“…Regarding the level of evidence for the comparator instrument, ten 35,55,28,62,66,71,73,74,78 analyses (23%) used a comparator instrument classified as level 1, eight 46,47,61,62,65---67,81 analyses (18%) as level 2 and twenty-six 32---34,39,41,43,44,48---51,54,57,59,60,63,67---70,72,75---77,79,80 analyses (59%) as level 3. Thirty-five analyses reported the construct validity using objective measures as comparator, such as accelerometer 35,45---47,28,61,65---67,71,73,74,81 (n = 16), pedometer 33,43,44,50,57,69,70,76,79 (n = 9), frequency meter 51,60 (n = 2), doubly labeled water 78 (n = 1) and VO 2 max 41,48,49,51,70,75,80 (n = 7). For the criterion validity, all studies received an indeterminate (?)…”