A cold is an inflammation of the upper respiratory tract caused by a viral infection. The common cold is probably the most frequently occurring illness in humans worldwide. More than 200 different viruses cause colds, and rhinoviruses and coronaviruses are the culprits 25-60 percent of the time. Rhinovirus infections often occur during the fall and spring seasons, while the coronavirus is more common during the winter.
The U.S. Centers for Disease Control and prevention estimates that over 425 million colds and bouts of flu occur annually in the united States, resulting in $2.5 billion in lost school and work days, and in medical costs. The average person has two or three respiratory infections per year. Young children suffer from six to seven annually.
How do you catch a cold?
Although still a matter of controversy, growing evidence suggests that at
least among adults, cold viruses are passed from person to person primarily
by being inhaled into the nose and air passageways (i.e. spread
through the air). Severe colds transmit viruses more readily than mild ones
because a greater amount of virus is passed into the air by coughing and
sneezing. Thus, to hinder the spread of cold viruses, coughs, sneezes
and “nose-blows” should be smothered with clean handkerchiefs or facial tissues. Contrary to popular opinion, damp, cold or drafty weather does not increase the risk of getting a cold. According to most cold researchers, cold or bad weather simply brings people together indoors, which leads to more person-to-person contact.
Doctors often quip that a cold lasts seven days without treatment, and one week with it! Most non-prescription medications, such as antihistamines, decongestants, cough medicines, and analgesics provide only temporary relief of symptoms. These medications can make you feel more comfortable while your body’s immune system gears up to fight off the infection. To get rid of the cold, your immune system must make enough antibodies to destroy the viruses, a process that takes three to four days.
Antibiotics that fight bacteria have no value in the treatment of the uncomplicated common cold which is caused by a virus. Even the old standby – inhaling steam — has little or no beneficial effect on cold symptoms! Vitamin C does not prevent colds, according to most researchers, but may slightly reduce the severity and duration
of symptoms. Resting, drinking plenty of hot fluids, and seeking comfort from over-the-counter cold remedies is still all that can be done to treat most colds.
Keep your immune system in good shape
Whether you actually get sick from a cold after a sufficient amount of the virus has entered your body depends on many factors that affect your immune system. Smoking, stress, poor nutrition and lack of sleep have all been associated with impaired immune function and increased risk of infection.
So, your immune system can be strengthened – and your defences against disease fortified – by eating a well-balanced diet, keeping life stresses to a minimum, avoiding chronic fatigue and obtaining adequate sleep. For weight watchers, immune function is suppressed during periods of very low caloric intake and quick weight reduction, so weight loss should be gradual to maintain good immunity.
Can a walk each day keep the doctor at bay?
People who exercise report fewer colds than their inactive peers. For example, one recent survey revealed that 61% of 700 recreational runners reported fewer colds since beginning to run, while only 4 percent felt they experienced more. In another survey of 170 experienced runners who had been training for 12 years, 90% reported that they definitely or mostly agreed with the statement that they “rarely get sick.”
To test this belief scientifically, two well-controlled studies with young and elderly women were conducted. In both studies, women in the exercise groups walked briskly 35-45 minutes, five days a week, for 12-15 weeks, with the control groups remained physically inactive. The results were in the same direction reported by fitness enthusiasts – the regular walkers experienced about half the days with cold symptoms as the sedentary controls.
Other research has shown that during moderate exercise, several positive changes occur in the immune system. Although the immune system returns to pre-exercise levels very quickly after the exercise session is over, each session represents a boost that appears to reduce the risk of infection over the long term.
A study in Hong Kong
Can too much exercise lower your resistances?
Among elite athletes and their coaches, a common perception is that heavy exertion reduces resistance to colds. During the 1998 Winter and Summer Olympic Games, team doctors reported that “upper respiratory infections abound” and that “the most irksome troubles with athletes are viral infections.” To determine whether these anecdotal reports were true, 2,311 marathon runners who ran the recent Los Angeles Marathon were studied. During the week following the race, one out of seven runners became sick, which was about five times the rate of runners who trained for, but did not run, the Marathon. During the two-month period before the race, runners training more than 60 miles a week doubled their odds for sickness compared to those training less than 20 miles a week. Researchers in South Africa have also confirmed that after marathon-type exertion, runners are at a high risk for sickness. The immune systems of marathon runners have been studied under laboratory conditions before and after running 2-3 hours. A steep drop in immune function occurs lasting at least 6-9 hours. Several exercise immunologists believe this allows viruses to spread and gain a foothold. Overdoing your exercise can lower your resistance and adversely affect your ability to keep the colds at bay.
So, a walk a day really can help keep the doctor at bay!