Abstract

The purpose of this case study was to compare the decrement in distance running performance and peak VO₂ over ∼25 years in a runner with type 1 diabetes with those of runners who do not have diabetes. A 58-year-old man was diagnosed with type 1 diabetes at age 12. His blood glucose (BG) management has been tightly controlled, with glycated hemoglobin values averaging just above normal (mean: 6.18%; normal: 4.0–6.0%) for over a 21-year period. His decline in running performance at three distances (800 m, 3 miles, and 10 km), as well as his decrement in relative oxygen uptake (VO₂) peak were compared to active runners not having type 1 diabetes.

All distances run were certified, and his peak VO₂ was assessed in the same laboratory 12 times over a 23-year period. Values for peak VO₂ in all 12 tests across time were at or above the 90th percentile rank in age-matched people without diabetes. The rate of decline in peak VO₂ averaged 0.6% per year. The decrement in run performance per year ranged from 1.0 to 1.5% at the three distances. These values are typical of competitive runners over age 30 who do not have type 1 diabetes.

These results suggest that with vigorous effort to monitor and maintain normal BG levels, a good level of aerobic fitness may be maintained for several decades in people with type 1 diabetes. Also, the decline in running performance with age appears typical of runners not having type 1 diabetes. Consequently, no apparent limitation to peak VO₂ or running performance seems to have occurred over several decades because of the presence of type 1 diabetes.