By Adam Kimble

This is the fourth and final chapter in our story about distance runner, Adam Kimble. Earlier this spring, Adam, 29, made a heroic attempt to break the 36-year-old world record for running across the U.S. (44 days). This final chapter is about the physiological data Adam collected through nearly daily testing during his journey and what what it taught him - and us.

Adam reviewing some of his measurements while refueling.

Beginning of Adam's journey on the Pacific Coast.

Adam’s journey took a total of 60 days. He ran for 55 days and rested for only five. Adam took Ember measurements on 42 of the 55 days he ran – totaling 58 measurements, and an average of approximately 1.4 measurements per each running day. The most measurements he took in one day were four. Adam also recorded his energy level on the days he ran using a self-assessment scale of 1 to 5 (1: low energy, 5: high energy). By measuring fairly consistently over the course of his journey, Adam developed some interesting trends – particularly regarding his ‘first-of-day’ measurements.

Adam and his wife & crew leader, Karen.

Adam reviewing some of his measurements while refueling.

Based on our analysis of Adam’s data, here are three key observations:


One: Adam’s first-of-day hemoglobin values trended downwards throughout his journey, whereas his first-of-day pulse rate trended upwards – both indicators of overtraining.


Central Facts / Points:

  • Prior to the start of his journey, Adam’s hemoglobin and pulse-rate values averaged 16.1 g/dl and 61.2 bpm, respectively.
  • During the first 30 days of his journey, Adam’s average hemoglobin value fell to 15.7 g/dl and his average pulse-rate value rose to 64 bpm.
  • During the last 30 days of his journey, Adam’s average hemoglobin value fell further to 15.3 g/dl and his average pulse-rate value climbed even higher to 67.3 bpm.
  • By the end of the journey, his resting heart rate had increased by more than 10%. Needless to say, Adam was consistently “overtraining” most of the journey to accomplish his incredible goal.
  • After two weeks of well-deserved rest at the end of his feat, Adam returned to his normal routine of training and usual ‘work-related’ activities. His average, first-of-day pulse-rate value dropped to 55 bpm; but his average hemoglobin value of 14.8 g/dl was still lower than where he first started out. This stands to reason that it takes a while for the body to regenerate new red blood cells (RBC) after two months of punishment!

Cold morning!

Two: Adam’s first-of-day hemoglobin values generally correlated to his ‘energy-level’ score. When his hemoglobin values were low, his energy-level score was low; and when his hemoglobin values were high, his energy-level score was high.

Crossing the George state line.


Central Facts / Points:

  • On the seventh and eighth days of his journey, Adam had low, first-of-day hemoglobin values at 14.1 g/dl and 14.6. During those two days, he had the lowest energy level score of 1 and 2, respectively.
  • After resting for three days, his first-of-day hemoglobin value went back up to 16.4 and his energy level score had gone up to 5.

Three: Adam’s hemoglobin data from Ember appears to show a trend with lower values following the days he ran longer distances. This situation has been reported by J. Wilkinson in the International Journal of Sports and Exercise Medicine, where Wilkinson reported a significant decrease in the hemoglobin concentration observed 24 hours or more following a post-exhaustive endurance exercise.

Adam leading a crew meeting.


Central Facts / Points:

  • When Adam ran more miles than the previous day, his next first-of-day hemoglobin value was generally lower than the previous first-of-day hemoglobin values.
  • Example 1: On day 30, Adam ran 50.2 miles – 25 more miles than the previous day (day 29). His next first-of-day hemoglobin value on day 31 was 16.1 g/dl, which was .4 g/dl less than the previous day.
  • Example 2: On day 13, Adam ran 50 miles – nine miles more than the previous day (day 12). His next first-of-day hemoglobin value on day 14 was 15.9 g/dl, which was .9 g/dl less than the previous day.
  • When Adam ran fewer miles than the previous day, his next first-of-day hemoglobin value was generally higher than the previous first-of-day hemoglobin values.
  • Example 1: On day 29 Adam ran 24.7 miles – 21 fewer miles than the previous day (day 28). His next first-of-day hemoglobin value on day 30 was 16.5 g/dl, which was .5 g/dl higher than the previous day.

Example 2: On day 40, Adam ran 25.9 miles – nearly 18 miles less than the previous day (day 39). His first-of-day hemoglobin value on day 40 was 16.3 g/dl – 1.3 g/dl higher than the previous day.