scholarly journals Predicting metabolic rate during level and uphill outdoor walking using a low-cost GPS receiver

2016 ◽  
Vol 121 (2) ◽  
pp. 577-588 ◽  
Author(s):  
Pierre-Yves de Müllenheim ◽  
Rémy Dumond ◽  
Marie Gernigon ◽  
Guillaume Mahé ◽  
Audrey Lavenu ◽  
...  
Keyword(s):  
Metabolic Rate ◽  
Low Cost ◽  
Gps Receiver ◽  
Metabolic System ◽  
Map Projection ◽  
Metabolic Equivalents ◽  
Level Walking ◽  
Outdoor Walking ◽  
Speed Grade ◽  
Uphill Walking

The objective of this study was to assess the accuracy of using speed and grade data obtained from a low-cost global positioning system (GPS) receiver to estimate metabolic rate (MR) during level and uphill outdoor walking. Thirty young, healthy adults performed randomized outdoor walking for 6-min periods at 2.0, 3.5, and 5.0 km/h and on three different grades: 1) level walking, 2) uphill walking on a 3.7% mean grade, and 3) uphill walking on a 10.8% mean grade. The reference MR [metabolic equivalents (METs) and oxygen uptake (V̇o2)] values were obtained using a portable metabolic system. The speed and grade were obtained using a low-cost GPS receiver (1-Hz recording). The GPS grade (Δ altitude/distance walked) was calculated using both uncorrected GPS altitude data and GPS altitude data corrected with map projection software. The accuracy of predictions using reference speed and grade (actual[SPEED/GRADE]) data was high [ R2 = 0.85, root-mean-square error (RMSE) = 0.68 MET]. The accuracy decreased when GPS speed and uncorrected grade (GPS[UNCORRECTED]) data were used, although it remained substantial ( R2 = 0.66, RMSE = 1.00 MET). The accuracy was greatly improved when the GPS speed and corrected grade (GPS[CORRECTED]) data were used ( R2 = 0.82, RMSE = 0.79 MET). Published predictive equations for walking MR were also cross-validated using actual or GPS speed and grade data when appropriate. The prediction accuracy was very close when either actual[SPEED/GRADE] values or GPS[CORRECTED] values (for level and uphill combined) or GPS speed values (for level walking only) were used. These results offer promising research and clinical applications related to the assessment of energy expenditure during free-living walking.

Energy Expenditure in Brass and Woodwind Instrumentalists: The Effect of Body Posture

2011 ◽  
Vol 26 (4) ◽  
pp. 218-223 ◽  
Author(s):  
Vera AE Baadjou ◽  
Marjon DF van Eijsden-Besseling ◽  
Ans LW Samama-Polak ◽  
Rob JEM Smeets ◽  
Valéria Lima Passos ◽  
...  
Keyword(s):  
Energy Expenditure ◽  
Metabolic Rate ◽  
Exercise Therapy ◽  
Rest Energy Expenditure ◽  
Musical Instrument ◽  
Body Posture ◽  
Rest Energy ◽  
Metabolic Equivalents ◽  
Wind Instrument ◽  
Postural Exercise

Body posture appears to influence fatigue and musculoskeletal complaints in musicians. Our aim was to determine energy expenditure and to investigate whether energy expenditure is affected by body posture in brass and woodwind instrumentalists. METHODS: Eighteen musicians (10 women, 8 men; 6 brass, 12 woodwinds), with a mean age of 39 ± 14 years and mean body mass index of 23.8 ± 4.9 kg/m2, played their instruments for 30 minutes twice: once in nonoptimized body posture (posture A), and once in a posture according to the postural exercise therapy method Mensendieck (posture B). Patients were randomized to the order of postures in a crossover design AB/BA. Playing sessions were preceded and followed by 60 minutes of rest. Energy expenditure was measured in a respiration chamber with indirect calorimetry. Basal metabolic rate was measured with a ventilated hood. RESULTS: Mean metabolic equivalents (MET) for playing a wind instrument in the sitting position in a nonoptimized posture and posture according postural exercise therapy were 1.69 (SD 0.18) and 1.80 (SD 0.22), respectively. Percent change between resting metabolic rate and total energy expenditure while playing was 32% (95% CI 25–39%) in posture B and 23% (95% CI 17–30%) in posture A (p = 0.021). CONCLUSION: Average physical activity while playing a wind instrument approximates 1.8 MET. Our data show an association between energy expenditure and body posture while playing a brass or woodwind instrument: playing a musical instrument in a posture according to postural exercise therapy leads to higher energy expenditure as compared to a nonoptimized body posture. These results suggest that fatigue and the general feeling of lack of energy after playing a musical instrument are not related to actual higher energy expenditure.

