CEREBRAL OXYGENATION/PERFUSION, CARDIOPULMONARY AND HEMODYNAMIC RESPONSES DURING MAXIMAL INCREMENTAL EXERCISE IN HEART TRANSPLANT RECIPIENTS VS. HEALTHY CONTROL SUBJECTS

Abstract

BACKGROUND: Accurate measurement of physical activity (PA) is necessary to monitor trends, assess relations with health and measure adherence to PA guidelines. While accelerometers provide accurate measures of PA they rely on validated cut-points to quantify time spent in light, moderate and vigorous intensities. Cut-points have largely been established using healthy populations; however, accelerometer output can differ based on cardiorespiratory fitness, suggesting that among individuals with compromised functioning such as those with coronary artery disease (CAD); these cut-points may lead to a misclassification of intensity. The objective of this study was to compare well-known and widely used cut-points (Sasaki) derived from healthy adults with those developed in a CAD population (Mark). METHODS: Two-hundred and thirty-one adults with CAD (mean SD: 63.7 9.2 years) wore an ActiGraph GT3X accelerometer for a minimum of 4 consecutive days and 10 hours/day. Daily time spent in moderate-to-vigorous PA (MVPA) was compared using two cut-point definitions: Mark (58.3 10.7 years, mean v