I see a lot of Crossfit bashing on here so I will put in my two cents. The main site alternates its WODs 3 on 1 off in a pattern as follows. Day 1: Gymnastics Day 2: Gymnastics/MetCon Day 3: Gym/MetCon/Strength Day 4: Off Day 5: MetCon Day 6: MetCon/Strength Day 7: MetCon/Strength/GYmnastics Day 8: Off Day 9: Strength Day 10: Strength/Gymnastics Day 11: Strength/Gymnastics/MEtcon Day 12: Off

Definitions: Gymnastics... Push Up, Pull Up, Air Squat, Sit Up. Muscle Up etc... Strength... Power lifts and Olympic Lifts MetCon (Cardio).... Running, Rowing, Double-Unders,

I am a CF trainer between gyms right now. Every gym is different and some gym owners don't know thier ass from a hole in the wall. Some program long chipper-style workouts because it gets the clients to feel like they are doing something. I have programmed days of just a strenth WOD and people are like "That's all?" The average housewife wants to sweat and move for the 45min to an hour. Thats why HIIT is so popular. Working on GOATs like Hand Stand Push Ups people don't want to do. CF is a great Strength and COnditioning program is it the best for a sport specific athlete .....No! Hence CF Football, and CF Endurance. The best for the "average" person, I truly belived if programmed correctly yes. But only is programmed correctly and with people that are willing to get out of thier comfort zone and do things they aren't good at sometimes. I am a firm believer in Crossfit but I am not the typical Crossfitter that thinks its the "Best and Only Way" It has flaws and I am not afraid to admit that, but its still new. They will work themselves out. As for Crossfit forcing out Paleo. That is not true. They preach PaleoZone. Robb Wolf as the Head of the no longer given Nutrition Certification said at a seminar that Zone is stupid and Dave Castro blew up on him so Robb said "Go EFF yourself" and Dave the Douchebag fired him. Worst thing CFHQ has ever done. I saw video of the day it happened. They still preach Paleo but its Zoned.

To completely answer your question: I do think we are designed for that much intensity. An early human might very much had to chase and kill with little to no tools or weapons, drag, lift, and clean all in a very short time to keep other predators from stealing thier kill. This was done daily sometimes with failure.

The human body is capable of doing some amazing things and can be conditioned to adapt to almost anything. Just think about the crazy workout regiment of an athlete like Michael Phelps who has to consume 10k calories a day just maintain optimal levels during training.

That being said, yes you could do CrossFit 6 days a week and do long/short metabolic conditioning and you would probably walk around very strong and fit and on the surface it would seem that you are healthy.

What I find more interesting is, "Does CrossFit or metabolic conditioning type workouts have a positive effect on longevity?" I would have to say, "No!"

That type of intense strain on your joints and body, in the long run, is probably going to decrease your life expectancy and not be a positive factor in living a long, and healthy life. I think if you would rather live a shorter, fitter life than go ahead beat yourself up in the gym

Just think about the grueling workouts and games that American pro football players go through; it's a proven statistic that their average life expectancy is around 55 years of age. Yes, Terrell Owens is an amazing specimen of athleticism and overall strength but is he going to out live somebody who is fairly active, lives a stress-free life and eats clean; probably not.

Then again, sitting in front of the computer, slamming Dr. Peppers, eating pizza and playing World of Warcraft all day is probably not great for you either.

Bottom line: life is about balance; don't beat yourself up, listen to your body, and try and live a low-stress life.

There is a line. And it depends on the CF gym. They are EXTREMELY not all the same. Some are wonderful places and some are dumps. There is no control over an affiliate. This is my major concern with CF, and it also allowed its(unchecked) growth. So you might get PT level help ant one and douchebag level help at another. In my personal and professional experience most people need alot more strength before they do metcons or they burn you up.

So, to answer your question, Never go by the main site. Ever. Crossfit has created a culture of good people who might train you. So find a good one.

No, it's very well designed for inducing injuries, though I could suggest some additions--punching a brick wall as hard as you can (10 times in a row), Jumping out of tree, climbing back up it and jumping out again (5 times), jumping rope with a heavy chain (for 20 mins), etc.

I don't do crossfit, but I do weights 3x a week and a lot of slow cardio and after 2-3 days of that I need to just lounge around, eat a little extra and just be a sloth. I don't think its healthy to push our bodies so much- rest is important too. Paleo man wasn't running around killing buffalos or sabertooths or whatever every single day. He chilled too.

I do CF 3 days on 1 day off, eat a strict Paleo diet, get enough sleep, and feel AMAZING 99% of the time. I have so much energy from my diet that I love working out and feel great after the high intensity stuff. So yes, I believe our bodies were designed to be fit, healthy and strong - which in my opinion is the epitome of Crossfit.

Its up to the person - If you enjoy it and feel like it, do it, if not, dont!

I have been Crossfitting in addition to running,dancing professionally, etc for years. I personally believe (based on my own methodology) that Crossfit should be SOMETHING you do, not the ONLY thing you do. We were born to run, walk, climb, lift heavy stuff, play, swim, etc. By including a plethora of activities into your daily life, you will get the best results.

I am a competition ballroom dancer, Crossfitter, I do yoga, and run. I feel I am well rounded and that is what works for me. Some people can focus too much on aesthetics, performance, or get tricked into thinking that more is always better. Listen to your body.It will tell you when it needs you to up the intensity, slow down, stretch, relax, etc.

Crossfit provides some excellent core stabilization and high intensity work, which our Paleolithic ancestors would have found to be fundamental in their daily lives. But getting your "Fran" time to under 2 minutes or being able to row 5K in 1:20, etc. can be more personal milestones. I think every person is different and if it makes you feel great and you are not constantly inflamed or getting injured, then do it! Anything is better than sitting on the couch mindlessly eating bon bons all day.

Why do crossfit, when you can get benefits without injury?

I think the subquestion "are we designed to work out that way" is meaningless, because we are (almost all) aspiring to look and perform in ways we are not designed to look and perform...

that being said, I personally feel that there are better ways to achieve the physique and performance (if that is not crossfit performance) of your dreams than "crossfitting"