We need to seize any opportunity to reduce the amount of time we spend sitting, we need to learn how to bring activity back into our lifestyle.
Physical activity will have these beneficial health effects regardless of your body weight and regardless of the weight loss result if any that you achieve from being active.
A recent US study looked at the effects of a 30-minute walk on a wide range of immune function measures.
They analysed blood samples from healthy volunteers after sitting quietly for 30 minutes and after walking briskly for 30 minutes.
They found that a 30 minute walk led to positive changes in several immune system components. Whereas sitting for 30 minutes was not associated with any such beneficial changes.
This study adds to the existing bulk of evidence to show that moderate activity (activity that raises the heart rate to between 60-65% of its maximum rate) leads to positive immune changes, by increasing the number of immune-system cells in the blood.
The authors suggest that these immune changes may explain why regular moderate exercise is associated with fewer upper respiratory tract infections and consequently, fewer days off due to sickness.
Ref: Nieman et al (2005). Medicine & Science in Sports and Exercise, Vol 37, No 1. p57-62
Research shows that physical activity can increase energy levels.
Large scale surveys asked people to report on how active they are, and how often they feel tired.
The more active a person is, the more likely they are to report frequent feelings of energy. Sedentary people experience more feelings of low energy and fatigue.
Experiments have been conducted that either increase or decrease the amount of activity a person does to see how this affects their feelings of energy.
When a group of healthy young men were forced to endure 20 days of bed rest, they reported much higher levels of fatigue and much lower levels of energy than before the experiment.
Patients with various fatigue-related medical conditions, who were given between 10-20 weeks of exercise training reported large increases in feelings of energy and vitality, compared to similar patients who didn't receive any exercise.
The review came to the following conclusions:
More Activity = Less Fatigue - There is a clear link between doing regular physical activity and feeling more energetic and less tired.
Less is More - The best type of activity to increase feelings of energy is low to moderate intensity activity. More intense athlete style training can actually have the opposite effect on feelings of energy by creating a form of activity burn-out.
Who gains the most - The people who will experience the biggest increases in energy levels from taking regular exercise, are those who are currently sedentary and who already report feeling fatigued.
In other words, the people with the greatest need, will get the most benefit.
Ref: O'Connor & Puetz. (2005) Medicine & Science in Sports and Exercise. 37: pp299-305.
The short answer to this question is yes. Most importantly, exercise can help keep weight off in the long term. Exercise can help you manage your weight in two ways:
Much of the weight re-gain that people experience after dieting is due to the metabolism slowing down and the loss of muscle that occurs. In general terms – if you lose muscle, your metabolism will slow down. This is why 'quick fix' weight-loss diets are ineffective in the long-term. People who diet without exercising will almost always put all the weight back on; some may even gain extra weight.
Exercise increases your lean muscle mass. Muscle weighs more than fat so it is possible that your weight could actually increase in the short-term following exercise. In which case, do not be disheartened – you need to stop thinking in terms of body weight and start thinking in terms of fitness body composition* which are much more important.
*Body composition is the amount of lean muscle tissue in the body in comparison to the amount of fat.