 1:49.6

Notes:

I saw a continued steady decline in my weight 2 weeks after my sleep apnea surgery. Recovery was slow but continual. Though I had hoped to be mostly recovered 2 weeks in, I was just starting to be able to eat normally again throughout the week. My decreased diet meant exercising was difficult. But as soon as I was able to increase my calories I was able get back to my gym routine.

One additional goal I had for this weight loss challenge was getting my resting heart rate down closer to where I was a few years prior, in the low 50s. As I entered my mid thirties, my RHR seemed to go up 1 bpm every year. It's difficult to say what caused this but I was very interested in seeing what I could do to get it back down.

Anecdotally, the more weight I lost and more exercise I got, the better my RHR. However, getting sick or recovering from surgery caused my RHR to rise within a few days. There's 3 categories I'm interested in when considering RHR impacts: weight loss, exercise, and illness.

Weight Loss

A meta-analysis from 2019 found an associated -9bpm with large median weight loss of 43kg. This ranged from 20% to 30% weight loss. In a 1 year controlled trial , RHR decreased by 4bpm with a 5-10% decrease in weight. There are several other confounding factors including diet and exercise that could also impact RHR, but generally weight loss seems to have a consistent effect.

Exercise

Easily the most well studied factor for improving RHR, a large systematic review and meta-analysis published in 2018 showed -5.2bpm from all types of sports, -6.0bpm from endurance training, and -2.5bpm from strength training. Notably, studies showed -7.2bpm from yoga specifically. These adaptations took several weeks to see drops, but I see impacts from my Fitbit within a few days of high aerobic activity.

Illness

I always see a spike in my RHR when I get sick and it can be quite discouraging. I try to keep my spirits up by reminding myself its temporary. A national US study looking at the relationship between body temperature and heart rate found a HR increase of 7bpm for every increase in T of 1.0°C or 1 .8°F. Diseases like COVID-19 saw increases of 1.8% for females and 3.4% for males on initial onset.