It might not be the right forum to ask this question, but I know that many cyclists visit gym, which has been discussed on the podcast many times. Once a week I do six sets of squats with a bar on my shoulders (80 Kilos + bar weight). After a few weeks I have permanent blisters on the back of my shoulders. Is there any way to fix this? I think the T-shirt that I am wearing in the gym might be an issue, it is not a gym T-shirt. Or maybe I need to put a towel on my back? What can you suggest?
Blisters form when the skin gets chafed / rubbed. Examine why the barbell is moving when you squat. Focus on locking it into place.
If you need extra padding then a towel or different shirt would work. Some gyms have a plastic / hard rubber adapter that clips onto the bar and better contact points with your shoulders and back.
Manta Ray Squat Pad (there are other brands)
Some t-shirt have stitches where the bar makes contact. In that case, try another model where he stitches are positioned differently.
I’ve tried synthetic materials and cotton t-shirts. I think I prefer cotton. The bar slides less and the material is thicker so it’s more comfortable. The downside is that it gets wetter.
Try a slightly narrower grip if you can. That will lock the bar in place better. Push you elbows back.
ProFitness Barbell Pad Squat Pad- Shoulder Support for Squats, Lunges & Hip Thrusts - for Olympic or Standard Bars https://www.amazon.com/dp/B073G8VN4N/ref=cm_sw_r_cp_api_glt_i_WDDJ2W3X2PK3H1HAVBPQ?_encoding=UTF8&psc=1