20 km in a week after a break .

Hi everyone.

I'm planning on doing 20km spread in 5 sessions. That would mean 4km per session. 4 k takes me about 1 hour and 20 minutes.

I normally do up to 10-12 km in 4 sessions a week. I haven't swam since last Saturday and this will I would only be able to do 1 session of 4 k.

Is it too much to jump into 20km in one week after having a week "break" ?