With the NAB Challenge now under way, players will shift their focus from the intensive weights and running sessions that characterise pre-season training.

On the other side of the fence, fans will get to see the results of their favourite players' dedication over summer - not only in terms of performance, but also with how they look.

The transformation in players from one season to another can sometimes, particularly with youngsters, be pronounced.

Lions.com.au takes at some of the Lions who have added some bulk over the summer months.

Harris Andrews

Andrews has added another 6kgs to his frame over the summer and is on track to improve on his breakout season in 2015.

Andrews is markedly stronger through the upper body, but just as impressive is the extra athleticism he's shown around the field during the pre-season. Last year, the 19-year-old played 19 games as a key defender with his role often having him drift across to mark as the third man up. Andrews’ extra strength will allow him to play key position as he matures.

Tom Cutler

Defender Tom Cutler continues to get stronger without losing any of his speed.

Cutler slides across the grass with ball in hand, has a thumping right boot, and at 192cm can play on either medium-size forwards or smalls.

With 18 games to his name (11 last season), Cutler has shown glimpses of his enormous talent, but he wants to lock down a spot and be a part of a defence of what he hopes will be a Lions revival.

The Heavy Lifters

Since Eric Hipwood entered ‘The Den’ in November he has made a 12.5 kg bench press improvement. Josh Schache and Rhys Mathieson have also added to their weighted max chin ups.

Tom Bell can deadlift a huge 230kg and Daniel Rich, Jaden McGrath and Lewis Taylor can now all squat more than double their body weights respectively.

And finally, after just three months into pre-season training, it looks like draftee Ben Keays has added some bulk and tone. 

Ben Keays on the night of the 2015 National AFL Draft

Keays during pre-season training in February