There are many sources of health and fitness tips available. Unfortunately, many offer misleading, outdated or conflicting advice. Here are some of the best resources for up-to-date, scientifically based information.

The American College of Sports Medicine (ACSM) has an excellent website that is frequently updated with current news and research findings (www.acsm.org). This organization of medical professionals sets the standards for exercise and sports medicine for all coaches, trainers and instructors in the U.S. The website allows access to portals specific to fitness in aging adults, fitness in children, and fitness for people who are dealing with specific medical conditions. The ACSM also offers an online store where books and instructional media are available for a variety of sports and exercise related topics.

According to the ACSM, healthy adults between 18 and 65 should achieve the following fitness goals:

• Moderately intense cardio 30 minutes a day, five days a week, or
• Vigorously intense cardio 20 minutes a day, 3 days a week, and
• Eight to 10 strength-training exercises, eight to 12 repetitions of each twice a week.

Moderate-intensity physical activity means working hard enough to raise your heart rate and break a sweat, yet still being able to carry on a conversation. It should be noted that to lose weight or maintain weight loss, 60 to 90 minutes of physical activity may be necessary. The 30-minute recommendation is for the average healthy adult to maintain health and reduce the risk for chronic disease.

For healthy adults over the age of 65, the ACSM recommends:

• Do moderately intense aerobic exercise 30 minutes a day, five days a week, or
• Do vigorously intense aerobic exercise 20 minutes a day, 3 days a week, and
• Do eight to 10 strength-training exercises, 10 to 15 repetitions of each exercise twice to three times per week, and

If you are at risk of falling, perform balance exercises and have a physical activity plan drawn up in collaboration with your doctor.

For general health advice, the American Heart Association (AHA) is a great source of trustworthy information. The most relevant page on their website can be found by going to www.heart.org and clicking on the “Getting Healthy” button on the menu bar. This opens up a number of further pages categorized by nutrition, exercise, stress and lifestyle issues. Everything from budgeting for healthy foods to choosing the right type of cooking oil is discussed here, along with advice on quitting smoking and making other lifestyle improvements.

If you are a woman, the AHA is now offering an online program to help women improve their cardiac health, called Go Red for Women. Check out this site at www.goredforwomen.org/ and click on the BetterUProgram on the menu bar. This free, 12-week program offers daily exercise tips and nutrition advice. By joining the program you can create a personal journal to monitor your own progress.

Finally, a new website from the U.S. Department of Agriculture explains their latest rendition of the healthy eating plan. (Go to www.choosemyplate.gov)  In addition to basic nutrition facts, this site allows for a personalized analysis of diet and exercise.

Choosing specific exercises is a very personal decision. The best exercise is one that you enjoy. Walking is almost universally a good choice, but for most people, getting a two-for-one deal makes it much more enjoyable. Enlist a friend or coworker to walk with you at lunchtime or get your spouse or kids to walk with you every evening.

For the more ambitious, start jogging with a friend or try swimming at the pond or at a local pool. Remember, it takes about three weeks of training to reinforce a new habit. Once this trial period is past, the new exercise routine will become a much more comfortable part of daily life.

Strength training also can be achieved under a variety of circumstances. Joining a gym and using weights or machines is one route. Home-based strength training can be done with virtually no equipment. Pushups, squats and lunges, and abdominal exercises can all be done with no start-up cost or travel.

Check out the Keeping Fit archives at harvardpress.com for specific exercise ideas and techniques. Just keep moving!