I've been experimenting with doing long bouts of underwater swimming to get ready for my upcoming trip to Cancun :) This is a trick I found while reading The Oxygen Advantage that seems to work allowing me to stretch my underwaters to about 60meters and hold my breath about 2:30-3:00 mins comfortable, kinda
Try it and take note of its effects on your exercise performance.
You can take baking soda about an hour before
½ teaspoon baking soda
2 tablespoons apple cider vinegar
1. Put the baking soda in a glass.
2. Add the apple cider vinegar and stir for about 1 minute, or
until the soda is thoroughly dissolved.
3. Down the hatch.