Carbohydrate and fat oxidation in persons with lower limb amputation during walking with different speeds

Background: Studies suggest that the energy expenditure of healthy persons (control) during walking with the preferred walking speed in steady-state conditions is dominated by fat oxidation. Conversely, carbohydrate and fat oxidation during walking is little investigated in transfemoral amputees. Objectives: To investigate carbohydrate and fat oxidation, energy cost of walking, and percent utilization of maximal aerobic capacity [Formula: see text]during walking. Study design: Eight transfemoral amputees and controls walked with their preferred walking speed and speeds 12.5% and 25% slower and faster than their preferred walking speed. Methods: Energy expenditure and fuel utilization were measured using a portable metabolic analyzer. Metabolic values are means ± standard deviation. Results: For transfemoral amputees (37.0 ± 10.9 years) and controls (39.0 ± 12.3 years), fat utilization at the preferred walking speed was 44.8% ± 7.2% and 45.0% ± 7.2% of the total energy expenditure, respectively. The preferred walking speed of the transfemoral amputees and controls was close to a metabolic cross-over speed, which is the speed where carbohydrate utilization increases steeply and fat utilization decreases. When walking fast, at 90 m min−1 (preferred walking speed plus 25%), transfemoral amputees utilized 70.7% ± 5.6% of their [Formula: see text], while the controls utilized 30.9% ± 4.5% ( p < 0.001) at the matching speed (control preferred walking speed). At 90 m min−1, carbohydrate utilization was 78% ± 4.7% and 55.2% ± 7.2% of the total energy expenditure for the transfemoral amputees and controls, respectively ( p < 0.01). Compared to the control, energy cost of walking was higher for the transfemoral amputees at all speeds (all comparisons; p < 0.001). Conclusion: At the preferred walking speed, carbohydrate, not fat, dominates energy expenditure of both transfemoral amputees and controls. For the transfemoral amputees, consequences of fast walking are very high [Formula: see text] utilization and rate of carbohydrate oxidation. Clinical relevance Research on the relationships between physical effort and fuel partitioning during ambulation could provide important insights for exercise-rehabilitation programs for lower limb amputees (LLA). Regular endurance exercise will improve maximal aerobic capacity and enable LLA to walk faster and at the same time expend less energy and improve fat utilization.

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The energy expenditure of cattle and buffaloes walking and working in different soil conditions

The Journal of Agricultural Science ◽

10.1017/s0021859696003929 ◽

1997 ◽

Vol 128 (1) ◽

pp. 95-103 ◽

Cited By ~ 20

Author(s):

J. T. DIJKMAN ◽

P. R. LAWRENCE

Keyword(s):

Energy Expenditure ◽

Energy Cost ◽

Walking Speed ◽

Bos Taurus ◽

Bos Indicus ◽

Ground Surface ◽

Mechanical Efficiency ◽

Open Circuit ◽

Soil Conditions ◽

Energy Cost Of Walking

At the Centre for Tropical Veterinary Medicine, Scotland, during the summer months of 1987, two adult water buffaloes, two Brahman cattle and two Brahman × Friesian steers walked round a circular track on concrete or through 300 mm deep mud. Average walking speed (m/s) when unloaded, or average walking speed (m/s) when pulling 324 N, energy for walking (J/m/kg) and net mechanical efficiency (%) were 1·05 and 0·81 (P < 0·01), 1·03 and 0·80 (P < 0·001), 1·49 and 3·34 (P < 0·001) and 31·0 and 31·8 for concrete and mud respectively. Energy values were calculated from gaseous exchange measured with an open circuit system.In Central Nigeria, from September 1991 to May 1992, the energy expenditure of eight Bunaji (White Fulani) bulls was monitored using portable oxygen measuring equipment (modified ‘Oxylog’) when walking, ploughing and harrowing on six soil surfaces ranging from hard, smooth earth to ploughed, waterlogged clay. Average walking speeds (m/s), pulling speeds (m/s) and energy cost of walking (J/m/kg) varied from 0·97 to 0·65, 0·55 to 0·47 and 1·47 to 8·58 respectively. Net mechanical efficiency averaged 31·4% and was unaffected by ground surface.The energy cost of walking for the Bos indicus cattle on smooth ground (1·47 J/m/kg) in this trial was less than that previously reported for Bos taurus (1·80 J/m/kg) and the reported average value for cattle (Bos indicus and Bos taurus) on treadmills (2·09 J/m/kg). The implications for practical agriculture of the higher levels of energy expenditure for walking in muddy conditions are discussed.

