Key result
Downhill running, which generated 11% greater foot impact force, caused significantly greater increases in plasma free hemoglobin and decreases in haptoglobin than uphill running (P<0.05).
Why the study?
Does downhill running (greater foot impact force) increase intravascular hemolysis compared to uphill running in male distance runners?
RCT (n=14)
Randomly ordered crossover
Does downhill running (greater foot impact force) increase intravascular hemolysis compared to uphill running in male distance runners?
Greater foot impact force during downhill running is associated with increased intravascular hemolysis, supporting mechanical trauma to red blood cells at footstrike as a major cause of running-induced hemolysis.
Answers are grounded in this paper and cite their sources.
Downhill running may heighten hemolysis risk in distance runners; confirms footstrike impact as a causal mechanism in exercise-induced anemia.
This study was designed to examine the relationship between foot impact force and the magnitudes of the changes in markers of intravascular hemolysis during distance running. Fourteen male distance runners (VO2 max = 66.1 +/- 5.0 ml.kg-1.min-1, mean +/- SD) completed two treadmill runs and a resting control procedure. The two treadmill tests involved running at 215 m.min-1 for 10,000 footstrikes at elevations of either +6% (uphill) or -6% (downhill). Mean foot impact force was 11% greater with the downhill than the uphill running. The three procedures were ordered randomly and separated by 7 days. Hemoglobin concentration (Hb), hematocrit (Hct), plasma free hemoglobin (PFHb), and haptoglobin (Hp) concentrations were assayed in blood samples collected via venipuncture 15 min and immediately before exercise, and immediately, 1 h, and 2 h after the exercise. Repeated measures ANOVA revealed that Hp was significantly decreased and PFHb was significantly increased after treadmill running (P less than 0.05) and that these changes were significantly greater with downhill than uphill running (P less than 0.05). These findings support the theory that mechanical trauma to red blood cells occurring at footstrike is a major cause of hemolysis during running.
No takes yet. Share an insight, caveat, or question.
Miller et al. (1988) conducted an RCT in Intravascular hemolysis during running (n=14). Downhill treadmill running (-6% elevation) vs. Uphill treadmill running (+6% elevation) and resting control was evaluated on Changes in markers of intravascular hemolysis (plasma free hemoglobin and haptoglobin) (p=<0.05). Downhill running, which generated 11% greater foot impact force, caused significantly greater increases in plasma free hemoglobin and decreases in haptoglobin than uphill running (P<0.05).
Synapse has enriched 10 related papers. Consider them for comparative context: