Resistance training: An effective way to lose weight?

Resistance training helps build up muscle mass. As muscles consume more energy than fat, those who are muscular burn off more calories, even at rest. But does this mean resistance training is an effective way to lose weight?

Actually, the energy expended during resistance training is not as great as the energy expended during prolonged (at least 30 minutes) of low to moderate intensity aerobic exercises, says Png Eng Keat, a physiotherapist at Singapore General Hospital's Department of Physiotherapy.

"Resistance training alone is never recommended for weight loss and neither should it be the cornerstone of a weight loss program," he adds. Between aerobic exercises and resistance training, aerobics are more effective for burning off fat.

But still, muscular people burn off more calories, right?

The idea that increasing muscle mass is enough to burn more calories is a myth, says Png. While it is true that increasing muscle mass boosts the resting metabolic rate, the energy expended at rest per kg of muscle mass is low - between 17 to 33 kcal per day, which is only about 175 kcal on average per week.

Related video: How to exercise right and reap all the benefits - video

Besides, resistance training usually has a steeper learning curve than aerobic training for beginners, which means it may take longer to attain the proper intensity of training. Once that is achieved, muscle gain may start at a growth rate of about 200 to 400 g of muscle mass per week.

In short, for a beginner who wants to lose fat, increasing muscle mass in order to burn more calories alone would not produce results, explains Png.

How much should you exercise?

The American College of Sports Medicine (ACSM) recommends a healthy caloric deficit of 500 to 1,000 kcal per day in order to lose weight. To lose 0.5 to 1 kg per week -- a safe limit for weight loss — you need a deficit of 3,500 to 7,000 kcal per week.

According to the ACSM, prolonged low to moderate intensity aerobic exercises such as brisk walking, jogging or cycling are good for weight loss. It recommends about 200 to 300 minutes per week of such physical activity for long-term weight loss.

Although resistance training shouldn't be the focus of a weight-loss exercise plan, some elements should be incorporated to maintain or increase muscle mass in individuals, recommends Png.

Related article: Can home exercises be as good as exercising in the gym?

Fat-burning zone

Usually, during prolonged low to moderate intensity exercise, your body utilises a combination of fats and carbohydrates. The so-called "fat-burning zone" is the intensity at which your body utilises the greatest proportion of fat as an energy source.

This intensity is at 60% of your maximum oxygen consumption (VO2max), explains Png. An easier way of finding your "fat-burning zone" would be to use a "heart rate reserve formula".

First, you need to calculate your estimated maximum heart rate (MHR). If you are male, subtract your age from 220; if you are female, subtract your age from 226. When your exercising heart beat is between 60 and 70 per cent of your MHR, you are in the "fat-burning zone".

E.g. a 40-year-old man's MHR would be 180 (220-40), and his fat burning zone would be between 108 and 126 heart beats per minute (60 to 70 per cent of 180).

However, Png says: "A well rounded weight loss plan should include a restriction in caloric intake as well. It is no use exercising if you don't restrict your caloric intake."

Have questions on "How to Exercise to Lose Weight"? Health Xchange offers you the chance to get physiotherapists' answers for FREE in its "Ask the Specialist" online Q&A session this month (August 2012). BONUS: The first 20 people to post a valid question will receive a free thumb-drive! Visit HealthXchange.com.sg, Singapore's trusted health and lifestyle portal.

Staying fit and fab

Here are some tips to get you going on a regular exercise regime.

• Start small: If you are unable to commit 150 minutes a week to exercise then commit 50 minutes. It is better to start small than to not start at all, and gradually increase the frequency.

• Find somewhere convenient: If you are very busy then exercise at a location near your work place or your home. Even getting off five bus stops earlier and brisk walking to your home is a good way to exercise.

• Include family and friends: Exercising with others is more fun and they can be your source of encouragement when you are feeling lazy or discouraged.

• Do something you like: Choose an activity that you enjoy so that you are more likely to keep doing it over the long term.

Interested in knowing your metabolic rate? SGH LIFE Centre is looking for research study participants. You will know your exact resting metabolic rate, daily energy needs and body composition, which will help you tailor your daily energy intake to aid in weight management. Best of all, it's FREE!

This article was written by Gloria Chan for Health Xchange, with expert input from the Department of Physiotherapy, Singapore General Hospital (SGH).

Find more health-related tips and articles on HealthXchange.com.sg, Singapore's trusted health and lifestyle portal.

Health Xchange's articles are meant for informational purposes only and cannot replace professional surgical, medical or health advice, examination, diagnosis, or treatment.