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Energy cost of walking and gait instability in healthy 65- and 80-yr-olds

Journal of Applied Physiology ◽

10.1152/japplphysiol.01106.2002 ◽

2003 ◽

Vol 95 (6) ◽

pp. 2248-2256 ◽

Cited By ~ 124

Author(s):

Davide Malatesta ◽

David Simar ◽

Yves Dauvilliers ◽

Robin Candau ◽

Fabio Borrani ◽

...

Keyword(s):

Energy Expenditure ◽

Energy Cost ◽

Walking Speed ◽

Time Variability ◽

Elderly Subjects ◽

Stride Time ◽

Healthy Elderly ◽

Walking Speeds ◽

Energy Cost Of Walking ◽

Healthy Elderly Subjects

This study tested whether the lower economy of walking in healthy elderly subjects is due to greater gait instability. We compared the energy cost of walking and gait instability (assessed by stride to stride changes in the stride time) in octogenarians (G80, n = 10), 65-yr-olds (G65, n = 10), and young controls (G25, n = 10) walking on a treadmill at six different speeds. The energy cost of walking was higher for G80 than for G25 across the different walking speeds ( P < 0.05). Stride time variability at preferred walking speed was significantly greater in G80 (2.31 ± 0.68%) and G65 (1.93 ± 0.39%) compared with G25 (1.40 ± 0.30%; P < 0.05). There was no significant correlation between gait instability and energy cost of walking at preferred walking speed. These findings demonstrated greater energy expenditure in healthy elderly subjects while walking and increased gait instability. However, no relationship was noted between these two variables. The increase in energy cost is probably multifactorial, and our results suggest that gait instability is probably not the main contributing factor in this population. We thus concluded that other mechanisms, such as the energy expenditure associated with walking movements and related to mechanical work, or neuromuscular factors, are more likely involved in the higher cost of walking in elderly people.

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β-Adrenergically Stimulated Fat Oxidation Is Diminished in Middle-Aged Compared to Young Subjects*

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/jcem.84.10.6043 ◽

1999 ◽

Vol 84 (10) ◽

pp. 3764-3769

Author(s):

E. E. Blaak ◽

M. A. van Baak ◽

W. H. M. Saris

Keyword(s):

Skeletal Muscle ◽

Energy Expenditure ◽

Total Energy ◽

Fat Oxidation ◽

Substrate Utilization ◽

Total Energy Expenditure ◽

Adrenergic Stimulation ◽

Middle Aged ◽

Older Subjects ◽

Young Subjects

Abstract The effect of aging on β-adrenergically mediated substrate utilization was investigated in nine young (25.2 ± 1.7 yr old) and eight older males (52.9 ± 2.1 yr old), matched for body weight and body composition. In a first experiment, the nonselectiveβ -agonist isoprenaline (ISO) was infused in increasing standardized doses, and during each infusion period energy expenditure and substrate utilization were determined by indirect calorimetry. In a second experiment, forearm skeletal muscle metabolism was studied during a standardized infusion dose of ISO (19 ng/kg fat-free mass·min). During β-adrenergic stimulation there was an increased carbohydrate oxidation (at an ISO infusion dose of 24 ng/kg fat-free mass·min, 31% vs. 21% of total energy expenditure; P < 0.05) and a decreased fat oxidation (51 vs. 62 of total energy expenditure; P < 0.05) in older compared to young subjects. Skeletal muscle lactate release significantly increased in the older subjects (from −175 ± 32 to −366 ± 66 nmol/100 mL forearm tissue·min), whereas there was no change in young subjects (from− 32 ± 21 to 23 ± 57 nmol/100 mL forearm tissue·min; interaction group × ISO, P < 0.01). Additionally, there was a tendency toward a blunted ISO-induced increase in nonesterified fatty acid uptake in the older subjects (interaction group × ISO, P = 0.062). Thus, middle-aged subjects have a blunted ability to oxidize fat during β-adrenergic stimulation compared to young subjects. This diminished fat oxidation may be an important etiological factor in the age-related increase in body fatness and obesity by favoring fat storage above oxidation.

