Читать книгу The GI Walking Diet: Lose 10lbs and Look 10 Years Younger in 6 Weeks - Joanna Hall - Страница 16

Your resting metabolic rate (RMR) is the amount of calories your body requires just to live. It’s determined by your weight and the amount of muscle and body fat you have. As we age, RMR tends to decline. This is partly due to decreased muscle mass. It’s also affected by changes to your nervous system, specifically the sympathetic nervous system (SNS), slowing the response time between brain messages and muscle movement. Resting metabolic rate is what most people mean when they say ‘basal metabolic rate’ (BMR). These two terms are used interchangeably, although they are not technically the same.

As part of the normal ageing process, most body organs decrease in functional capacity, resulting in a 2 per cent decline in BMR each decade. However, if physical activity also declines, BMR will decrease more quickly, and there will be a greater increase in fat mass. This means that, over time, your metabolic rate slows down, and weight gain will occur unless you decrease the amount of calories you consume and increase your level of physical activity. Your metabolic rate may also decrease as the cardiovascular, gastrointestinal and respiratory systems slow down with age, which can influence digestion, absorption and nutrition needs.

What This Means to You

The biggest impact of a reduced RMR is that you will find it more difficult to maintain a healthy weight, and you may experience weight gain.

What You Can Do

Experts are divided on how much weight gain is a product of the natural ageing process and how much is attributable to other factors, such as decreased energy expenditure through physical activity. But one thing’s certain: decreased physical activity results in less muscle mass, which in turn impacts upon your RMR or the rate at which the body burns calories. But it doesn’t have to be like this …

Action Worth Investing In

By following the six-week plan, specifically the walking and strength programme, you can feel confident that you will lose weight.