Statistical analyses
FM
SECONDARY
We assessed the normal distribution of the data with visual inspection and Shapiro–Wilk’s test. Differences between groups (FM and controls) were assessed using unpaired t-tests for normal variables and Mann–Whitney U test for non-normal variables. As not all participants reached maximal effort, we analyzed separately the peak exercise responses after excluding these participants.We used repeated measures ANOVA, where work rate was a within-subject factor and group a between-subject factor, for the analysis of cardiorespiratory responses during exercise. We then performed a separate MANOVA to further identify the work rates where between-group differences exist.We analyzed ΔWe used Spearman correlations to explore the relations between work rate, HR, We conducted a secondary analysis with the FM group. We identified a subgroup of participants who could not reach maximal effort (the ‘submaximal’ group) and they were compared with those who reached maximal effort (the ‘maximal’ group).All normal data are reported as mean ± SD, non-normal data as median [interquartile range], and categorical data as count (%), unless otherwise stated. Alpha was set to 0.05. The 