Hi An,
Here are guidelines from the Centers for Disease Control and Prevention (CDC). Do make sure to do the muscle strengthening exercise since adults lose muscle as we age. You'll find the exercise recommendations are not very much different than for younger adults.
Here you go:
2 hours and 30 minutes (150 minutes) of moderate-intensity aerobic activity (i.e., brisk walking) every week and muscle-strengthening activities on 2 or more days a week that work all major muscle groups (legs, hips, back, abdomen, chest, shoulders, and arms).
OR1 hour and 15 minutes (75 minutes) of vigorous-intensity aerobic activity (i.e., jogging or running) every week and muscle-strengthening activities on 2 or more days a week that work all major muscle groups (legs, hips, back, abdomen, chest, shoulders, and arms).
ORAn equivalent mix of moderate- and vigorous-intensity aerobic activity and muscle-strengthening activities on 2 or more days a week that work all major muscle groups (legs, hips, back, abdomen, chest, shoulders, and arms).
If you want even more health benefits
5 hours (300 minutes) each week of moderate-intensity aerobic activity and muscle-strengthening activities on 2 or more days a week that work all major muscle groups (legs, hips, back, abdomen, chest, shoulders, and arms).
OR2 hours and 30 minutes (150 minutes) each week of vigrous-intensity aerobic activity and muscle-strengthening activities on 2 or more days a week that work all major muscle groups (legs, hips, back, abdomen, chest, shoulders, and arms).
An equivalent mix of moderate- and vigorous-intensity aerobic activity and muscle-strengthening activities on 2 or more days a week that work all major muscle groups (legs, hips, back, abdomen, chest, shoulders, and arms).
And here are excellent resources.
http://www.webmd.com/healthy-aging/nutrition-world-2/exercise-older-adultshttp://www.acsm.org/docs/current-comments/exerciseandtheolderadult.pdfhttp://journals.lww.com/acsm-msse/Fulltext/2009/07000/Exercise_and_Physical_Activity_for_Older_Adults.20.aspx
http://www.nia.nih.gov/health/publication/exercise-physical-activity-your-everyday-guide-national-institute-aging-1http://nihseniorhealth.gov/exerciseforolderadults/healthbenefits/01.htmlhttp://www.cdc.gov/physicalactivity/everyone/guidelines/olderadults.htmlYou can post your diet-related questions to the Diet Community:
http://exchanges.webmd.com/diet-exchangeKeep us posted on how you're doing.
Take care, Rich
Rich