Exercise to lose weight: time or intensity?

More and more people are turning to exercise to lose weight and stay healthy, but the same question often comes up: to lose fat, should we do moderate exercise for a longer period of time or vigorous exercise for a short period of time?

First, you should know that we are talking about aerobic exercise - the type of effort increases metabolism, which, in turn, increases calorie expenditure. These are the best exercises you can do to lose weight, and can be done at moderate or high intensity. Intensity is considered moderate if you are a bit hot and are breathing quicker than at rest. Intensity is high if you are hot and breathing quickly without actually becoming out of breath. Think cross-country skiing on flat ground, snowshoeing in shallow snow, speed-walking or light winter jogging, swimming, or using a cardiovascular exercise machine (stationery bike, elliptical machine, treadmill, step machine, etc.).
 
Focus on Duration
 
This is a realistic approach. If you want to lose weight, and you are not in shape, you will find it easier to do moderate exercise versus high-intensity exercise. Plus, you will be less likely to injure yourself, which is a risk when an unfit person starts straight into vigorous exercise. By putting the emphasis on duration, you give yourself the chance to exercise every day and control your weight. If you exercised intensely, you would have to sometimes take days to rest to allow your muscles to recuperate.

This being said, how long should you practise moderate aerobic exercise? The best thing to do during the first few weeks is to schedule in three ten-minute sessions of exercise (or two 15-minute sessions) during the day, if possible every day. The idea is to stimulate your metabolism two or three times a day, for a total of 30 minutes of moderate physical activity, which is the minimum amount of exercise recommended by experts for people to remain healthy. This plan will help you use up about 150 calories more per day, or 1,000 more per week. If you want to speed up weight loss and are very motivated, you can gradually increase your total exercise sessions to 45 minutes a day. You will lose, more or less, one pound of fat in less than 2.5 weeks as long as you do not increase the calories you eat.

Secondly: Intensity

After one month of moderate exercise, you will have improved your physical condition and started to lose weight. You can then think about increasing your training. There are two advantages to higher intensity exercises: better cardio and more calorie expenditure per minute. By doing more vigorous exercises, you also create a larger “energy debt” for your body. In other words, after doing so, your metabolism remains high and you continue to burn calories for two or three extra hours without lifting a finger! This post-exercise burn, often “forgotten” when calculating the number of calories used, is immense, especially if you exercise several times a week.

Compromising with Intervals

The major problem with intense exercise is that you could lose motivation in the long run. Therefore, it is worthwhile to integrate more intense work into moderate exercise sessions: in other words, interval training. Let’s say you speed walk at about 110-120 steps per minute. During your 10-to-15- minute session, walk even quicker for about 30 seconds every two minutes at a pace of about 130-135 steps per minute. You can apply the same principle to swimming, cross-country skiing, winter jogging or running on a treadmill. Why are intervals beneficial? They increase the number of calories burnt without increasing the time you exercise. In concrete terms, you will still be exercising for 30 minutes a day, but you will be burning 1,300 calories a week instead of 1,000.

In fact, interval training provides great results for those who want to lose weight and improve their health through exercise. A study at the Centre of Preventive Medicine and Physical Fitness at the Montreal Heart Institute confirmed the effectiveness of this type of exercise. Nine months after following the Kilo-Actif program, 62 obese people participating in the study lost an average of 5.5% of their body mass and 5.15% around their waist. Moreover, they had increased their physical ability by 15%. Their bad cholesterol (LDL) had dropped by 7%, and their good cholesterol (HDL) had climbed by 8%. And all that in under a year!

Move Every Day to maintain weight

Recently researchers at the Mayo Clinic in the USA revealed the essential role that daily physical activity plays in regulating our weight. Twenty subjects (10 slim and 10 obese) were equipped with a sophisticated system for evaluating daily calorie expenditure and then monitored for ten days. They noticed that the slim subjects burned approximately 350 calories more per day than their obese counterparts. Also interesting: the obese subjects were sedentary for two hours longer per day.

The Most Effective Type of Exercise?

When it comes to getting off the sofa and moving around, anything is better than nothing. But experts have found that not all exercise is created equal.

When it comes to heart health, cardiovascular - or aerobic - exercise is what you need to focus on, with stretching and weight training playing a supporting role.

Good forms of cardiovascular exercise include swimming, which is an overall body workout and which really gets your heart pumping; walking, when done with purpose; and running, which  is well known for its overall health benefits and has a great impact on heart health in particular.

If you prefer to exercise at a gym there are a great number of aerobic classes to choose from, including spinning, aerobics, Tae-bo and many more. You can also join a dance group and learn salsa or ballroom dancing, both of which are extremely good cardiovascular exercises and just so happen to be great fun.

The American Heart Association advises that whichever option you choose, to be effective you must do it regularly, three to four times a week, for a minimum of 30 minutes and it must increase your heart rate for the duration. You can also break your exercise sessions down to 10 minutes three times a day, if necessary.

And while weightlifting may make you look good on the outside, the experts advise that unless it is done in conjunction with aerobic exercise it will not have much of an impact on heart health.

Don't forget; The heart is a muscle, so the stronger it is, the more effective it will be in pumping blood around the body, improving oxygen transport and circulation. 

And the more physical activity we do the better chance we have of lowering our blood pressure, and the less pressure there is on the heart the healthier it will be.

An active prescription

Good news, hot on the heels of our prize-giving events, where Dr. Steven Blair expressed concerns over physicians neglecting to recommend exercise: More and more U.S. adults are being told by their doctor to get out and get active, according to government survey released this week.

Nearly 33 per cent of adults who saw a doctor in the previous year said they were told to exercise. That was up from about 23 percent in 2000, the Centers for Disease Control and Prevention reported.

The report also found more women got that advice than men. And among people with chronic health problems, diabetics, were the most likely to get the advice and cancer patients were least likely.

The most dramatic - and surprising - increases were reported in patients age 85 and older. In 2000, about 15 percent were told by doctors to exercise. By 2010, almost 30 percent were getting such a recommendation. "It's very encouraging that doctors feel people at that age still have time to live and can make their health better," said Pat Barnes, a CDC health statistician who was lead author of the report.

The report was based on a survey of nearly 22,000 adults in 2010. The CDC then compared the results to similar surveys done in 2000 and 2005.

The doctors' advice may be getting through to at least some people. Other CDC data has found that about 51 percent of Americans said they exercise regularly in 2009, up from about 46 percent in 2001.

However, more than one third of U.S. adults are obese, a statistic that's held steady for nearly a decade.