It's going to be a couple of months till we can ride the boys, they're turned out daily and exercise each other playing 'tig' round the fields...

... but one of the boys is susceptible to weight gain.
He doesn't mind being lunged, will 15 minutes a day be beneficial to him or am I wasting my time? I know a human has to do more than that to have any benefit, but this boy is a bit overweight to start with so I don't want to push him.
What would you suggest please?
thanks
Zayna x