For strength with minimal weight gain some favorites are
Anavar,
test prop, halotestin,
tren
These are good for sprinting and
furazabol may be a good one too.
Winny is probably good if the athlete doesn't get joing pain from it.
Avoid
deca, dbol and too much
test.
At a total dose of 600mg/week you should see nice strength gains and not gain too much weight if your diet/cardio is okay. If your sport has an endurance element be careful that you don't let your bp get too high and allow some time to get used to performing at a new strength level. Sometimes this can affect endurance.