Legs Hurting Bad

Ok to start off… I’m in good shape and I’ve been training pretty hard the last 2 months. Yesterday I did a session of HIIT and today I was trying to do 3-4 sprints of 80 yds but could barely do 2.

My quads (and only my quads) were hurting so bad to the point where I didn’t want to injure myself. I don’t know exactly why my legs hurt, and I don’t know what’s causing it? Side note: doesn’t feel like lactic acid, or that pump feeling.
And I had a banana afterwards, hoping the K+, potassium, would help alleviate the pain. Any responses would be helpful. thx

HIIT can get you very sore. The pain is your body’s way of telling you to back off. If you are going to do HIIT on back to back days, vary the method of training. For instance, one day you can do interval sprints, one day you can hit the heavy bag, one day you can do the stepmill or incline treadmill, etc. Personally I’d only do 2-3 HIIT sessions per week, as they are very draining. Great for fat loss but not so great for strength gains.