Knee extension strength in obese and nonobese male adolescents

Abstract

The aim of the present study was to compare "absolute" and "relative" knee extension strength between obese and nonobese adolescents. Ten nonobese and 12 severely obese adolescent boys of similar chronological age, maturity status, and height were compared. Total body and regional soft tissue composition were determined using dual-energy X-ray absorptiometry (DXA). Knee extensors maximum voluntary contraction (MVC) torque was measured using an isometric dynamometer at a knee angle of 60° (0° is full extension). Absolute MVC torque was significantly higher in obese adolescents than in controls. However, although MVC torque expressed per unit of body mass was found to be significantly lower in obese adolescent boys, no significant difference in MVC torque was found between groups when normalized to fat-free mass. Conversely, when correcting for thigh lean mass and estimated thigh muscle mass, MVC torque was significantly higher in the obese group (17.9% and 22.2%, respectively; P <0.05). To conclude, our sample of obese adolescent boys had higher absolute and relative knee extension strength than our nonobese controls. However, further studies are required to ascertain whether or not relative strength, measured with more accurate in vivo methods such as magnetic resonance imaging, is higher in obese adolescents than in nonobese controls.

Combined effects of body composition and ageing on joint torque, muscle activation and co-contraction in sedentary women

“…Increased adiposity in the young was previously shown to have a positive effect on the loaded antigravity muscles of the knee extensors in terms of both absolute MVC isometric torque (Hulens et al 2001; Maffiuletti et al 2007; Abdelmoula et al 2012) and isokinetic power (Maffiuletti et al 2007; Hulens et al 2002), but not when torque was normalised to body mass, as obese individuals were shown to be weaker (Maffiuletti et al 2007). Our current results in the plantar flexors mirror these observations.…”

“…In terms of the muscular factors of decreased strength, muscle strength is 24.2 and 22.2 % higher (absolute torque or torque normalised to thigh muscle mass, respectively) in obese compared to non-obese adolescent boys (Abdelmoula et al 2012). In contrast, lower limb maximum voluntary contraction (MVC) torque and power (both absolute and normalised to muscle volume) is lower in obese compared to non-obese persons (Hilton et al 2008).…”

Obesity-related differences in neuromuscular fatigue in adolescent girls

“…Despite this lack of consensus regarding the rate of fatigue development in obese people, we suggest that obese individuals could fatigue to a greater extent than their normal weight counterparts because of (i) their higher absolute strength/power capacity (Abdelmoula et al 2012;Maffiuletti et al 2013;Tsiros et al 2013) and (ii) their potentially higher amount of fast-fatigable muscle fibers (Kriketos et al 1997;Wade et al 1990). Indeed, it has been shown that the higher neuromuscular fatigue of healthy men vs. women was no longer observed when subjects were matched for absolute MVC force (Hunter et al 2004), suggesting that the higher the MVC force, the higher is the muscle fatigue.…”

“…Muscle contraction produces mechanical compression of the vascular supply, with the degree of compression increasing with contraction intensity (Wigmore et al 2006). Because obese girls have typically higher muscle mass and consequently greater absolute force than their normal weight counterparts (Abdelmoula et al 2012;Maffiuletti et al 2013), this could result in a greater intramuscular pressure and, hence, a higher degree of vascular occlusion during intermittent muscular contractions. This greater occlusion could limit energy supply and the removal rate of metabolic by-products and hence accelerate peripheral fatigue in the obese.…”

Abstracts of the International Congress of Research Center in Sports Sciences, Health Sciences & Human Development (2016)

“…Our findings are supported by other studies, suggesting that a specific exercise program as MAMA_MOVE should be recommended as co-adjuvant therapy for such patients. Muscle strength and body composition are two components of physical fitness and subsequent, related to health and functional performance (Abdelmoula, et al, 2012). The aim of present study was to determine the relation between lower limb strength production and some body composition variables in university students.…”