17th Annual ECSS-Congress, Bruges 2012

Abstract details

Abstract-ID: 589
Session: [OP-PM23] Physiology: Energy metabolism
Lecture room: Live 7
Date & time: 26.06.2015 / -
Title of the paper: Ultra endurance exercise and changes in lean mass
Authors: Furber, M.J.W., Anton-Solanas, A.
Institution: GlaxoSmithKline
Department: Human Performance Lab
Country: United Kingdom
Abstract text Introduction In ultra endurance events the ability to maintain body mass is often compromised due to a restricted energy intake and high energy expenditure. The following case report details the body composition changes of 6 athletes competing in 4 different ultra endurance events. Methods The athletes observed took part in 4 different ultra endurance events. Three male athletes (39.47.1 years) participated in the 2014 Marathon des Sables (running 251 km in 6 days); one female athlete (38.1 years) participated in the 2014 solo Race Across America (cycling 2,150km and withdrew after 9 days due to injury); one male athlete (36.4 years) skied from the coast of Antarctica to the South Pole (1,150 km in 29.8 days); and one male athlete (36.1 years) skied from the Antarctic coast to the South Pole and back (2,888 km in 105 days). Each athlete received comprehensive, structured nutrition and physiology support. Body composition was measured as close as possible pre and post each event (11.612.1 and 8.15.7 days, respectively) using dual energy x-ray absorbitometry. Results No significant difference was detected in total body mass (BM) between pre and post event (84.4310.72 vs. 81.9310.44 kg) across all challenges, however in the events lasting >10 days (>10 d) a mean BM loss of 5.651.91 kg was observed compared to 0.930.88 kg in <10 days (<10 d) events. Total lean mass (LM) increased significantly post event (64.0711.58 to 65.0011.99 kg); the trunk region exhibited the greatest increase (29.434.83 to 30.935.45 kg). In events lasting >10 d trunk LM increased by 2.680.73 kg compared to 0.920.73 kg in events lasting <10 d. Limb LM demonstrated a greater decrease in >10 d events (-1.690.28 vs. -0.020.58 kg). In the weight bearing challenges, bone mineral density (BMD) significantly decreased (1.3930.17 to 1.3800.169 mg/cm2); no changes were observed in the cyclist. Discussion The data presented demonstrate that multi-day exercise can result in increases in lean mass, the trunk exhibiting the greatest increase. In the two >10 d events the athletes were pulling a sled (>60 kg weight) resulting in a heavy isometric load on the trunk and a repetitive low resistance load on the limbs. This unique combination of exercise potentially led to the observed increases in trunk LM and decreases in limb LM. Similar but lower magnitude body composition changes were observed in <10 d events, highlighting the impact exercise duration has on body composition change. It is well established that impact exercise can support gains in BMD; however the current data demonstrate a significant decrease in BMD in the high impact challenges. These findings suggest research is required to better understand body composition changes during ultra endurance.
Topic: Physiology
Keyword I: Body Composition
Keyword II: Ultra Endurance
Keyword III: Lean Mass