To find the total number of sit-ups Ishaan did in 29 days, you can multiply the number of sit-ups he did each day by the number of days:
\[ \text{Total sit-ups} = \text{Sit-ups per day} \times \text{Number of days} = 148 \times 29 \]
Now, let's calculate that:
\[ 148 \times 29 = 4292 \]
So, Ishaan did a total of 4292 sit-ups in those 29 days.