Choline

Movement of a limb is achieved by exciting a muscle so that it contracts. Muscles do not contract of their own accord; they rely on messages from the brain via nerves.

How do nerves tell muscles to contract?

A signal is transmitted from the brain to the end of the nerve attached to the muscle that it wishes to contract. There is a small space between the end of the nerve and the muscle and it is across this neuromuscular space that the nerve pushes small quantities of a chemical called acetylcholine. When sufficient acetylcholine attaches to the outer surface of the muscle cell, the muscle cell becomes excited and contracts. Should you run out of acetylcholine then the muscles will not be able to contract, even if they are adequately stocked with energy (ATP).

Physiologists reckon that acetylcholine is actually broken down inside the neuromuscular junctions during prolonged exercise. Nerve cells then "grab" the choline floating by in the blood, using it to make new acetylcholine and as a result, your blood choline levels start decreasing. Naturally, if your choline levels fall too far, acetylcholine production can come to a relative standstill, and your nerve cells will simply refuse to stimulate your muscles.

What is the function of Choline?

Choline is a vitamin like compound that is an essential part of the human diet as it is used by the body to produce acetylcholine. Without choline, acetylcholine cannot be produced and the body cannot function normally. Choline is also an extremely important structural element of cells, especially cell membranes, and is essential for the process of breaking down fat for energy.

Choline and the 'Wall'

When you run a race like the 5km, 10km or half-marathon the choline concentrations remain sufficient. It appears that your choline levels drop dramatically only when you run a marathon or exercise continuously for approximately two hours or more. Some exercise scientists believe that this drop in choline is behind the devastating fatigue which strikes near the end of a marathon - referred to, by many marathon runners, as the 'Wall'.

Some scientists reason that choline supplements if taken at the right time and in the right amount might help the nervous system continue to stimulate muscle cells and keep you striding toward the marathon finish line at your desired pace.

Where does choline come from?

Choline is available in foods such as: liver, cauliflower, soybeans, spinach, lettuce, nuts, and eggs. The bottom line is that even a choline rich natural diet probably would not prevent the drop in blood choline levels that happen after 20 miles or so of marathon running.

For a marathon, how much and when?

The right amount is probably about 2.5grms, swallowed about an hour before your marathon begins. This additional dosage of choline in your blood may begin to fall three hours after you have taken it (e.g. two hours into your marathon), so it perhaps makes sense to take another 2.5 gram dose at the 10 to 13 mile point of your race.

Are there any side effects?

Choline is perfectly safe to take, the only potential problem being an occasional bout of diarrhea or some foul flatulence.

Supplements, vitamins and minerals

Body Building & Weight Loss Supplements

High quality bodybuilding and weight loss supplements, vitamins and minerals, as well as other health and nutritional products.

Select this link for more information on "Bodybuilding and Weight Loss Supplements".

Associated Pages

The following Sports Coach pages should be read in conjunction with this page:

Associated Books

The following books provide more information related to this topic:

  • Advanced Studies in Physical Education and Sport, P Beashel et al., ISBN 0 17 4482345
  • Physical Education and the Study of Sport, B. Davis et al., ISBN 0 7234 31752
  • Essentials of Exercise Physiology, W.D. McArdle et al., ISBN 0 683 30507 7
  • Physical Education and Sport Studies, D. Roscoe et al., ISBN 1 901424 20 0
  • The World of Sport Examined, P. Beashel et al., ISBN 0 17 438719 9
  • Advanced PE for Edexcel, F. Galligan et al., ISBN 0 435 50643 9
  • Examining Physical Education, K. Bizley, ISBN 0 435 50660 9
  • Sport and PE, K Wesson et al., ISBN 0 340 683821
  • PE for you, J. Honeybourne, ISBN 0 7487 3277 2