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WHICH IS THE BEST WAY TO PERFORM THE PHYSIOLOGICAL COST INDEX IN ACTIVE INDIVIDUALS WITH UNILATERAL TRANS-TIBIAL AMPUTATION?

Canadian Prosthetics & Orthotics Journal ◽

10.33137/cpoj.v2i1.32953 ◽

2019 ◽

Author(s):

Stefano Brunelli ◽

Andrea Sancesario ◽

Marco Iosa ◽

Anna Sofia Delussu ◽

Noemi Gentileschi ◽

...

Keyword(s):

Heart Rate ◽

Oxygen Consumption ◽

Energy Expenditure ◽

Energy Cost ◽

Limb Amputation ◽

Alternative Measure ◽

Cost Index ◽

Physiological Cost ◽

Fitness Training ◽

Energy Cost Of Walking

BACKGROUND: Physiological Cost Index (PCI) is a simple method used to estimate energy expenditure during walking. It is based on a ratio between heart rate and self-selected walking speed. Previous studies reported that PCI is reliable in individuals with lower limb amputation but only if there is an important walking impairment. No previous studies have investigated the correlation of PCI with the Energy Cost Walking (ECW) in active individuals with traumatic unilateral trans-tibial amputation, considering that this particular category of amputees has an ECW quite similar to healthy individual without lower limb amputation. Moreover, it is important to determine if PCI is also correlated to ECW in the treadmill test so as to have an alternative to over-ground test. OBJECTIVES: The aim of this study was to evaluate the correlation between PCI and ECW in active individuals with traumatic trans-tibial amputation in different walking conditions. The secondary aim was to evaluate if this correlation permits to determine ECW from PCI values. METHODOLOGY: Ninety traumatic amputees were enrolled. Metabolic data, heart rate and walking speed for the calculation of ECW and for PCI were computed over-ground and on a treadmill with 0% and 12% slopes during a 6-minute walking test. FINDINGS: There is a significant correlation between ECW and PCI walking over-ground (p=0.003; R2=0.10) and on treadmill with 12% slopes (p=0.001; R2=0.11) but there is only a poor to moderate correlation around the trendline. No significant correlation was found walking on treadmill with 0% slope. The Bland-Altman plot analysis suggests that is not possible to evaluate ECW directly from PCI. CONCLUSIONS: PCI is a reliable alternative measure of energy expenditure during walking in active individuals with trans-tibial amputation when performing over-ground or at high intensity effort on treadmill. PCI is therefore useful only for monitoring a within subject assessment. LAYMAN’S ABSTRACT The knowledge of the energy cost of walking in disabled people is important to improve strategies of rehabilitation or fitness training and to develop new prosthetic and orthotic components. The “gold standard” for the evaluation of the energy cost of walking is the oxygen consumption measurement with a metabolimeter, but the testing procedure is expensive and time consuming, hardly practicable in many rehabilitation centers. The Physiological Cost Index (PCI) is an indirect tool that evaluates the oxygen consumption during walking. PCI considers heart rate during walking, in relation to the speed, as an indicator of energy expenditure. The formula is “walking heart rate – resting heart rate /speed”. PCI is widely used in literature but there is not a solid evidence of a direct correlation between PCI and energy cost of walking. In particular, for individuals with unilateral trans-tibial amputation without comorbidities, no previous studies have been conducted about this correlation. It has to be noticed that individuals with unilateral trans-tibial amputation have an energy cost of walking quite similar to healthy people. Previous studies reported that in healthy people such correlation does not exist. For this reason, the aim of this study was to evaluate if and in which walking condition a linear correlation exists between PCI and Energy Cost Walking in individuals with unilateral trans-tibial amputation. Oxygen consumption measurement with a metabolimeter and PCI were computed over-ground and on a treadmill with 0% and 12% slopes during a 6-minute walking test in 90 participants. We have found that PCI is an alternative measure of energy cost of walking when performing over-ground or with high intensity effort on treadmill (12% slope). These findings could be useful when PCI is used for monitoring a fitness training or for evaluation tests. Article PDF Link: https://jps.library.utoronto.ca/index.php/cpoj/article/view/32953/25717 How to Cite: Brunelli S, Sancesario A, Iosa M, Delussu A.S, Gentileschi N, Bonanni C, Foti C, Traballesi M. Which is the best way to perform the Physiological Cost Index in active individuals with unilateral trans-tibial amputation? Canadian Prosthetics & Orthotics Journal. Volume2, Issue1, No.5, 2019. https://doi.org/10.33137/cpoj.v2i1.32953. CORRESPONDING AUTHOR: Dr. Stefano Brunelli,Fondazione Santa Lucia, IRCCS, Via Ardeatina 306, 00179 Rome, Italy.ORCID: https://orcid.org/0000-0002-5986-1564Tel. +39 0651501844; Fax +39 0651501919E-MAIL: [email protected]

