killahbee, I got a good workout for you to try useing the harness,sled and farmers all at once.
do a farmers walk while harness dragging your sled at the same time, I did this last night with 155lb an arm farmers while dragging 175lb sled on grass for 100'sets, man it hits evrything this can duplicate a truck pull and build awsome hip strength, you got the equipment right?, give it a shot sometime.