Fitness and goalkeeper coach Anthony White spoke to Latics Player after going through testing with the players at the University of Bolton yesterday.
The 23-year-old, who is the youngest coach in the Football League, devised a series of tests with head physio Craig Schofield as the players retuned to pre-season training.
He said: "We had the lads since early in the morning and they did every test that me and Craig have decided to do. They started in the morning with basic tests with Craig and then they have moved on to counter-movement jumps and then they finally finished off with the VO2 Max which is the dreaded test for everyone.
"The counter-movement jumps measures the power in the legs and the VO2 Max is the maximum output they can produce on a treadmill. Obviously we can take that into training and tailor training based on the results we have got."
The young coach mixes his fitness coach role with training the club's goalkeepers. One player who he has coached from a young age is current number one, Joel Coleman.
"Joel has done fantastic. I have known him since the age of 11 when I was in the youth team and everyday he just works hard," he admitted.
"I've worked with him for a couple of years now, since the age of 16 and he's a fantastic lad and I hope for the best for him this season."
Watch the full interview on Latics PlayerHD.