When I say you lose strength I dont mean you're not progressing through the gvt. Let's say you bench 315 max. When you start your gvt you bench you'll probably have to drop bench to like 160 ish to be able to get through the 10x10. And you'll be able to progress nicely through that. But were I noticed my strength went down was when I went back to trying to lift heavy after stopping my gvt (specifically through a cut). After going through gvt for let's say 4 weeks. You maybe be able to bench 180 for 10x10, but try and get that 315 for one. That's were I believe the strength loss comes from. From not working the that 80 to 90% 1rm range. I think gvt is great, for growing in a bulk. To change up a stagnant routine. But not so great during a deficit.