Changes in single skinfold thickness in 100 km ultramarathoners

Abstract

BackgroundChanges in single skinfold thickness and body fat have been investigated in ultraswimmers and ultracyclists, but not in ultrarunners. The present study investigated the changes in single skinfold thickness during a 100 km ultramarathon.MethodsFirstly, we investigated associations between prerace preparation and prerace body composition and, secondly, changes in single skinfold thickness during a 100 km ultramarathon in 219 male ultramarathoners. Changes in fat mass and skeletal muscle were estimated using anthropometric methods.ResultsKilometers run weekly prerace and running speed during training were negatively associated with all skinfold thicknesses (P < 0.05) except for the front thigh skinfold. During the race, skinfold thickness at the pectoral (−0.1%), suprailiac (−1.8%), and calf (−0.8%) sites decreased (P < 0.05). The subjects lost 1.9 ± 1.4 kg of body mass (P < 0.001), 0.7 ± 1.0 kg of estimated skeletal muscle mass (P < 0.001), and 0.2 ± 1.3 kg of estimated fat mass (P < 0.05). The decrease in body mass was positively related to the decrease in both estimated skeletal muscle mass (r = 0.21, P = 0.0017) and estimated fat mass (r = 0.41, P < 0.0001).ConclusionFirstly, prerace fat mass and prerace skinfold thickness were associated with both volume and speed in running training. Secondly, during the ultramarathon, skinfold thickness decreased at the pectoral, suprailiac, and calf sites, but not at the thigh site. Percent decreases in skinfold thickness for ultrarunners was lower than the percent decreases in skinfold thickness reported for ultraswimmers and ultracyclists.

Muscle damage, physiological changes, and energy balance in ultra-endurance mountain-event athletes

“…However, the observed difference between the skinfold thickness before and after the race in this study was only observed in the triceps site. These results are consistent with those of Knechtle et al (2012) who found small decreases in individual skinfolds (from 0.0 to -2.8%) but an increase of 4.8% in the triceps skinfold. In addition, the significant decrease in the calf girth, higher than in the rest of girths could be associated with a large strain of running in this part of the lower limb (Knechtle et al 2012).…”

“…The loss in body mass following the event is consistent with data obtained in 100 km ultramarathoners (Knechtle et al 2012), ultra-endurance cyclists (Bischof et al 2013) and ultraendurance open water swimmers (Knechtle et al 2012). Bischof et al (2013) showed a larger decrease in individual skinfold thicknesses (from -6.4 to -14.9%) and in the sum of skinfolds (-10.7%) in cyclists.…”

Anthropometric profile, body composition and somatotyping of national Iranian cross-country runners

“…A further anthropometric characteristic related to endurance performance is the circumference of limbs of the upper arm, the thigh and the calf (15,17,29). …”

Can the Performance Gap between Women and Men be Reduced in Ultra-Cycling?

“…However, in ultra-endurance sports, some of the above-mentioned anthropometric and physiological characteristics can be of advantage, for example, a higher percentage of body fat serving as an energy store [29]. Furthermore, ultra-endurance sports are less dependent on anaerobic energy supply, which is preserved by the impact of testosterone.…”