PURPOSE: The American College of Sports Medicine has stated that aerobic training needs to occur at a minimum threshold intensity of 50% VO(2max) for most healthy adults and at 40% VO(2max) for those with a very low initial @entity410 . Recently, the concept of @entity4962 reserve (%VO(2R), i.e., a percentage of the difference between maximum and resting @entity4962 ) has been introduced for prescribing exercise intensity. This analysis was designed to determine the threshold intensity for improving @entity410 expressed as %VO(2R) units. METHODS: Previous studies in healthy subjects (N = 18) that evaluated the results of training at low-to-moderate intensities (i.e., < or = 60% VO(2max)) were identified. The original studies described the intensity of exercise variously as %VO(2max), %HRR, %HR(max), or as a specific HR value. In each case, the intensity was translated into %VO(2R) units. RESULTS: Exercise training intensities below approximately 45% VO(2R) were consistently ineffective at increasing VO(2max) in studies that used subjects with mean initial VO(2max) values > 40 mL x @entity1009 ) x kg(-1). In studies using subjects with mean initial VO(2max) values < 40 mL x @entity1009 ) x kg(-1), no intensity was found to be ineffective. For this latter group of subjects, the lowest intensities examined were approximately 30% VO(2R). CONCLUSION: Although evidence for a threshold intensity was not strong, this analysis of training studies supports the use of 45% VO(2R) as a minimal effective training intensity for higher fit subjects and 30% VO(2R) for lower fit subjects.

VO(2) reserve and the minimal intensity for improving XXXX .

@entity1009 :: ('966', 'Gene') :: ['min(-1'] @entity410 :: ('MESH:D012640', 'Disease') :: ['fitness', 'cardiorespiratory fitness'] @entity4962 :: ('CHEBI:30046', 'Chemical') :: ['VO(2)']
@entity410 :: (MESH:D012640,Disease) :: ['cardiorespiratory fitness']
