In medical studies, treatments are tested within a group of study participants. You will be given a sentence of a study report in which your task is to list the phrases that give information about the participants of the study. You should list the phrases in the same order that they appear in the text, separated by commas. If no information about the participants is mentioned, just output "not found". Relevant information about participants include: gender, medical conditions, location, number of people participating. Do not contain participant mentions without relevant information.

[Q]: Previous analyses that focused on health care underestimated this economic burden , particularly for school systems .
[A]: not found


[Q]: Antipyrine was used as marker for oxidative stress .
[A]: not found


[Q]: Our data suggest that mild regular physical exercise favourably influences cholesterol distribution in serum lipoproteins in healthy middle aged men and may have beneficial effects on circulating metabolites of arachidonic acid .
[A]:
healthy middle aged men