Definition of "isotonic" [i•so•ton•ic]

• Of equal tension. (adjective)
• Isosmotic. (adjective)
• Having the same concentration of solutes as the blood: an isotonic saline solution. (adjective)
• Physiology Of or involving muscular contraction in which the muscle remains under relatively constant tension while its length changes. (adjective)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "The magazine also included articles on fashion, food and gadgets such as the "Tensolator," which provided "bodybuilding isotonic tension," perhaps to make up for slow nights in the rumpus room."
• "The company touts the beverage as an isotonic, vitamin-rich, no-additive beverage with natural regenerative powers that help athletes recover from a workout."
• "Erdinger market their beer, amusingly, as an isotonic, low-calorie, vitamin enriched sports drink."