Monday, January 28, 2013

Is 30 Minutes Exercise Better Than An Hour A Day?

Having regular exercise forms part of a healthy lifestyle. According to American Heart Association’s (AHA) Guidelines for Physical Activity, people should have at least 150 minutes per week of moderate exercise or 75 minutes per week of vigorous exercise (or a combination of moderate and vigorous activity) to improve their heart health.

As overweight is a risk factor for heart disease, people who are overweight often tend to think that if they exercise for a longer duration, they should be able to lose more weight. Is this true? A study that was published in 2012 in the ‘American Journal of Physiology’ could probably answer this. 

Researchers from University of Copenhagen followed 60 heavy and healthy men for 13 weeks and reported that people who had a daily exercise of 30 minutes lost weight as much as those who had a 60-minute exercise.

In the study, half of the participants were assigned to exercise for one hour a day, wearing a heart-rate monitor and calorie counter. The remaining half was asked to exercise 30 minutes a day. It was found that people who exercised for 30 minutes a day was enough to lose weight.

The findings showed that participants who exercised 30 minutes a day lost 3.6 kilos in 3 months. In comparison, those who exercised for an hour a day only lost 2.7 kilos. The reduction in body mass, however, was about 4 kilos for both groups.

Sound unbelievable?

One possible explanation provided by the researchers is that participants found half an hour of exercise achievable for them and they had the desire and energy for more physical activity after their daily exercise session. It is also possible that the participants who exercised for 60 minutes a day ate more so they lost weight slightly less than anticipated.

The findings, however, have some limitations. The study involved only young men, whose metabolisms and weight-loss motivations might differ significantly from those of other age groups and women. Meanwhile, the study duration was rather short. It is likely that the results might change if the period of continued exercise is longer.

Monday, January 21, 2013

Does Stress Cause Weight Gain Or Vice Versa?

The primary causes of obesity, as highlighted by the World Health Organization (WHO), are diet high in fat, salt and sugar, and lack of physical activity. Of course, there are other factors that could also make people become overweight or obese. For instance, stress can make a person fat, too.
In the present fast pace environment, people are constantly under tremendous stress, which could come from their boss, co-workers, peers or even family members. Stress can contribute to weight gain in a number of ways. One of them is do with cortisol, a stress hormone. When human bodies are under stress, the fight or flight response is triggered leading to release of various hormones.
With an intention to explore how stress and obesity might be linked and find out the cause and consequence relationship between stress response and obesity, researchers from University of Stavanger, Norway reviewed a number of previous studies showing weight gain and cortisol levels were noticeably higher in people who became fatter because of stress.
They finally established a hypothesis: “stress and obesity could reinforce each other through positive feedback”. In other words, stress can make one fat and being obese can create stress as well. Their findings were published on March 28, 2011 in ‘Medical Hypotheses’.
According to their arguments, getting fatter could potentially trigger the stress response that would encourage additional weight gain. When a person gains weight, the body also filled with stress, which would probably make this person gain additional weight.
Meanwhile, they also suggested out that dieting could also stimulate cortisol production that might trigger the stress response and thereby prevent the weight loss. If their hypothesis were correct, people will have to break the stress cycle if they want to prevent weight gain.
Perhaps, the new hypothesis could help people understand and cope with obesity, which can likely cause them to develop chronic diseases including diabetes, heart disease and stroke.

Monday, January 14, 2013

Why Should You Be Physically Active?

Health experts have long regarded and recommended exercise and physical activities to help people keep fit. Over the past 60 years or so, the health benefits of a physically active lifestyle have been the core of many studies and research. As early as in 1953, an article published in the medical journal ‘The Lancet’ revealed the link between physical activity and coronary heart disease. Of course, physical inactive could put people at higher risk of getting many other diseases, including cancer, high blood pressure, high cholesterol, and Type-2 diabetes.
Recently, health experts reported on July 18, 2012 in ‘The Lancet’ that a third of the world’s adults are physical inactive and such lifestyle kills about 5 million people each year.
A person is said to be physical inactive, as defined in the study, when this person fails to do 30 minutes of moderate physical activity 5 times a week, 20 minutes of vigorous activity 3 times a week, or a combination of the 2. According to researchers’ findings, inactivity increases with age and is higher in women than in men, and is more commonly found in high-income countries.
Their findings also showed that about 3 out of 10 individuals aged 15 years or older (about 1.5 billion people) do not have the experts’ recommended amount of physical activity, and approximately 4 out of every 5 individuals aged between 13 and 15 years old are not moving enough.
In another study also published in ‘The Lancet’ on the same date, researchers argued that physical inactivity was a risk factor comparable to smoking or obesity. After comparing physical activity levels with population statistics on diseases such as diabetes, cancer and heart disease, they reported that physical inactive claimed more than 5.3 million people out of the 57 million deaths worldwide in 2008.
The study revealed that about 6 percent of coronary heart disease cases, 7 percent of Type-2 diabetes cases and 10 percent of breast and colon cancers cases were caused by a lack of exercise.
Based on a rather conservative estimation made by the researchers, a reduction of physical inactivity by 10 percent could reduce more than 500,000 deaths each year.
It is sad to say that people nowadays spend more time in cars and in front of computers instead of walking, running and cycling more. People really require exercise to help their bones, heart, muscles and other organs function optimally.
Perhaps, people should not spend too much time on sedentary activities. They could start exercising and slowly build up the frequency and duration in order to match the recommended guidelines.

Monday, January 07, 2013

Can Omega-3 Fatty Acid Reduce Heart Disease And Stroke?

Omega-3 fatty acid, which can be found in fish oils, squid oil and some plant oils like flaxseed oil, are considered essential fatty acids. While they cannot be synthesized by the human body, they are vital for normal metabolism.
For years, health professionals believe that omega-3 fatty acid can help prevent heart disease and other ailments, as supported by a number of clinical trials. While the underlying mechanism is not clear, it is possible that studies that showed some heart health benefits from consuming omega-3 fatty acids might be due to their ability of lowering triglyceride levels, prevent serious arrhythmias, or even lower platelet aggregation and lower blood pressure.
However, its health benefits remain controversial as there is a lack of conclusive evidence to link it with a lower risk of all-cause mortality.
A study appeared in September 12, 2012’s issue of the ‘Journal of the American Medical Association’ (Jama) reported that omega-3 fatty acids had no effect in lowering the risk of stroke, heart attack or death.
Researchers from the University Hospital of Ioannina in Greece examined 20 studies involving 68,680 randomized patients who were given supplements of omega-3 polyunsaturated fatty acids. It was found that there were 7,044 deaths, 3,993 cardiac deaths, 1,150 sudden deaths, 1,837 heart attacks, and 1,490 strokes. Analysis of these figures did not show any statistically significant association with reduction in death, stroke or heart disease.
Prevailing guidelines suggest using omega-3 fatty acid as supplements or through diet for patients after heart attack. In the United States, the Food and Drug Administration (FDA) has approved its use as triglyceride-lowering agents in patients with overt hypertriglyceridemia. In Europe, there are certain national regulatory approving use of omega-3 supplements to lower the risk of heart disease and stroke.
Based on the findings, the researchers do not suggest using omega-3 proactively in trying to optimize heart health. In their opinion, it is necessary to conduct further research, including, in their own words, ‘an individual patient data meta-analysis to refine possible associations related to, among others, dose, adherence, baseline intake, and cardiovascular disease risk group’.