The impact of chronic carrier of hepatitis B virus on liver function in a 7-day ultramarathon race.

BACKGROUND: Several changes in physiological characteristics occur during long-distance and 24-hour ultramarathons, including hyponatremia, skeletal muscle breakdown, plasma volume changes, iron depletion, anemia, and possible hepatic damage. The purpose of this study was to investigate the impact of hepatitis B virus (HBV) carrier status on liver function during multi-day races. METHODS: This prospective study recruited 10 Taiwanese runners who were scheduled to participate in the 7-day 2008 Athens Ultramarathon Festival Race, and three of them were chronic carriers of HBV. Blood samples were collected before, during, and 3 days after the race, including alkaline phosphatase (ALP), albumin (ALB), total protein (TP) levels, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and total bilirubin (T-BIL) RESULTS: Ten Taiwanese runners (40% female; average age 52.3 ± 7.9 years) who all planned to run in the race were recruited. Three runners were chronic carriers of HBV (HBV carrier), and all participants were anti-HCV antibody-negative and anti-hepatitis A virus (HAV) IgG-positive. There were no significant time-by-group effects on ALP, ALB, and TP levels, but the change over time effects were significant (p < 0.001, p = 0.001 and p = 0.010, respectively). ALT, AST, and T-BIL increased significantly to markedly higher levels in the HBV carrier group compared to the non-carrier group (group effect p = 0.009, p = 0.004, and p = 0.05, respectively), and the time-by-group interaction was also significant for these liver function markers (p < 0.001, p < 0.001, and p = 0.001, respectively). CONCLUSION: Compared to their counterparts, runners who are HBV carriers had significantly greater increases in levels of ALT, AST, and T-BIL during a 7-day ultramarathon, indicating that the liver function of carriers is more highly impacted in these races.

Effects of 100-km ultramarathon on acute kidney injury.

OBJECTIVE: To evaluate the prevalence and characteristics of acute kidney injury (AKI) in 100-km ultramarathon runners. DESIGN: Prospective observational study. SETTING: The 2011 Soochow University ultramarathon, in which each athlete ran for 100 km. PARTICIPANTS: All Taiwanese entrants who participated in the 100-km race and lived in the northern part of Taiwan were invited to participate in the study. MAIN OUTCOME MEASURES: Acute kidney injury was defined using the Acute Kidney Injury Network criteria. Blood and urine samples were collected 1 week before, immediately after, and 1 day after the race. RESULTS: Immediately after the race, 85% (22) of the 26 subjects were diagnosed with AKI, 65% (16) with moderate dehydration, 23% (6) with muscle cramps, and 12% (3) with hematuria. Body weight was significantly decreased from prerace to all postrace measurements. Plasma levels of potassium ion, creatinine, renin, and aldosterone were significantly elevated immediately after the race and then significantly reduced 1 day after the race. Changes in plasma levels of sodium, creatine kinase, and creatine kinase-MB, as well as urine potassium and creatinine, were indicative of AKI. CONCLUSIONS: Transient AKI and muscle cramps are very common in 100-km ultramarathon runners. All transient ultra-runners who developed AKI in this study recovered their renal function 1 day later. CLINICAL RELEVANCE: Ultramarathon running is associated with a wide range of significant changes in hematological parameters, several of which can be associated with potentially serious renal and physiological abnormalities.

Impact of Center-of-Mass Acceleration on the Performance of Ultramarathon Runners.

Ultramarathon races are rapidly gaining popularity in several countries, raising interest for the improvement of training programs. The aim of this study was to use a triaxial accelerometer to compare the three-dimensional center-of-mass accelerations of two groups of ultramarathon runners with distinct performances during different running speeds and distances. Ten runners who participated in the 12-h Taipei International Ultramarathon Race underwent laboratory treadmill testing one month later. They were divided into an elite group (EG; n = 5) and a sub-elite group (SG; n = 5). The triaxial center-of-mass acceleration recorded during a level-surface progressive intensity running protocol (3, 6, 8, 9, 10, and 12 km/h; 5 min each) was used for correlation analyses with running distance during the ultramarathon. The EG showed negative correlations between mediolateral (ML) acceleration (r = -0.83 to -0.93, p < 0.05), and between anterior-posterior (AP) acceleration and running distance (r = -0.8953 to -0.9653, p < 0.05), but not for vertical control of the center of mass. This study suggests that runners reduce stride length to minimize mediolateral sway and the effects of braking on the trunk; moreover, cadence must be increased to reduce braking effects and enhance impetus. Consequently, the competition level of ultramarathons can be elevated.

Urine output and performance of runners in a 12-hour ultramarathon.

OBJECTIVE: To understand the urination pattern and to determine the relationships between urine output and performance of ultramarathon runners. DESIGN: Prospective observational study. SETTING: The 2005 Soochow University international ultramarathon, in which each athlete ran for 12 hours. PARTICIPANTS: All entrants in the 12-hour race were invited to participate in the study. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Athletes were weighed immediately before and after the race. Urine samples were collected during the race and immediately after the race. RESULTS: There was a trend toward better performance of the group with less urination (LU), although the difference was not statistically significant. Further analysis of hourly running distances between groups showed better performance in the group with LU during the first 11 hours of the competition. Comparison of athletes in 3 levels of running distance (tertiles) showed statistically significant differences between groups in total urine output. The fastest tertile had lower prerace body weight and greater body weight change than the slowest and intermediate tertiles, but the differences were not statistically significant. Linear regression analysis using the stepwise method showed that total urine output and prerace body weight were negatively associated with performance. CONCLUSIONS: Runners with LU had better performance during the first 11 hours of the competition. Linear regression analysis showed that total urine output and prerace body weight were negatively associated with performance.

Athletic performance and serial weight changes during 12- and 24-hour ultra-marathons.

OBJECTIVE: The principal objective of this study was to evaluate serial weight changes in athletes during 12- and 24-hour ultra-marathons and to correlate these changes with athletic performance, namely the distance covered. DESIGN: This was a prospective study. SETTING: The 2003 Soochow University international ultra-marathon. PARTICIPANTS: Fifty-two race participants. INTERVENTIONS: 12- or 24-hour ultra-marathon. MAIN OUTCOME MEASUREMENTS: Body weight changes were measured before, at 4-hour intervals during, and immediately after the 12- and 24-hour races. RESULTS: Significant overall decreases in body weight were apparent at the conclusion of both races. The mean relative body weight change after the 12-hour race was -2.89 +/- 1.56%, ranging from 0 to 6.5%. The mean relative body weight change after the 24-hour race was -5.05 +/- 2.28%, ranging from -0.77% to -11.40%. Of runners in the 24-hour race, 26% lost greater than 7% of baseline body weight during the race. During both the 12- and 24-hour races, the greatest weight change (decrease) occurred during the first 4 hours. Weight remained relatively stable after 8 hours, although a further decrease was apparent between 16 and 20 hours in the 24-hour participants. Weight change had no bearing on performance in the 12-hour race, whereas weight loss was positively associated with performance in the 24-hour race. CONCLUSIONS: Our findings demonstrate that the majority of weight decrease/dehydration in both the 12- and 24-hour races occurred during the first 8 hours. Hence, to maintain body weight, fluid intake should be optimized in the first 8 hours for both 12- and 24-hour runners and in 16 to 20 hours for 24-hour marathon runners.