Manipulation of Muscle Creatine and Glycogen Changes Dual X-ray Absorptiometry Estimates of Body Composition

Abstract

21Standardising a dual x-ray absorptiometry (DXA) protocol is thought to provide a reliable 22 measurement of body composition. 23Purpose: We investigated the effects of manipulating muscle glycogen and creatine content 24 independently and additively on DXA estimates of lean mass. Results: Glycogen loading, both with and without creatine loading, resulted in substantial 34 increases in estimates of lean body mass (mean ± SD; 3.0 ± 0.7 % and 2.0 ± 0.9 %) and leg 35 lean mass (3.1 ± 1.8 %and 2.6 ± 1.0 %) respectively. A substantial decrease in leg lean mass 36 was observed following the glycogen depleting condition (-1.4 ± 1.6 %). Total body water 37 showed substantial increases following glycogen loading (2.3 ± 2.3 %), creatine loading (1.4 38 ± 1.9 %) and the combined treatment (2.3 ± 1.1 %).

No effect of increasing protein intake during military exercise with severe energy deficit on body composition and performance

“…P < .05 ** significantly different from pre depletion of carbohydrate stores at the time point of the DXA scan this may have affected FFM data. However, this should have led to underestimation of FFM level, opposing the potential overestimation caused by the timing of DXA scanning, 39 warranting further caution upon interpretation of FFM estimates. Importantly, however, DXA-derived estimates of total body mass post-exercise did not differ from floor scale based measurements ( Table 1).…”

Same-Day Vs Consecutive-Day Precision Error of Dual-Energy X-Ray Absorptiometry for Interpreting Body Composition Change in Resistance-Trained Athletes

“…LSC quantifies precision based on two consecutive scans, thus identifying the technical error inbuilt into a specific piece of equipment for a given population [7]. However, in practice, longitudinal measures are taken weeks or months apart, and despite following recommended best practice protocols [9], some level of day-to-day biological variation will be present in variables such as hydration status and muscle solute content, both of which impact results [10,11]. It is unclear what influence these factors have on body composition LSC calculations.…”

Case Study: Muscle Atrophy, Hypertrophy, and Energy Expenditure of a Premier League Soccer Player During Rehabilitation From Anterior Cruciate Ligament Injury

“…Indeed, during weeks 7-28, FFM increased in the lower limbs (1.0 and 1.0 kg in the injured and non-injured limb, respectively) and trunk (0.7 kg), collectively contributing to an increase in whole body FFM of 2.9 kg (though it is acknowledged that this may also be in due part to glycogen storage associated with increased daily CHO intakes, Bone et al, 2017). During this time, whole body fat mass also increased by 0.7 kg.…”