Isotonic
Isotonic refers to a solution that has the same concentration of solutes as another solution, typically a cell's internal environment. This balance allows for the equal movement of water in and out of the cell, maintaining its shape and function. Isotonic solutions are important in biological processes, such as in the use of IV fluids in medical treatments.
In exercise science, isotonic can also describe a type of muscle contraction where the muscle changes length while maintaining a constant tension. This is commonly seen in activities like lifting weights, where the muscle shortens during the lifting phase and lengthens while lowering the weight.