2008 Physical Activity Guidelines 2008 U.S. Physical Activity Guidelines Aerobic exercise 2.5 hours per week of moderate intensity OR 1.25 hours vigorous intensity Segments should last for at least 10 minutes Additional health benefits 5 hours (300 minutes) per week of moderate intensity OR 2.5 hours per week of vigorous intensity Strength training At least 2 days per week 8-12 repetitions of exercises for major muscle groups