What are your biggest physical struggles?

i am overall very weak and don't have a lot of endurance. Plus my achy body, but I just keep trying to work at it. The worst thing I could do is give up.
I will not give up I will keep going, keep working on improving myself.

I have restrictive airway disease and RA that has also started attacking my lungs as well as joints (nodules that grow on my lungs and then shrink), and I also have ... ummm... some physical pain issues that details are not necessary on. Overcoming them comes from your drive, determination, and perseverance. If you want something bad enough you can taste it, then you do what you have to do in order to accomplish it. First step was getting my doctor on board with how I felt about fitness and wanting to get farther along in the game. Next step was building myself up. When pain is too bad, I won't ignore and do more damage, but I also won't allow it to be an immobile obstacle either. If I am not able to do weights one day due to the pressure it puts on an area, then I go jogging. If I am not able to get enough air for jogging due to lungs that day, then I go fast walking and insure heart rate still climbs. There is always a "work-around" for obstacles... I have been able to still improve stamina, still improve strength, and still reshape myself - though it may take a bit longer than it would for someone in peak health... but I am ok with that, as progress is progress