Exercise has been shown to improve immunity, making you less likely to get sick. Just remember that solitude and stillness are just as powerful, and they've been keeping people well for thousands of years.
Sometimes salvation lies in extremes. There's nothing like combining a day of say, white-water kayaking followed by a symphony concert and a moonlit walk on the beach to make you feel alive.
Fighting stress works much the same way. When you're fit, your body clock may wake you at 5 am, urging you to tie on those running shoes and get onto the road. It's your body's way of demanding its dose of endorphins. That measured, well-practiced routine of say, running or rowing can feel very reassuring.
High action clears the mind
Then there's a time to erupt into high-intensity action, like doing some sprints. That sadistic PE instructor at your school may have had the IQ of a geranium, but he was right about one thing: those punishing walk-jog-sprint routines get the blood pumping. They also clear the mind – of course his was clear to start with.
You don't need to go free-fall skydiving every time you want a high-intensity workout. A spinning class, some sprints in the pool, a punishing bike ride or hammering away at a heavy bag will all have the same effect.
After all that, find yourself a mountain with some oddly shaped stones, a pergola and Chinese lantern. Failing that, somewhere quiet where phones don't ring and Donald Trump doesn't appear on TV wearing his ginger stoat.
Meditation boosts your immune system
A recent study in the journal Psychosomatic Medicine found that a group of people who participated in an eight-week meditation training programme had a stronger immune system that those who didn't meditate.
The study consisted of 48 men and women, of whom half were randomly selected to participate in three-hour mindfulness classes. The other half of the participants in the group were told they were on the waiting list.
The subjects' brain waves were then measured. The researchers did this because there's an increase in electrical activity in the front left portion of the brain when anxiety levels are low and you experience positive emotions.
Electrical activity was also measured while the subjects did things like write about positive and negative experiences. At the end of the eight-week test, all the subjects were given a flu vaccine and then their immune responses were gauged by measuring the antibody levels their immune systems produced.
Positive thoughts – strong immune system
The half of the group that meditated had the most electrical activity in the front left portions of the brain – indicating the most positive emotions – and they also had the strongest immune response.
It's still not completely understood why meditation is so good for the immune system, but it seems to be linked to the deep rhythmic breathing that accompanies the meditative state. Deep breathing stimulates the circulation of the body's lymphatic system, and getting the lymph fluid moving helps remove toxins from the body.
So do enough high-energy activity, combined with deep breathing, and you might be able to stand the sight of Mr Trump without raising a sweat, or even your heartbeat. – (William Smook, updated June 2009)