The purpose of this case study was to investigate the recovery phase in a single athlete after a Triple Iron Triathlon involving 11.4 km swimming, 540 km cycling and 126.6 km running. Total body mass, body fat and skeletal muscle mass using the anthropometric method as well as total body water using bioelectrical impedance analysis were determined pre race, after the race and every 24 hours until complete recovery. Parameters of hydration status (urinary specific gravity, hematocrit and plasma sodium) and skeletal muscle damage (plasma urea) were measured at the same time. After finishing the race within 42 hours, total body mass was decreased and total body water was increased. Over the following 6 days, prior to returning to pre race values for plasma volume and total body water, body mass reached a peak value on day 3, plasma volume on day 2 and total body water on day 1. Clinically visible edemas of the feet persisted until day 4. Six days after the race, body mass was reduced by 2.1 kg, skeletal muscle mass by 0.6 kg and fat mass by 0.7 kg. An increase in both blood urea and urinary output post race between days 3 and 6 suggested an impairment of renal function immediately post race due to skeletal muscle damage and manifesting clinically observed edemas. For practical application, athletes, coaches and physicians should anticipate that performing such an ultra-endurance race can lead to considerable edemas of the lower limbs during the recovery phase.