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Abstract Background Astronauts in Earth's orbit experience microgravity, resulting in a decline of skeletal muscle mass and function. On Earth, models simulating microgravity have shown that the extent of the loss in muscle force is greater than the loss in muscle mass. The reasons behind this disproportionate loss of muscle force are still poorly understood. In the present study, we hypothesize that alongside the loss in skeletal muscle mass, modifications in the expression profile of genes encoding critical determinants of resting membrane potential, excitation‐contraction coupling and Ca2+ handling contribute to the decline in skeletal muscle force. Methods Healthy male volunteers (n = 18) participated in a 5‐day dry immersion (DI) study, an Earth‐based model of simulated microgravity. Muscle force measurement and MRI analysis of the cross‐sectional area of thigh muscles were performed before and after DI. Biopsies of the vastus lateralis skeletal muscle performed before and after DI were used for the determination Ca2+ properties of isolated muscle fibres, molecular and biochemical analyses. Results The extent of the decline in force, measured as maximal voluntary contraction of knee extensors (−11.1%, P

Abstract Background Cancer patients at advanced stages experience a severe depletion of skeletal muscle compartment together with a decrease in muscle function, known as cancer cachexia. Cachexia contributes to reducing quality of life, treatment efficiency, and lifespan of cancer patients. However, the systemic nature of the syndrome is poorly documented. Here, we hypothesize that glucocorticoids would be important systemic mediators of cancer cachexia. Methods To explore the role of glucocorticoids during cancer cachexia, biomolecular analyses were performed on several tissues (adrenal glands, blood, hypothalamus, liver, and skeletal muscle) collected from ApcMin/+ male mice, a mouse model of intestine and colon cancer, aged of 13 and 23 weeks, and compared with wild type age‐matched C57BL/6J littermates. Results Twenty‐three‐week‐old Apc mice recapitulated important features of cancer cachexia including body weight loss (−16%, P