A 2016 paper combines data from multiple prospective cohort trials to show low sodium intake has a stronger and more universal association with increased mortality than high sodium intake. The reviewers found the only population that benefits from sodium restriction is hypertensive individuals consuming more than 6 grams of sodium per day (only 10% of the combined study population). The remaining 90% would expect to receive no health benefit or even increased health risk by reducing sodium intake. The reviewers suggest recommendations similar to those of the American Heart Association may actually be harmful for the majority of Americans.

Metabolic training refers to conditioning exercises intended to increase the storage and delivery of energy for any activity. Ultimately, the CrossFit position on metabolic conditioning, or “cardio,” is summed in two points: Anaerobic training can match endurance training for aerobic benefits. Metabolic training with varying and mixed exercise modalities avoids specificity of adaptation allowing for additional first wave-cardiovascular/respiratory adaptations and increased functional strength.