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The relationship between relative aerobic load, energy cost, and speed of walking in individuals post-stroke

10.1101/2021.03.22.21253569 ◽

2021 ◽

Author(s):

Ilse Johanna Blokland ◽

Arianne S Gravesteijn ◽

Mathijs C Busse ◽

Floor P Groot ◽

Coen AM van Bennekom ◽

...

Keyword(s):

Energy Expenditure ◽

Aerobic Capacity ◽

Energy Cost ◽

Walking Speed ◽

Ventilatory Threshold ◽

Research Question ◽

Walking Ability ◽

Cross Sectional ◽

Relative Load ◽

Post Stroke

Background: Individuals post-stroke walk slower than their able-bodied peers, which limits participation. This might be attributed to neurological impairments, but could also be caused by a mismatch between aerobic capacity and aerobic load of walking. Research question: What is the potential impact of aerobic capacity and aerobic load of walking on walking ability post-stroke? Methods: In a cross-sectional study, forty individuals post-stroke (more impaired N=21; preferred walking speed (PWS)<0.8m/s, less impaired N=19), and 15 able-bodied individuals performed five, 5-minute treadmill walking trials at 70%, 85%, 100%, 115% and 130% of PWS. Energy expenditure (mlO2/kg/min) and energy cost (mlO2/kg/m) were derived from oxygen uptake (VO2). Relative load was defined as energy expenditure divided by peak aerobic capacity (%VO2peak) and by VO2 at ventilatory threshold (%VO2-VT). Relative load and energy cost at PWS were compared between groups with one-way ANOVAs. The effect of speed on these parameters was modeled with GEE. Results: Both more and less impaired individuals post-stroke showed lower PWS than able-bodied controls (0.44[0.19-0.76] and 1.04[0.81-1.43] vs 1.36[0.89-1.53] m/s) and higher relative load at PWS (50.2±14.4 and 51.7±16.8 vs 36.2±7.6 %VO2 peak and 101.9±20.5 and 97.0±27.3 vs 64.9±13.8 %VO2-VT). No differences in relative load were found between stroke groups. Energy cost at PWS of more impaired (0.30[.19-1.03] mlO2/kg/m) was higher than less-impaired (0.19[0.10-0.24] mlO2/kg/m) and able-bodied (0.15[0.13-0.18] mlO2/kg/m). For post-stroke individuals, increasing walking speed above PWS decreased energy cost, but resulted in a relative load above endurance threshold. Significance: Individuals post-stroke seem to reduce walking speed to prevent unsustainably high relative aerobic loads at the expense of reduced economy. When aiming to improve walking ability in individuals post-stroke, it is important to consider training aerobic capacity.

