Experience has taught me how important breath holding is and the benefits it can bring about.
I work as a freediving instructor and train a lot of beginners. While some of them will never become freedivers, I have seen how much of a benefit they have had from life-sustaining exercises.
I have also trained surfers, paddlers and open water swimmers who have gained confidence and courage through my courses. Once they understand the physiology of breath-holding and learn their own limits, they can focus more on the performance aspect of their own specific sport.
Breath control training has also brought a lot into my own life, both for diving and leisure.
I have set 3 world records in freediving. As of this writing, I hold the world record for ice diving 103 meters from hole-to-hole in only a swimsuit.
One of the biggest reasons I was able to successfully attain this performance in cold water, is due to my ability to cope with different sensations through the help of breathing exercises.
Exposure to cold is based upon the same thing as breath holding. Therefore, training to hold your breath will also help you get used to the cold.