Abstract
Introduction
Multiday physical exertion with limited recuperation can result in an overtraining syndrome. Few studies have examined the performance and physiological adaptations that occur during bicycle touring.
Objective
We sought to characterize potential physiological changes in young bicycle tourists.
Methods
Three fit, healthy, cyclists, aged 23, 25, and 27 years, completed an unsupported, 4506-km bicycle tour through the United States and Canadian Rocky Mountains averaging 112 km/day for 40 days. During the tour, average power output and heart rate were measured weekly using field performance tests. Daily physiological measures included blood pressure, morning heart rate, fasting blood sugar, and salivary cortisol. Peak power (Wpeak), VO2max, maximum heart rate, lactate threshold, and body composition were obtained before and after the tour.
Results
VO2max at baseline was 59.2, 63.9, and 49.2 ml/kg min−1 and increased modestly in all 3 subjects (1.9–6.5 mL/kg min−1) following the tour. Wpeak increased in 2 subjects and slightly decreased in the 3rd though average power output increased for all 3 subjects. Average heart rate remained stable. Lactate threshold, morning heart rate, and power output did not decrease following the completion of the ride. All 3 subjects lost weight (0.6, 2.3, and 2.4 kg). Two of the subjects finished with a lower body fat percentage, while the third gained body fat percentage. There was no consistent change in cortisol levels or other physiologic markers.
Conclusions
In a young healthy group of cyclists, some aspects of performance were enhanced at the conclusion of the 40-day ride, and no evidence of overtraining was seen. Although the number of subjects was limited, this observational study supports that rigorous bicycle touring is safe and may provide a training stimulus under these conditions. Future studies should verify these findings in a larger cohort of older or less fit subjects or following a longer tour.