Oct122025October 12, 2025October 13, 2025by Masters TTRacer

Recorded 38 BPM Resting Heart Rate Twice

Posted in Training Reports

PREPARATION 1.7 REPORT (10/06 – 10/12)

HIGHLIGHTS: I’ve recorded a resting heart rate of 38 beats per minute (BPM) twice this past week. Usually, my resting heart rate is around 40 BPM. During the past couple of weeks, I’ve recorded consecutive 39 BPM resting heart rates. I log my heart rate continuously around the clock and post it to an online exercise data respository for later analysis. I know exactly when and for how long the 38 BPM heart rates occurred. The first occurance was Tuesday morning from 12:34 AM to 1:16 AM. The second occurance was Friday morning from 12:50 AM to 1:12 AM.

Is it dangerous to have such a low resting heart rate? Yes, if the individual is not a trained athlete. If that individual is also experiencing dizziness, lighheadedness, chest discomfort, or fainting, a visit to a doctor is highly advised. Otherwise, a low heart rate between 40 to 60 bpm is the result of an athlete’s heart’s adaption to cardio training called “cardiac remodeling.” This means the heart is stronger and more efficient. There are four ways the heart adapts to training:

  • Stronger muscle: Cardiovascular exercise, especially endurance training, strengthens the heart muscle, especially the left ventricle.
  • Larger chambers: The heart chambers may enlarge, allowing for a larger volume of blood to be pumped with each contraction (increased stroke volume)
  • Increased efficiency: With these adaptations, the heart becomes more efficient, pumping more blood per beat. Consequently, it takes fewer beats per minute to circulate the necessary blood flow, leading to a lower resting heart rate.
  • Improved circulation: Training also leads to a greater density of capillaries in the muscles, which helps deliver oxygen more efficiently.

Is this the lowest resting heart rate I’ve ever recorded? No. I participated in a university-sponsored study of elite runners after I left college. At the time, I was in my mid-20s and running a 100 miles per week. My resting heart rate was recorded at 30 bpm. The second time was in my early 50s after I was hospitalized for observation after suffering an apparent mini-stroke due to training too intensely (without a heart rate monitor). During the night, my resting heart rate dropped to 30 bpm.

All indoor cycling sessions were completed with my recumbent trike on a Kinetic by Kurt Road Machine smart trainer + Rouvy application. Three strength resistance workouts were completed.

DETAILS:

  • Monday’s Foundation Hi/Lo Blend (3 x 5/4 minutes) workout was 15.75 miles in 1:05:00. Average speed was 14.5 mph; maximum speed was 16.6 mph. Average power was 78 watts; maximum power was 122 watts. A 30-minute strength machine resistance workout was completed.
  • Tuesday’s Recovery – Endurance Blend workout was 12.22 miles in 0:50:00. Average speed was 14.7 mph; maximum speed was 16.9 mph. Average power was 80 watts; maximum power was 137 watts.
  • Wednesday’s Aerobic Tempo Intervals (6 x 3/3 minutes) workout was 14.04 miles in 0:56:00. Average speed was 15.0 mph; maximum speed was 17.1 mph. Average power was 85 watts; maximum power was 140 watts. A 30-minute strength machine resistance workout was completed.
  • Thursday was a rest day off the bike.
  • Friday’s Foundation Medley Intervals (6 x 6/3 minutes) workout was 17.29 miles in 1:11:00. Average speed was 14.6 mph; maximum speed was 16.6 mph. Average power was 78 watts; maximum power was 121 watts. A 30-minute strength machine resistance workout was completed.
  • Saturday’s Recovery – Endurance Miles workout was 11.07 miles in 0:47:00. Average speed was 14.1 mph; maximum speed was 15.2 mph. Average power was 73 watts; maximum power was 94 watts.
  • Sunday’s Trainer Workout Foundation workout was 17.14 miles in 1:08:00. Average speed was 15.1 mph; maximum speed was 17.0 mph. Average power was 85 watts; maximum power was 126 watts.

BY THE NUMBERS:

  • Total Distance: 87.52 mi
  • Longest Ride: 17.29 mi
  • Total Time for Week: 7:27:00 (h:m:s)
  • Avg Speed: 14.7 mph
  • Max Speed: 17.1 mph
  • Avg Power: 80 watts
  • Max Power: 140 watts
  • Calories: 2,240 C
  • Avg Weight: 175.9
  • Chronic Training Load: 29 (0)