Here’s a subtle way to work your anaerobic threshold with some underwater swimming.
We preface this set with an important WARNING: Any type of prolonged breath holding or hypoxic training is dangerous and should be attemped only if you are in good physical condition and only with proper supervision. It should be introduced gradually into a training program, and it should be discontinued if you experience ANY signs of dizziness, disorientation, headache/pressure, or other unusual physical symptoms.
The goal of this set is NOT to see if you can do an entire length under water. The goal is not to see if you can do HALF a length under water. The idea is to spend SMALL AMOUNTS of time under water and to try to get to the point where you can RELAX and actually SLOW DOWN while you’re under the surface.
This is a fairly moderate set. If you get to the point where you can manage this, then you could either extend the distance of each interval, or increase the number of intervals that you do in the set.
5 X 100 breaststroke on a sendoff that gives you approximately 25 seconds rest
Each 100 is swum as:
25 underwater drill: Alternate three breaststroke kicks under water with arms in streamline and 2 full strokes of breaststroke on the surface
25 underwater drill as described above
While you are kicking under water, focus on trying to RELAX your body and your breathing. Keep everything streamlined. At the start of each breaststroke length, make sure you do a full pullout!
For additional ideas of underwater breaststroke drills, pick up a copy of GO SWIM BREASTSTROKE DRILLS WITH STACIAN STITTS AND DAVE DENNISTON.