1. Write the null hypothesis (using words, not symbols, please).
2. Write a conclusion relative to the null hypothesis

OBJECTIVES:Although alternating run/walk-periods are often recommended to novice runners, it is unclear, if this particular pacing strategy reduces thecardiovascularstress during prolonged exercise. Therefore, the aim of the study was to compare the effects of two different running strategies on selected cardiac biomarkers as well as marathon performance.

METHODS:Male (n=22) and female subjects (n=20) completed a marathon either with a run/walk strategy or running only. Immediately after crossing the finishing line cardiac biomarkers were assessed in blood taken from the cubital vein. Before (-7 days) and after the marathon (+4 days) subjects also completed an incremental treadmill test.

RESULTS:Despite different pacing strategies, run/walk strategy and running only finished the marathon with similar times (F= 0.8, p=0.377). In both groups, prolonged exercise led to significantly increased B-type natriuretic peptide, creatine kinase MB isoenzyme and myoglobin levels immediately after the marathon. After 4 days plasma concentration of CK-MB and myoglobin dropped to a level that was not significantly different from baseline. BNP levels in RWS also lowered to baseline values 4 days after the running; BNP levels inRUN remained elevated in comparison to 7 days before the marathon. B-type natriuretic peptide (r=-0.363; p=0.041) and myoglobin levels (r=-0.456; p=0.009) were inversely correlated with the velocity at the individual anaerobic threshold. Run/walk strategy compared to running only reported less muscle pain and fatigue (p=0.006) after the running event.