The Effect of Obesity Class on the Energetics and Mechanics of Walking

Abstract

Higher mass-normalized net energy cost of walking (NetCw/kg) and mechanical pendular recovery are observed in obese compared to lean adults. This study aimed to investigate the effect of different classes of obesity on the energetics and mechanics of walking and to explore the relationships between body mass, NetCw/kg and gait mechanics by using principal component analysis (PCA). NetCw/kg and gait mechanics were computed in severely obese (SOG; n = 18, BMI = 40.1 ± 4.4 kg·m−2), moderately obese (MOG; n = 17, BMI = 32.2 ± 1.5 kg·m−2) and normal-weight (NWG; n = 13, BMI = 22.0 ± 1.5 kg·m−2) adults during five walking trials (0.56, 0.83, 1.11, 1.39, 1.67 m·s−1) on an instrumented treadmill. NetCw/kg was significantly higher in SOG compared to NWG (p = 0.019), with no significant difference between SOG and MOG (p = 0.14), nor between MOG and NWG (p = 0.27). Recovery was significantly higher in SOG than in NWG (p = 0.028), with no significant difference between SOG and MOG (p = 0.13), nor between MOG and NWG (p = 0.35). PCA models explained between 17.0% and 44.2% of the data variance. This study showed that: (1) obesity class influences the gait energetics and mechanics; (2) PCA was able to identify two components, showing that the obesity class is associated with lower walking efficiency and better pendulum-like characteristics.

Treadmill walking economy is not affected by body fat and body mass index in adults

“…The data displayed in Figure 1 Published data on the impact of BMI or body fat on the metabolic cost of walking are inconsistent. A higher net Cw or metabolic rate in adults with obesity has been reported in some studies (Browning et al, 2006;Browning & Kram, 2005;Fernandez Menendez et al, 2020;Primavesi et al, 2021) but not others (Bode et al, 2020;Browning et al, 2013; , 2009). One study actually reported a lower relative VȮ 2 (mL/kg/min) during walking in females with severe obesity compared to relatively lean females (Farrell et al, 1985).…”

“…In the earlier study (Fernandez Menendez et al, 2019), net Cw was not different between groups with different mean BMI (33.8 kg/m 2 vs. 21.9 kg/ m 2 ) at the four slowest speeds, but was only significantly greater in the higher-BMI group at the fastest walking speed (1.67 m/s). A third study (Primavesi et al, 2021) from this group, that used pooled data from the first two studies along with additional participants, found that net Cw in individuals with grade II or III obesity (BMI ≥ 35 m/ kg 2 ; mean = 40.1 m/kg 2 ) was 15% higher than net Cw in individuals with a BMI in the normal-weight range (BMI 18.5-24.9 kg/m 2 ; mean = 22.0 m/kg 2 ) but nonsignificantly 6% higher than individuals with grade I obesity (BMI 30-34.9 m/kg 2 ; mean = 32.2 kg/m 2 ). The authors posited that the degree of obesity influences net Cw.…”

“…Overall, sample sizes were relatively small. Five of the 12 studies cited above had ≤10 participants in one or more of their BMI-defined groups (Bode et al, 2020;Browning & Kram, 2005;Farrell et al, 1985;Lafortuna et al, 2008;Peyrot et al, 2009), and only four of the studies had >15 participants in any of their BMI-defined groups (Browning et al, 2006(Browning et al, , 2013Peyrot et al, 2009;Primavesi et al, 2021). Due to the large individual variability in energy cost of walking (Gaesser et al, 2018), and the wide range in mean net Cw (1.71 to 2.45 J/kg/m) reported in the literature (Rubenson et al, 2007), a small sample size could complicate the interpretation and comparison of results and limit the generalizability of the findings.…”

“…Since individuals with obesity have a lower relative maximum oxygen uptake (VȮ 2max ) (Browning et al, 2006(Browning et al, , 2013Farrell et al, 1985;LeCheminant et al, 2009), exercise at a fixed walking speed elicits a higher percentage of their VȮ 2max , which, if above the lactate threshold, might evoke a slow component of VȮ 2 that would result in higher Cw. Finally, body mass-adjusted standing metabolic rate (SMR) is also lower in individuals with obesity (Browning et al, 2006(Browning et al, , 2013Browning & Kram, 2005;Fernandez Menendez et al, 2020;Lafortuna et al, 2008;Primavesi et al, 2021). This can affect the interpretation of the data on the metabolic cost of walking (Browning et al, 2013;Browning & Kram, 2005;Fernandez Menendez et al, 2019).…”

Pendular mechanism determinants and elastic energy usage during walking of obese and non‐obese children

“…Nine obese (OB) (six female, 8.7 ± 0.5 years, 1.38 ± 0.04 m, 44.4 ± 6.3 kg, and 24.1 ± 3.50 kg/m 2 ) and eight non-obese (Non-OB) (four female, 7.4 ± 0.7 years, 1.31 ± 0.08 m, 26.6 ± 2.1 kg and 16.4 ± 1.40 kg/m 2 ) children took part. The sample size of eight participants per group was calculated based on the recovery data of the study byPrimavesi et al (2021), using α of 0.05 and power of 0.90. The participants were chosen by convenience.…”