I am at day 23 and have been experiencing almost the same as described above. The tiredness/weakness happened in the first 1-2 weeks, then improved, got Tigrr blood! The past three days I am exhausted and my legs feel weak. I also workout at 5am and do intense cardio for 90+ minutes 6 days a week. I have been eating a few bites of grilled chicken pre-workout. My breakfast is later, once I am at work and is a large egg muffin with bacon, spinach and tomatoes, small piece of baked potatoe and a clementine. The one thing I have changed recently is to remove some high FODMAP foods as my stomach had been very uncomfortable all day- like "that hunger pang but I just ate and want a tums" feeling. I also started steaming all veggies vs. eating them raw. I eat mostly protein and veggies, some fruit, and cut way back on the nuts the past few days. I really don't want to extend my 30 days or start over but I don't want to start the re-introduction if I am still feeling bad as I don't think it would give reliable info. Any suggestions on the weakness/stomach upset? I should also say I take Zantac for reflux and my reflux was under control pre-whole30. Now it seems worse. The reduction of high FODMAPs the last 3 days has reduced the stomach pit pangs described above, but also seems to have timed exactly with the exhaustion/ weakness. Any advice would be greatly appreciated! Thx in advance! I forgot to mention, I normally sweat a ton during my intense cardio workouts. The past 2 weeks I am not sweating even close to my normal. I have been salting all my food so I don't think that is why.