Using GPS, accelerometry and heart rate to predict outdoor graded walking energy expenditure.

OBJECTIVES: To determine the best method and combination of methods among global positioning system (GPS), accelerometry, and heart rate (HR) for estimating energy expenditure (EE) during level and graded outdoor walking. DESIGN: Thirty adults completed 6-min outdoor walks at speeds of 2.0, 3.5, and 5.0kmh-1 during three randomized outdoor walking sessions: one level walking session and two graded (uphill and downhill) walking sessions on a 3.4% and a 10.4% grade. EE was measured using a portable metabolic system (K4b2). Participants wore a GlobalSat® DG100 GPS receiver, an ActiGraph™ wGT3X+ accelerometer, and a Polar® HR monitor. Linear mixed models (LMMs) were tested for EE predictions based on GPS speed and grade, accelerometer counts or HR-related parameters (alone and combined). Root-mean-square error (RMSE) was used to determine the accuracy of the models. Published speed/grade-, count-, and HR-based equations were also cross-validated. RESULTS: According to the LMMs, GPS was as accurate as accelerometry (RMSE=0.89-0.90kcalmin-1) and more accurate than HR (RMSE=1.20kcalmin-1) for estimating EE during level walking; GPS was the most accurate method for estimating EE during both level and uphill (RMSE=1.34kcalmin-1)/downhill (RMSE=0.84kcalmin-1) walking; combining methods did not increase the accuracy reached using GPS (or accelerometry for level walking). The cross-validation results were in accordance with the LMMs, except for downhill walking. CONCLUSIONS: Our study provides useful information regarding the best method(s) for estimating EE with appropriate equations during level and graded outdoor walking.

Training to Perform Ankle-Brachial Index: Systematic Review and Perspectives to Improve Teaching and Learning.

OBJECTIVE: To conduct a systematic review focusing on the impact of training programs on ankle-brachial index (ABI) performance by medical students, doctors and primary care providers. Lower extremity peripheral artery disease (PAD) is a highly prevalent disease affecting ∼202 million people worldwide. ABI is an essential component of medical education because of its ability to diagnose PAD, and as it is a powerful prognostic marker for overall and cardiovascular related mortality. METHODS: A systematic search was conducted (up to May 2015) using Medline, Embase, and Web of Science databases. RESULTS: Five studies have addressed the impact of a training program on ABI performance by either medical students, doctors or primary care providers. All were assigned a low GRADE system quality. The components of the training vary greatly either in substance (what was taught) or in form (duration of the training, and type of support which was used). No consistency was found in the outcome measures. CONCLUSION: According to this systematic review, only few studies, with a low quality rating, have addressed which training program should be performed to provide the best way of teaching how to perform ABI. Future high quality researches are required to define objectively the best training program to facilitate ABI teaching and learning.

Clinical Interest of Ambulatory Assessment of Physical Activity and Walking Capacity in Peripheral Artery Disease.

The purpose of the present review was to provide, for the first time, a comprehensive analysis and synthesis of the available studies that highlighted the clinical interest of the ambulatory assessment of either physical activity (PA) or walking capacity in patients with lower extremity peripheral artery disease (PAD). We identified 96 related articles published up to March 2015 through a computer-assisted search of the MEDLINE, EMBASE, and Web of Science databases. Ambulatory-measured PA or related energy expenditure (EE) in PAD patients was performed in 87 of the 96 included studies. The main clinical interests of these measurements were (a) the assessment of PA/EE pattern; (b) the characterization of walking pattern; and (c) the control of training load during home-based walking programs. Ambulatory-measured walking capacity was performed in the remaining studies, using either Global Positioning System receivers or the Peripheral Arterial Disease Holter Control device. Highlighted clinical interests were (a) the assessment of community-based walking capacity; (b) the use of new outcomes to characterize walking capacity, besides the conventional absolute claudication distance; and (c) the association with the patient's self-perception of walking capacity. This review also provides for the clinicians step-by-step recommendations to specifically assess PA or walking capacity in PAD patients.