The cold shoulder: free-ranging snowshoe hares maintain a low cost of living in cold climates

2009 ◽  
Vol 87 (10) ◽  
pp. 956-964 ◽  
Author(s):  
Michael J. Sheriff ◽  
J. R. Speakman ◽  
L. Kuchel ◽  
S. Boutin ◽  
M. M. Humphries
Keyword(s):  
Metabolic Rate ◽  
High Latitude ◽  
Low Cost ◽  
Resting Metabolic Rate ◽  
Mean Field ◽  
Resource Scarcity ◽  
Doubly Labelled Water ◽  
Snowshoe Hares ◽  
Free Ranging ◽  
The Relationship

The hypothesis that cold air temperatures (Ta) constrain the metabolic diversity of high-latitude endotherms is based on the observation among birds and mammals that mean field metabolic rate (FMR) increases, whereas the variability of FMR decreases, from the warm tropics to the cold poles. However, there is a paucity of FMR measurements from above 60° latitude and below 0 °C. We measured the daily energy expenditure of a high-latitude population of free-ranging snowshoe hares ( Lepus americanus Erxleben, 1777) in Yukon, Canada, in winter (Ta-mean = –16.4 °C) and in autumn (Ta-mean = 0.5 °C). Doubly labelled water measures of FMR were approximately 20% lower in winter than in autumn, and were a similar, low multiple of resting metabolic rate in both seasons (2.04 and 1.94, respectively). The mass-corrected FMR of snowshoe hares in winter was only half the value predicted by extrapolating the relationship between FMR and Ta > 0 to –16.4 °C. These results contribute to an emerging pattern of a reversal in the relationship between FMR and Ta in free-ranging mammals from negative above 0 °C to positive below 0 °C. We refer to the positive, low Ta portion of this relationship as the cold shoulder, and suggest that it may reflect the general necessity for free-ranging mammals to use behavioural and (or) physiological means to conserve energy during long winters when cold conditions coincide with resource scarcity.

A Low-Cost GPS Receiver for Land Navigation

Navigation ◽  
1982 ◽  
Vol 29 (3) ◽  
pp. 204-220
Author(s):  
KAI P. YIU ◽  
RICHARD CRAWFORD ◽  
RALPH ESCHENBACH
Keyword(s):  
Low Cost ◽  
Gps Receiver

Reducing the metabolic rate of walking and running with a versatile, portable exosuit

Science ◽  
2019 ◽  
Vol 365 (6454) ◽  
pp. 668-672 ◽  
Author(s):  
Jinsoo Kim ◽  
Giuk Lee ◽  
Roman Heimgartner ◽  
Dheepak Arumukhom Revi ◽  
Nikos Karavas ◽  
...  
Keyword(s):  
Potential Energy ◽  
Metabolic Rate ◽  
Athletic Performance ◽  
Center Of Mass ◽  
Treadmill Walking ◽  
Metabolic Rates ◽  
Hip Extension ◽  
Uphill Walking

Walking and running have fundamentally different biomechanics, which makes developing devices that assist both gaits challenging. We show that a portable exosuit that assists hip extension can reduce the metabolic rate of treadmill walking at 1.5 meters per second by 9.3% and that of running at 2.5 meters per second by 4.0% compared with locomotion without the exosuit. These reduction magnitudes are comparable to the effects of taking off 7.4 and 5.7 kilograms during walking and running, respectively, and are in a range that has shown meaningful athletic performance changes. The exosuit automatically switches between actuation profiles for both gaits, on the basis of estimated potential energy fluctuations of the wearer’s center of mass. Single-participant experiments show that it is possible to reduce metabolic rates of different running speeds and uphill walking, further demonstrating the exosuit’s versatility.

A Navigation Algorithm for the Low-Cost GPS Receiver

Navigation ◽  
1978 ◽  
Vol 25 (2) ◽  
pp. 258-264 ◽  
Author(s):  
P. S. NOE ◽  
K. A. MYERS ◽  
T. K. WU
Keyword(s):  
Low Cost ◽  
Gps Receiver ◽  
Navigation Algorithm
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