Caffeine - Do you need it?
A staggering 2.5
billion cups of coffee are drunk world wide every day. This makes caffeine the
world's most popular stimulant. It is a drug, not a nutrient and the 115mg in
an average cup of coffee is quickly absorbed into you bloodstream. Within 15
minutes of sipping a single espresso, you are feeling the effects. Caffeine
works directly on the brain by stimulating the release of two stress hormones, cortisol
and adrenalin. It also causes your muscles to tighten and a slight increase in
heart rate and blood pressure. As a potent diuretic, caffeine causes your
kidneys to produce more urine. These effects are tolerable on a small scale,
but too much caffeine in a day (over 500mg for most people) will drain your
energy, wreck your sleep patterns and add to your stress levels. Most people
are not short of regular doses of adrenalin and cortisol charging their system
as a response to stress - so reaching for a coffee to help you cope with stress
is crazy!
Caffeine remains
in the system for around 4-6 hours in most people. But an individual isn't most
people and we are all very different when it comes to how we handle caffeine.
Smokers metabolise and break down caffeine faster compared with non-smokers so
they feel the need for their next fix sooner. My own research, on the benefits
of giving up caffeine, revealed dramatic changes in mood and energy levels.
Individuals working offshore on Shell's oil platforms reported fewer headaches
and better sleep habits as a result of giving up caffeine.
Regular drinkers
develop a tolerance to caffeine and do not get the same "buzz" as
usual, but suffer from withdrawal symptoms if they don't get the drug. The
"need" for a cup of coffee is simply to neutralise the withdrawal
symptoms (which include headaches, muscle and joint aches and short temper).
These are what you can expect when you actively give up caffeine, and can last
up to 3 days in some people. Don't reach for a headache tablet during this
withdrawal phase since many contain caffeine. But the rewards of getting
through this phase are great. With caffeine out of your system, you are likely
to sleep better and have more energy.
Caffeine occurs naturally in coffee, tea,
cocoa (used to make chocolate) and guarana (a herb often added to energy drinks
and bars).
It is added to
Colas and other soft drinks such as Lucozade, Iron Bru and Red Bull. There is a
new drink from America called "Jolt" which contains
twice the caffeine content of a can of Coke.
That's the story
at rest but, in the world of athletics, caffeine has been shown to increase
power, speed and endurance. Recent research revealed that runners were able to
keep going for an amazing 41 minutes longer with caffeine tablets compared with
the same amount of caffeine in coffee or decaf with pure caffeine added. This
is because coffee contains a cocktail of substances, which may interfere with
caffeine metabolism making it less effective than the pure drug. Caffeine can
benefit endurance performance by stimulating the release of free fatty acids.
This encourages muscles to use fat as a fuel, thus sparing the limited glycogen
supplies.
Caffeine also benefits shorter term exercise of 30 - 60 minutes
when there is still plenty of glycogen in muscles. In this situation, it is the
stimulating effect on the brain which may boost performance. Individuals have a
reduction in perceived exertion. Caffeine acts directly on muscles to increase
the free calcium in the muscle cells and reduce the amount of potassium. Both
have a positive effect on endurance. The amount needed to produce these effects
is around 300mg - equivalent to 2 "mugs" of strong coffee. But before
you reach for the Nescafe, these research findings were carried out in
laboratory conditions, using highly trained athletes. It is likely that the
effects during competition (when adrenalin levels are high anyway), or weekend
cyclists would be much less. Nevetheless, the drug is considered a performance
enhancing substance and its use is restricted (rather than banned) by the IOC.
The permitted amount is 12 microgrammes per millilitre in urine. You would need
to take 1,200mg to reach this level - an amount which would cause severe
stomach pains and muscle tremors (so no good for archers or clay pigeon
shooters!). The only good news is that exercise over-rides the diuretic effects
of caffeine - provided you gulp down your coffee, get on your bike and go.