A Case Study of Ironman Training in a 50 year old Triathlete

Abstract

1412 The popularity of triathlon competition has created a quest for participation in a full ironman distance (swim 3.8 km, cycle 180 km, run 42.2 km) by many recreational athletes. Although sprint and Olympic distance triathlons are exponentially growing in number with numerous first time participants, the interest in ironman distance participation is also rapidly expanding. Entry into these long endurance events is often closed after only 3 – 7 days. Ironman participants generally cross train year round for all three events and during the final 4 – 6 months prior to competition train 6–7 days/week at a weekly duration of 12–25 hours/week. PURPOSE: This study followed the training and physiological markers during 22 weeks of triathlon cross training on a 50 year old recreational triathlete. Methods: This novice ironman distance triathlete (ht. 173 cm; mass 73.6 kg, finish time 713 minutes), who had completed over 150 triathlons in the past 20 years, and competed in endurance racing for over 30 years, participated in a double maximal oxygen consumption test (Max VO2 on treadmill and cycle) every 4 weeks for 22 weeks prior to the ironman race. Bone mineral density and body composition was obtained by DEXA. Results: For this abstract, only initial (I) and final (F) 26 week data are reported. Total bone density (g/cm) was 1.532 vs 1.540, body mass 75.5 vs 71.2 kg., body fat 16.8 vs 13.3 %, and lean body mass was 62.9 vs 61.7 kg, for I and F assessments, respectively. Maximal treadmill testing revealed 57.7 vs 58.8 mL O2/kg-m, max HR 166 vs 168 b/m, peak lactate 12.3 vs 8.9 mMole, and anaerobic threshold (AnT) of 90 vs 91% of max VO2, for I and F assessments, respectively. Maximal cycle ergometer testing revealed 52.8 vs 55.3 mL O2/kg-m, max HR 158 vs 157 b/m, peak lactate 10.7 vs 9.6 mMole, and AnT of 78 vs 81% of max VO2, for I and F assessments, respectively. Conclusion: With 297 hours of exercise (13.5 hrs/wk, range 7.25 – 18.8) within 22 weeks and a workout intensity of 22% high (>AnT), 63% moderate (no more than 20% below AnT), and 15% easy (>20% below AnT), this athlete was able to maintain bone density, aerobic power and reduce body fat. The exceptionally high bone density may in part be attributed to a lifetime of physical exertion and the physical stress imposed on the lower extremity during run and cycle training.