which of these plans is better?

i work out with a friend on tuesdays. i pretty much let him decide what we’re doing as he is in excellent shape and also has the willingness to kick my very lazy ass.

on thursdays and sundays, i usually do some kind of sprint workout, usually five 300yd. hill sprints, at about 65-75%, followed by five 75yd. flat sprints at 80-90%.

i’m 47 years old and about 20 lbs. overweight. my goal is fitness. i was a sprinter when i was younger and still love it.

on fridays, i do another workout, usually with weights. my question is, should it be a mix of upper and lower body, or just upper body and add another sprint workout on the same day? my schedule doesn’t really allow me to switch up the days.