How to summarise column in bottom row

We have a Google Sheets sheet where we track workouts. The first column is the exercise name, followed by a column for each workout day:

A               B       
Bob         01/01/2024
_CORE      
crunches    BW / 5 3 80s

_METABOLIC
running     M / 6 6m
walking
--------------------------
SUMMARY    01/01/2024
           _CORE
           crunches BW / 5 3 80s
           _METABOLIC
           running M / 6 6m

We’re trying to make a summary of all exercises done in the bottom row. In our current attempt we succeeded but we’re struggling to get the summary in one cell, without the blank rows.

Here is a test sheet with an example.

Thank you for your help.

>Solution :

Here’s a generalized approach which you may adapt accordingly:

=reduce(C1,A3:A20,lambda(a,c,textjoin(char(10),1,a,if(left(c)="-",regexreplace(c,"^- ",),let(Σ,index(C:C,row(c)),if(Σ="",,"- "&c&" "&Σ))))))