Thyroid hormone receptor α in skeletal muscle is essential for T3‐mediated increase in energy expenditure

International audienceHIGHLIGHTS • Thyroid hormone receptor alpha 1 (TRa1) is critical for fiber type composition in slow twitch muscle. • TRa1 loss-of-function in skeletal muscle does not affect exercise capacity or voluntary running. • In the absence of muscle TRa1, increased sarcolipin expression might safeguard basal metabolic rate and exercise capacity. • Thyroid hormone-induced increase in metabolic rate (thyroid thermogenesis) is dependent on TRa1 in skeletal muscle. • Thyroid hormone-induced elevation in body temperature is independent of skeletal muscle TRa1