muscles retaining water

I am not too familiar with this but I googled it and some good information came up. It also says that you may notice some weight gain but that it will be temporary. Just keep track of your progress.

Here is some info from www.livestrong.com

Hydration Levels

Hard workouts often lead to a loss of electrolytes and water through heavy sweating, leading to a decrease in total body water. The amount of water stored in muscles depends on individual sweating rate, type of exercise and duration, and amount and type of fluid consumed during exercise. The availability of electrolytes will influence how much water is stored in the muscles, as muscles need sodium and other electrolytes to absorb water.
Water Weight

The amount of water stored in the muscles depends on the difference between water gain and water loss. Water gain happens through food and liquid consumption and metabolic processes. Water losses occur from respiration, gastrointestinal and sweat losses. Ideal total body water ranges from 45 to 75 percent of total body weight. The range is due the difference of water weight in body composition. Muscle tissue is about 70 to 80 percent water, while fat tissue is about 10 percent water. A hard workout will increase the metabolism, often resulting in a small increase in total body water.

Read more: http://www.livestrong.com/article/418620-do-muscles-hold-water-after-a-hard-workout/#ixzz22teD8Pel

Pretty much permanently as long as you continue to workout and progress. I find if I go on vacation for a week or something I will drop several pounds but then gain them back once I start my routine back up.