Strength training: How to prevent age-related muscle loss

If you listen to what the media tells us, you probably believe that in order to transform an obese body into a body of normal weight in a short period of time, you have to push yourself to physical extremes.

In Wednesdays e-alert, I told you about the revised US Department of Agriculture (USDA) dietary guidelines that recommend 60 minutes of exercise every day to prevent weight gain, and 90 minutes per day for weight loss.

Simply put, thats excessive. As weve seen in several studies, just a few minutes of exercise each week can eventually make a big difference to your overall health. But theres one simple factor that many people leave out of their exercise regimens that provides important benefits: strength training. 

Benefits x 4 

According to a report from the US Centres for Disease Control and Prevention (CDC), only a very small percentage of older adults are doing enough to keep their muscles strong.

In an interview with Reuters Health, Dr. Judy Kruger, a CDC specialist in care for the elderly and chronic disease prevention, noted that exercises designed to strengthen muscles (such as weight training or resistance training) yield several benefits, including:

 Reducing the risk of falls and fractures
 Increasing endurance
 Promoting healthy bone density
 Improving insulin sensitivity

But even though strength exercises promote general good health and make it easier for older people to carry out normal daily activities, a 2001 survey revealed that only 12 percent of people aged 65 to 74 perform this type of exercise on a regular basis.

A little goes a long way

Another key benefit provided by strength training is an improvement of exercise capacity. Its a simple concept: If you have a high exercise capacity, then generally speaking youre in good health. But people who rate the lowest exercise capacities have a much higher risk of chronic diseases.

In a previous e-alert, I told you about research from the University of Florida (UF) in the US that measured exercise capacity and aerobic power in subjects 60 to 85 years of age who participated in resistance training exercise.

More than 60 volunteers were randomly assigned to either a low-intensity exercise group or a high-intensity exercise group. All the subjects performed resistance exercises three times each week for six months. At the end of the study, the UF team found that both levels of exercise significantly improved the participants exercise capacities. But the researchers were surprised by this result: The subjects in the low-intensity group showed GREATER gains in exercise capacity and oxygen peak than the high-intensity group.

In other words, you dont have to push yourself to intense levels of exercise to get the best results.

One more benefit

Obviously, weight training increases muscle strength, but older people get yet another benefit: prevention of sarcopenia - the age-related loss of skeletal muscle.

A report from the International Longevity Centre-USA, details a variety of studies of subjects aged 60 to 96 who overcame the loss of strength and body mass associated with sarcopenia by using weight training regimens that lasted from 8 to 12 weeks. In as little as two sessions a week, most subjects increased their strength, while also improving balance and mobility. Subjects who continued their weight training regimens also increased metabolic rate and the ability to climb stairs.

Exercise specialists with the US National Institute on Ageing (NIA) advise older people to start with light weights - only one or two pounds - and then gradually increase the weight according to whatever feels comfortable. And Dr. Kruger also points out that a few simple exercises that are easy to do at home are all thats required to improve muscle strength. So dont let anyone tell you that you have to pump iron like a body builder to reap these healthy benefits.

. . and another thing

An HSI member named Allie would like some help figuring out the measurements she finds on supplement bottles and in the e-alerts. Allie writes:

What is an IU; an MG, an MCG? Are there mgs in a mcg; mcgs in an mg? What is the relationship to IUs? I find it impossible to compare one supplement with another because I dont know what these abbreviations stand for. Articles talk about one should take so many milligrams a day of something (vitamin C, for instance) for good health, but one bottle has vitamin C - so many mcgs; another has vitamin C - so many mgs. Please help!

Most of Allies question is easy to answer, although things get a bit sticky with the IUs. Heres a quick rundown:

 One thousand micrograms (mcg) equal a milligram (mg)
 One thousand milligrams equal a gram (g)
 One thousand grams equal a kilogram (kg)

IUs are international units, and they dont fit neatly into the metric system of mass that uses the kilogram as the base unit. For each substance thats measured in IUs, theres an international agreement that specifies the expected biological effect that will occur with a dose of 1 IU. For instance, 1 IU of vitamin C is equal to 50mcg (although youll almost always see vitamin C dosage in either milligrams or grams). One IU of vitamin E (which Ive never seen in any measurement other than IUs) is equal to 2/3 mg.

And thats about the size of it.