People looking for support and community – This is the appeal to CrossFit for me: every CrossFit gym has a really tight-knit community feel to it. You’re not just a membership payment to them; you’re a person that needs support. When Nerd Fitness gyms start popping up (don’t think it won’t happen!), I’ll be drawing a lot of inspiration from CF as to how members are so supportive and inclusive of each other.
The digestive abilities of anatomically modern humans, however, are different from those of Paleolithic humans, which undermines the diet's core premise. During the 2.6 million year-long Paleolithic era, the highly variable climate and worldwide spread of human populations meant that humans were, by necessity, nutritionally adaptable. Supporters of the diet mistakenly presuppose that human digestion has remained essentially unchanged over time.
Paleo diets are based on a simple premise – if the cavemen didn’t eat it, you shouldn’t either. So long to refined sugar, dairy, legumes and grains (this is pre-agricultural revolution), and hello to meat, fish, poultry, fruits and veggies. The idea is that by eliminating modern-era foods like highly-processed carbs and dairy, you can avoid or control “diseases of civilization” like Type 2 diabetes and heart disease, and likely lose weight too. What you eat and how much depend on your goals or the specific program you’re on, if you choose to follow one. The high-protein diet is ranked poorly among U.S. News experts, who consider it too restrictive to be healthy or sustainable.
I often get caught up in focusing on numbers and scales, so I decided not to officially weigh myself before or after Whole30. But I can attest that everything about my body just felt better. I know saying something like "I lost eleven pounds" would sound much more convincing, but I could see that my stomach was slimmer, as was my face (which is awkwardly the first place I gain weight).
A 2015 study in the Journal of the American College of Cardiology found that 76 people who followed the Paleo diet for 60 days (as well as those who followed vegan, Mediterranean and DASH plans for the same length of time) lost an average of 9 pounds and showed improvement in their blood pressure levels. The effects were greatest and most sustained among people who also attended regular diet support group meetings.
Fresh fruits, fresh vegetables, fresh meat—the paleo diet is all about eating foods straight from the Earth just as our ancestors did. Those ancestors didn't have livestock or crops to call their own, so Cordain advises to go with grass-fed and organic varieties whenever possible to limit exposure to pesticides, antibiotics, and other chemicals that didn't exist back then. Research from Emory University suggests that Paleolithic people obtained about 35% of their calories from fats, 35% from carbohydrates, and 30% from protein.
"CrossFit is not a specialized fitness program, but a deliberate attempt to optimize physical competence in each of 10 recognized fitness domains," says founder Greg Glassman in the Foundations document. Those domains are cardiovascular and respiratory endurance, stamina, strength, flexibility, power, speed, coordination, agility, balance, and accuracy.