The use of hot tubs to help relax sore muscles is a well known benefit. Warm water therapy can ease painful joints, reduce inflammation and take the weight off your joints minimizing discomfort and stress.
Hot tubs, in general, can increase your overall wellness but increasing circulation, which improves healing, decreases stress and anxiety caused by injury and can help facilitate a better range of motion.
You can even improve your workout by soaking in hot water which will allow you to stretch better which prevents injury and sore muscles and allow you to sleep better at night.