Smoking, obesity, hyper-tension and cholesterol have been the enemies of good health for a long time, but in recent years added to this list is a new obstacle to overcome: lack of physical activity. The 1996 Surgeon General's Report, the document that regularly 'declares war' on main risk factors for the population that cause health problems, gave it as fact.

Countless studies have shown (and continue to do so) that regular physical activity has exactly the same beneficial effect as taking drugs to combat fundamental problems such as high blood pressure and cholesterol. And that's not all: regular aerobic activity and weight training are important both for beginners and the elderly.

In order to stimulate the cardiovascular system properly exercise should involve large muscle groups, in a repetitive programme and last for at least 20 minutes. Furthermore, intensity should be moderate in order to avoid both a reduction in performance and muscle fatigue.

The benefits of cardiovascular activity are numerous, kicking off with an improvement of cardiac function, especially the contractile capacity and vascularization of the heart. Then there is the functional improvement of the entire respiratory apparatus due to the increase of air breathed per minute (pulmonary aeration), caused by an increase of the frequency and depth of breaths taken. It should be emphasized that shallow, fast breaths allow the air in the 'dead space' (or the air in the windpipe and bronchus) to be changed, but only supply small quantities of oxygen to the lungs. Someone who works out, on the other hand, manages to supply a greater quantity of oxygen to the pulmonary cavity with less fatigue to breathing muscles.

As far as blood is concerned, cardiovascular training means improved consistence which in turn helps the pumping action of the heart. Other positive changes are linked to a reduction of 'bad' LDL cholesterol and triglyceride, and, as a result, an increase in 'good' HDL cholesterol, plus a reduction of the risk of ischemia. There are also hormonal benefits, with an increase of thyroxin (a rise of basic metabolism) and insulin (against glycemia).

Muscles are less vascularized, both superficially and in texture, due to an increase in the capillary network (the opening of new ducts not previously used): this can favour an up to 40% increase of blood/muscle exchange together with a reduction in peripheral resistance, meaning a lowering of blood pressure.

Furthermore, one of the most notable benefits caused by aerobic activity is obviously a reduction in weight, if exercise is carried out regularly and for medium-long sessions.

In conclusion, physical exercise is also a positive influence on stress and keeps anxiety, insecurity and fear at bay, as well as having a good effect on mood, lowering tension and reducing depression.

But who should be exercising? And are there any special limits? Cardiovascular training is for people who already exercise regularly, both amateurs and professionals, with benefits also obtainable for those with a sedentary lifestyle, the elderly, the overweight (naturally) and different groups of people including diabetics and those suffering from high blood pressure. Your doctor's advice is obviously indispensable.

 As a general guideline, cardiovascular training should be carried out 3-5 times a week for between 20-60 minutes of either continuous or intermittent aerobic activity (a minimum of 10 minutes per time accumulated throughout the day), at between 55-65% and 90% of maximum heart-rate (the index of training intensity and the 'rev-counter' of a human machine), between 40-85% of maximum VO2 (or aerobic capacity, that is a person's 'engine displacement').

So - let's start working-out!