Erreka Gil-Rey1,2, Sara Maldonado-Martín2, Natalia Palacios-Samper1, Esteban M Gorostiaga1. 1. a Studies , Research and Sport Medicine Centre (CEIMD), Government of Navarre , Pamplona , Spain. 2. b Deparment of Physical Education and Sport, Faculty of Education and Sport, Physical Activity and Sport Sciences Section , University of the Basque Country (UPV/EHU) , Vitoria-Gasteiz , Basque Country, Spain.
Abstract
OBJECTIVES: To investigate how objectively measured physical activity (PA) levels differ according to absolute moderate intensity recommendation (3-6 METs) and relative to individual lactate thresholds (LT1 and LT2), and to verify if high-fit women record higher PA levels compared to women with lower aerobic fitness. METHODS: Seventy-five postmenopausal women performed an incremental exercise test and several constant-velocity tests wearing an accelerometer to identify the activity counts (ct min-1) corresponding to LT1 and LT2. Individual linear regression determined activity counts cut-points for each intensity: (1) sedentary (<200 ct min-1), (2) light (from 200 ct min-1 to ct min-1 at LT1), (3) moderate (ct min-1 between LT1 and LT2) and (4) vigorous (ct min-1 > LT2). Participants then wore an accelerometer during a week to measure the time spent at each PA intensity level. RESULTS: According to absolute intensity categorisation, high-fit postmenopausal women recorded twice as much time at moderate-to-vigorous PA (MVPA) (P < 0.01) than low-fit women. However, when PA intensity was calculated relative to individual lactate thresholds, MVPA was significantly reduced by half (P < 0.01) and the data revealed no differences (P = 0.62) between groups (∼20 min day-1 at MVPA). CONCLUSIONS: Accelerometer cut-points derived from absolute moderate-intensity recommendations overestimated MVPA. Similar time at MVPA was recorded by high- and low-fit postmenopausal women when the cut-points were tailored to individual lactate thresholds. A more accurate estimation of PA behaviour could be provided with the use of individually tailored accelerometer cut-points.
OBJECTIVES: To investigate how objectively measured physical activity (PA) levels differ according to absolute moderate intensity recommendation (3-6 METs) and relative to individual lactate thresholds (LT1 and LT2), and to verify if high-fit women record higher PA levels compared to women with lower aerobic fitness. METHODS: Seventy-five postmenopausal women performed an incremental exercise test and several constant-velocity tests wearing an accelerometer to identify the activity counts (ct min-1) corresponding to LT1 and LT2. Individual linear regression determined activity counts cut-points for each intensity: (1) sedentary (<200 ct min-1), (2) light (from 200 ct min-1 to ct min-1 at LT1), (3) moderate (ct min-1 between LT1 and LT2) and (4) vigorous (ct min-1 > LT2). Participants then wore an accelerometer during a week to measure the time spent at each PA intensity level. RESULTS: According to absolute intensity categorisation, high-fit postmenopausal women recorded twice as much time at moderate-to-vigorous PA (MVPA) (P < 0.01) than low-fit women. However, when PA intensity was calculated relative to individual lactate thresholds, MVPA was significantly reduced by half (P < 0.01) and the data revealed no differences (P = 0.62) between groups (∼20 min day-1 at MVPA). CONCLUSIONS: Accelerometer cut-points derived from absolute moderate-intensity recommendations overestimated MVPA. Similar time at MVPA was recorded by high- and low-fit postmenopausal women when the cut-points were tailored to individual lactate thresholds. A more accurate estimation of PA behaviour could be provided with the use of individually tailored accelerometer cut-points.
Authors: Philipp Birnbaumer; Pavel Dietz; Estelle Dorothy Watson; Gudani Mukoma; Alexander Müller; Matteo Christian Sattler; Johannes Jaunig; Mireille Nicoline Maria van Poppel; Peter Hofmann Journal: Int J Environ Res Public Health Date: 2020-08-05 Impact factor: 3.390