1. Running USA – Chronological Evolution of Athletes Participating in Running Events. http://www.runningusa.org/statistics (accessed 26.04.17).
2. Triathlons USA – Chronological Evolution of Athletes Participating in Thriatlon Events. https://www.statista.com/statistics/191339/participants-in-triathlons-in-the-us-since-2006/ (accessed 26.04.17).
3. An empirical study of race times in recreational endurance runners;Vickers;BMC Sports Sci. Med. Rehabil.,2016
4. A Longitudinal Assessment of Anaerobic Threshold and Distance-running Performance;Tanaka,1984
5. Validity and reliability of ventilatory and blood lactate thresholds in well-trained cyclists;Pallarés;PLOS ONE,2016