Answer;
-Hypotonic
Explanation;
A hypotonic solution is any solution that has a lower osmotic pressure than another solution. It is a solution that has less solute and more water than another solution.
In a hypotonic solution, there is more free water outside the cell than inside the cell. As a result, water will diffuse into the cell through the process of osmosis
If an individual is sweating a lot, he/she are losing two things: water and salt . This means that their blood is losing both as well. The loss of salt is important because you need a certain salt and water concentration for proper cellular function. At the moment one sweating, with the cells losing water, they are moving towards a hypertonic phase. One would want a hypotonic solution to replace lost salts.