Finding Your Limit

First of all, I hope you're not diving alone. What I'm about to write requires that you always have a buddy, and one that is alert and knows what he's doing with you.

At least in my case, and others I've talked to, you really don't have a way of knowing, other than trying. When you train enough, your dives will not be limited by the breathing reflex, you can simply resist it until you samba. There are signs that are individual for each person that can give some warning, but none I've found are too reliable.

When diving truly to the limit of your physiological apnea shape, you simply have to have a buddy and increase the distance slowly with each attempt. Say your pb is 75m. Next time you go to the pool, tell your buddy you're going to 78m, do it and if you're ok, on the next session you can try 80+ and so on.

Be careful of "meter hunger". Announce a maximum distance you're going to do. Don't increase you pb in huge leaps. If your pb is 75m, chances are at the 75 turn you will suddenly feel very good and start finning like crazy for hunderd. Don't...Just go a few meters after the turn and come up. Also don't try several increases in one session, save it for the next day. You cannot always trust your body. After an important turn, you may get a psychological boost for reaching that milestone and get overconfident, or when very close to your limit, you can get a kind of "endorfin storm", you feel almost euphoric and good, but in fact you're very close to bo. You simply have to know when to come up and increase your record conservatively.

Still, if you find your maximum, let's say 100m with a slight samba, don't expect that to be reliable from day to day. One day you are a bit colder, recovering from a flu, dehydraded, not rested, etc, and you will samba at 80m, so always dive with careand keep your buddy up to what you're doing.

Thanks for what you wrote Jome. It all seems to make sense. But I have a question. If you keep increasing your p.b. surely at some point you will go too far and blackout. Once someone's breathed in a load of water, will their buddy be able to save them?

there are 2 ways to improve performance:

1. increase effort with constant potential - bad
2. constant effort with increasing potential - good

by this i mean you should try not to increase your performance by pushing yourself harder (closer to your limit) each time. that will inevitably result in BO. if you always apply a constant perceived 'effort' (eg. 85-90% max, i.e. hard, but with a good margin for safety/error) then you can increase performance by increasing your potential, through training, practice, preparation, equipment etc.