The paleo diet runs on the same foods our hunter-gather ancestors supposedly ate: fruits, vegetables, meats, seafood, and nuts. "By following these nutritional guidelines, we put our diet more in line with the evolutionary pressures that shaped our current genetics, which in turn positively influences health and well being," says Loren Cordain, PhD, professor of health and exercise science at Colorado State University and author of The Paleo Diet. He says the diet lessens the body's glycemic load, has a healthy ratio of saturated-to-unsaturated fatty acids, increases vitamin and nutrient consumption, and contains an optimal balance of protein, fat, and carbohydrates.
Grass-fed meat is recommended on the paleo diet because it is leaner than meat from grain-fed animals and has more omega-3 fatty acids, the healthy fats that reduce inflammation in the body and protect your heart. A typical American diet is high in saturated and trans fats and lower in healthy poly- and monounsaturated fats, hence the paleo diet's emphasis on grass-fed meats.
CrossFit is a strength and conditioning program consisting mainly of a mix of aerobic exercise, calisthenics (body weight exercises), and Olympic weightlifting. CrossFit, Inc. describes its strength and conditioning program as "constantly varied functional movements executed at high intensity across broad time and modal domains," with the stated goal of improving fitness, which it defines as "work capacity across broad time and modal domains." Hour-long classes at affiliated gyms, or "boxes", typically include a warm-up, a skill development segment, the high-intensity "workout of the day" (or WOD), and a period of individual or group stretching. Some gyms also often have a strength-focused movement prior to the WOD. Performance on each WOD is often scored and/or ranked to encourage competition and to track individual progress. Some affiliates offer additional classes, such as Olympic weightlifting, which are not centered around a WOD.
CrossFit gyms use equipment from multiple disciplines, including barbells, dumbbells, gymnastics rings, pull-up bars, jump ropes, kettlebells, medicine balls, plyo boxes, resistance bands, rowing machines, and various mats. CrossFit is focused on "constantly varied, high-intensity, functional movement," drawing on categories and exercises such as calisthenics, Olympic-style weightlifting, powerlifting, Strongman-type events, plyometrics, body weight exercises, indoor rowing, aerobic exercise, running, and swimming.
This is not hard. Don’t you dare tell us this is hard. Fighting cancer is hard. Birthing a baby is hard. Losing a parent is hard. Drinking your coffee black. Is. Not. Hard. You’ve done harder things than this, and you have no excuse not to complete the program as written. It’s only thirty days, and it’s for the most important health cause on earth—the only physical body you will ever have in this lifetime.
This 2003 CrossFit Journal article captures an early conception of a universal, multi-event test of fitness that laid the foundation for CrossFit competition, including what would become the CrossFit Open and the CrossFit Games. The design requirements for such a test "included but were not limited to the following: quantifiable results; consistency with the CrossFit fitness concept; raising our commitment to improving absolute strength, relative strength, and gymnastic foundations; balancing intrinsic abilities of smaller and larger athletes; emphasizing exercises critical to and foundational to advanced training; mixing training demands within each test and, of course, over the total competition; a design that would identify an athlete’s weaknesses and possibly stand as a workout plan for improving overall fitness; and, finally, we wanted to design a competition that would be 'hard as hell.'"