I think the comment about slim athletes sustaining injuries was apt, but more because, if it's possible to injure yourself exercising when you are NOT carrying excess weight, it's that much easier, and the injury will be more severe, if you are.
My husband is an athlete. He's also a 4.0 tennis player (USTA bumped him up from his comfort zone of 3.5, last year), and runs a sub 1:30 half marathon. This year he went up an age group, to the 55-59, and his just under 1:28 got him 4th place in his "big" half at Grandma's Marathon in Duluth.
But. He's had severe knee pain, to the point of needing crutches, from landing all his weight on one leg, going up after a lob. Not even an injury; he has arthritis in both knees, and the lack of cushion made the force of the landing dangerous.
His brand new tennis shoes, with torsion that was too stiff, betrayed him on a turn, and he sprained an ankle, which, two years later, needs to be supported for tennis.
He tore his gastrocnemius doing hills, three weeks before Grandma's, a few years ago.
His weight varies between about 165 during training and 175 in the winter, when he does more lifting.
Any of those injuries, with significant extra weight, could have caused a lot more damage.
Me? I walk a lot. After a head injury, I'm a little leery of any activity that could bump my head.
But, just maybe, in a couple years, I'll go back to downhill skiing. I miss it more than golf, biking, and kayaking all together.