

Looking for training advice - Co2 tolerance and peace of mind
Hello everyone. Rookie here.
So basically I've always been obsessed by freediving and underwater fishing and I want to achieve it.
I'm a very sporty, athletic and aquatic guy (I'm a former swimmer/ open water swimming 5k, now I'm a Crossfitter but I still sail and swim). The problem is that my body completely freaks out when I'm underwater.
I've randomly tried to extend my stamina by doing random stuff but now I want to change approach.
It is impossible atm to join a Diving school as the next year I will be doing two mobilities for my master. So I am focusing on co2 static tables out of the water, as my main problem is that as soon as my co2 builds up my brain goes nuts.
As I said I'm training with co2 tables pretty much daily ever since I got my new smartwatch. It goes like this:
8 sets:
2' breathing - 15' each set
53' apnea ( I only add seconds when I'm perfectly comfortable with the previous apnea time.
What do you guys think?
I know that in the actual water everything is different, but I know that it won't be such a huge problem as co2 tolerance. I also know that I must join a school and I will asap.