The current physical activity guidelines undervalue vigorous activity. Vigorous activity may be 4–9× more potent than moderate activity for reducing all-cause mortality, cardiovascular disease, diabetes, and cancer risk. The exercise guidelines assume a 2:1 ratio between moderate- and vigorous-intensity activity: two minutes of moderate activity equals one minute of vigorous. That’s why the recommendations are 150–300 minutes of moderate or 75–150 minutes of vigorous activity each week. But new