Which statement best describes GLUT4 translocation in skeletal muscle with training?

Which statement best describes GLUT4 translocation in skeletal muscle with training?

• A. GLUT4 translocation is inhibited by training.
• B. Increases GLUT4 translocation to the membrane during and after exercise.
• C. GLUT4 is expressed only in adipose tissue.
• D. GLUT4 does not affect glucose uptake.

Answer: (B)

Training enhances the movement of GLUT4 transporters to the muscle cell surface, especially during and after exercise. GLUT4 sits in intracellular vesicles and is moved to the sarcolemma in response to contraction or insulin, allowing glucose to enter the muscle. With regular training, not only is there more GLUT4 available in the muscle, but the signaling that drives its translocation becomes more efficient, so during exercise there’s greater GLUT4 at the membrane and glucose uptake is increased; after exercise, this enhanced capacity for glucose disposal can persist. This explains why training boosts GLUT4 translocation to the membrane during and after exercise, improving glucose uptake. The other statements don’t fit because training does not inhibit GLUT4 translocation, GLUT4 is present in skeletal muscle (not only adipose tissue), and GLUT4 activity directly affects glucose uptake.

Training enhances the movement of GLUT4 transporters to the muscle cell surface, especially during and after exercise. GLUT4 sits in intracellular vesicles and is moved to the sarcolemma in response to contraction or insulin, allowing glucose to enter the muscle. With regular training, not only is there more GLUT4 available in the muscle, but the signaling that drives its translocation becomes more efficient, so during exercise there’s greater GLUT4 at the membrane and glucose uptake is increased; after exercise, this enhanced capacity for glucose disposal can persist. This explains why training boosts GLUT4 translocation to the membrane during and after exercise, improving glucose uptake. The other statements don’t fit because training does not inhibit GLUT4 translocation, GLUT4 is present in skeletal muscle (not only adipose tissue), and GLUT4 activity directly affects glucose uptake.