study population
Marathon runners were recruited prospectively at
an exposition one or two days before the Boston
Marathon, in April 2002. All registered participants
18 years of age or older were eligible, regardless of
whether they registered for the marathon on the basis
of a competitive qualifying time or on behalf of a
charitable organization — a mechanism for which
no previous marathon experience was required.
Subjects were approached at random in an area adjacent
to race registration and invited to participate.
Written informed consent was obtained from all
subjects. The study protocol was approved by the
Committee on Clinical Investigation at Children’s
Hospital in Boston.