Leg free fatty acid kinetics during exercise in men and women

The Exercise responses section reports increased circulating palmitate release during exercise, and the Discussion describes the study as 90 minutes of moderate-intensity exercise at about 45% of peak oxygen consumption (page not provided). The paper does not establish that fatty acid oxidation is the primary energy source across 25–65% of V̇O2peak, or identify VLDL-TG-derived fatty acids and intramuscular triglycerides as fuel sources. (LLM, conf=0.86)

The Exercise responses section reports similar arterial plasma palmitate concentrations in men and women during exercise (P = NS), supporting the similar-concentrations part of the claim. The Discussion notes differences among prior studies but does not establish that some found higher plasma FFA concentrations in women. The protocol describes a controlled prestudy diet, not a fed-state exercise test; no page numbers are available in our copy. (LLM, conf=0.82)

The Exercise responses section reports no sex difference in palmitate rate of appearance during exercise, supporting the comparable-rates finding. But the Assays and measurements and Calculations and statistics sections identify the isotope tracer and calculated rate as palmitate, not glycerol; this paper does not establish comparable glycerol Ra. (LLM, conf=0.84)

The Abstract and Exercise responses section report isotope-tracer measurements showing no significant sex difference in systemic or leg FFA release during exercise. The claim’s “fed state” qualifier is not established: the Methods describe a controlled diet before the study but do not say participants exercised in a fed state. The verbatim citing sentence, which omits that qualifier, is supported. (LLM, conf=0.85)

The Discussion (page not available) reports similar systemic and leg free-fatty-acid release in men and women of comparable fitness during exercise. It also distinguishes this study’s direct measurements from plasma glycerol concentrations used as an indirect measure in previous studies. The cited paper therefore supports a lack of sex difference in fatty-acid release, but not the specific claim about plasma glycerol concentrations. (LLM, conf=0.84)

The Discussion says direct comparisons with previous studies are difficult, but attributes that difficulty to differences in measurement methods, exercise protocols, fitness, and diet—not to body-weight versus fat-free-mass definitions of flux. The Exercise responses section reports systemic palmitate flux in µmol/min; it does not establish the claimed normalization distinction. (LLM, conf=0.82)

The Discussion reports similar systemic and leg FFA release in men and women during exercise. It does not report an FFA:glycerol ratio; it mentions glycerol only as an indirect measure used in previous studies. The Methods describe a controlled diet before the study but do not establish that exercise occurred in a fed state. (LLM, conf=0.84)

The Abstract and Discussion report that systemic and leg FFA release increased similarly in men and women during moderate-intensity exercise. The Subjects and Subject characteristics sections describe nonobese participants of comparable fitness, but do not establish that they were recreationally active. (LLM, conf=0.83)

The Abstract reports exercise at 45% of peak oxygen consumption, and Exercise responses reports no significant sex difference in systemic respiratory quotient during exercise. The paper does not establish the claimed result at 25%, 65%, or 85% VO2peak, and its direct FFA measurements concern uptake and release rather than oxidation. Page numbers are unavailable in our copy. (LLM, conf=0.86)