I just started doing X-fit a few month ago. So far, I love it. However, I'm not improving very fast. In fact, at times I still feel like I'm going to puke or pass out. I get nauseated and spots in my eyes.
After taking some meticulous notes, I've noticed that the culprit seems to be intense compound lifts. To clarify, I have NO trouble with Deadlifts, Squats, Rows, Push Press, etc. What DOES give me fits are Burpees, WallBalls, Thrusters, Walking overhead lunges, etc.
While the deadlifts et al are technically "compound", they are different from what makes me sick in two ways. First, they don't really require the same level of full body intensity - compare a squat with a thruster for instance. Second, The things on the first list are typically done for maximal effort, or maybe 10 to 15 reps at most. Where as with something like Burpees or Overhead Walking lunges, you might be doing 10 to 30 reps as fast as possible.
Also important to mention, I have no issue with "endurance" per se. i've done a Marathon and 3 1/2 marathons - one as recently as 6 weeks ago.
So I can run for 4 hours fine. Lift heavy just fine. Lift compound movement just fine. But 5 to 10 burpees and I'm losing my balance and getting tunnel vision.
I remember that there is a term (or technique) that involves rapidly switching the part of your body doing work. It forces your body to re-distribute blood quickly from say your legs to your arms. Could this be what I'm bad at?
Any knowledge or theories any of you have will be very appreciated. I hate being bad something and I'd love to have a diagnosis and plan to improve.