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Direct measurement of the energy expenditure of physical activity in preterm infants

Journal of Applied Physiology ◽

10.1152/jappl.1998.85.1.223 ◽

1998 ◽

Vol 85 (1) ◽

pp. 223-230 ◽

Cited By ~ 30

Author(s):

Patti J. Thureen ◽

Robert E. Phillips ◽

Karen A. Baron ◽

Mark P. DeMarie ◽

William W. Hay

Keyword(s):

Physical Activity ◽

Energy Expenditure ◽

Preterm Infants ◽

Direct Measurement ◽

Muscle Activity ◽

Energy Cost ◽

Force Plate ◽

Total Energy Expenditure ◽

Active Sleep ◽

Quiet Sleep

The energy cost of physical activity (EEA) has been estimated to account for 5–17% of total energy expenditure (TEE) in neonates. To directly measure EEA, a force plate was developed and validated to measure work outputs ranging from 0.3 to 40 kcal ⋅ kg−1 ⋅ day−1. By use of this force plate plus indirect calorimetry, TEE and EEA were measured and correlated with five activity states in 24 infants with gestational age of 31.6 ± 0.5 (SE) wk and postnatal age of 24.8 ± 3.7 days. TEE and EEA were 69.2 ± 1.5 and 2.4 ± 0.2 kcal ⋅ kg−1 ⋅ day−1, respectively. EEA per state was 0.5 ± 0.0 (quiet sleep), 2.4 ± 0.2 (active sleep), 2.8 ± 0.4 (quiet awake), 7.5 ± 0.8 (active awake), and 15.1 ± 2.3 (crying) kcal ⋅ kg−1 ⋅ day−1. This provides the first direct measurement of the contribution of physical activity to TEE in preterm infants and will enable measurement of caloric expenditure from muscle activity in various disease conditions and development of nursing strategies to minimize unnecessary energy losses.

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The CAT-CAM socket and quadrilateral socket: A comparison of energy cost during ambulation

Prosthetics and Orthotics International ◽

10.3109/03093649309164363 ◽

1993 ◽

Vol 17 (2) ◽

pp. 95-100 ◽

Cited By ~ 25

Author(s):

R. S. Gailey ◽

D. Lawrence ◽

C. Burditt ◽

P. Spyropoulos ◽

C. Newell ◽

...

Keyword(s):

Energy Expenditure ◽

Energy Cost ◽

Randomized Trials ◽

Walking Speed ◽

Vascular Pathology ◽

Control Group ◽

Alignment Method ◽

Normal Walking ◽

Post Hoc ◽

Healthy Males

Twenty unilateral trans-femoral amputees fitted with either the Contoured Adducted Trochanteric-Controlled Alignment Method (CAT-CAM) socket (n=10) or the quadrilateral (QUAD) socket (n=10), and a “non-amputee” control group (n=10) participated in the study. Subjects meeting the following criteria were studied: healthy males between the ages of 18 and 55 years, amputation due to non-vascular pathology, an unaffected sound limb, at least six months use of the test prosthesis, and a minimal stump length of 15 cm. Subjects ambulated in two randomized trials separated by 20 minutes of rest at 2 assigned speeds: a pace reflecting normal walking speed (97 m/min=2.5 mph) or a slower speed (48.5 m/min=1.25 mph). Heart rate (HR) and Oxygen uptake (VO2) measured during steady state walking were analyzed via two-way ANOVA. Differences among means were further analyzed using Tukey post hoc and simple effects tests. Significant differences were observed between the control group and CAT-CAM subjects with respect to VO2 (p < 0.05) and HR (p < 0.01) at the slower speed. The control group and subjects using the QUAD socket also differed with respect to VO2 (p < 0.01) and HR (p < 0.01) at the slower pace. Faster pace required more energy expenditure (p < 0.01) and produced higher HR (p < 0.01) than slower speeds. At faster pace, a significantly higher energy expenditure in the QUAD than the CAT-CAM group was observed (p<0.01). It is concluded that ambulating at normal pace using the CAT-CAM socket design uses less energy than when using a QUAD socket design.

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