3-4#/week is a lot
Backpacking 20-25 miles per day or cycling touring 80-100 miles per day for 4-5 weeks will do it or should say has done it for me.
Subcutaneous fat loss is most effective at about 25% of VO2 max. Touring pace all day does that. (If you don't stuff yer face)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5766985/