Young midfielder Jesse Lonergan will enter the season significantly lighter after shedding 5kg during the off-season.

Lonergan, 21, came to the SUNS just over three years ago as a powerhouse midfielder that made his living by bulldozing through contests.

But with the rotation cap to drop from 120 to 90, the SUNS decided he needed to drop weight from his 91kg frame to help improve his fitness and allow him to get around the ground better. It's meant a change of diet for the Tasmanian, with the SUNS essentially periodising his carbohydrate intake around heavy training sessions.

READ: Lonergan's year of learning paying strong dividends

The results speak for themselves as Lonergan has lost body fat but maintained lean muscle mass and kept his strength and power – elements that are so important to his game.

If Sunday's opening NAB Challenge match is any indication, it's worked - Lonergan collected 23 disposals (16 contested) and had 10 clearances to be his team's best and cement himself as a best 22 player.