Hey Loveday,
overtraining will actually worsen Your performance and make life unnecessarily hard.
So now You have an excuse to take it easy for a day or so.
What about the tables do You not understand? I'd be happy to explain.
You've been snorkeling/freediving for seven years now? Cool! I used to be a vacation-snorkeler for some years before I started freediving, but have only started freediving last Year.
What did You do in those years? Any training at all? How often did You go diving? Who taught You to equalize and such? Dad/mum/SO/buddies/friends?
