Legging alterations with sewing machine

[Mcmcmcmc]

I have a pair of Sweaty Betty power leggings that I’ve only worn a couple of times but are half a size too big around the legs (knees and ankles in particular). Is it too daft to try to tighten them with a sewing machine? The fabric is 62% polyamide and 38% elastane.

See you've had no reply. It would be fine. Use a narrow zigzag or lightning stitch so that it can stretch without snapping the thread.
www.lovesewingmag.co.uk/learn-to-sew/item/how-to-sew-jersey-on-your-regular-sewing-machine/

Thank you @PickAChew I will give this a try