Herbal supplements – sport supplements part 7 (herbal – part 1 of 2)
Herbs in their natural form have been used medicinally for centuries, and extracts of many of these are widely used in modern complementary and alternative medicine. Many of the claims made for them are useful for athletes, especially with regards to weight control and fat loss and consequently we are seeing more and more appear in sport shops. Even though there are comparatively few herbal sport supplements, there is still a great number available; in this article (and the next, herbal part 2) we concentrate on some of the more popular ones, but no doubt there will be disagreement as to what these should include. The herbal extracts in this and the next article are considered only as single supplements, but we shall return to some of them in a later article about Combined supplements.
In general, there is concern by the medical world about the efficacy and safety of most herbal-extract supplements, or even natural forms, be it for medicinal purposes, weight control or as ergogenic aids. Adverse effects are common, and since most herbal supplements come combined with other herbs or chemicals for which no scientific data is available, using them might be an unnecessary risk; the weight loss products are perhaps the ones most associated with adverse side-effects. Moreover, many herbal supplements contain banned substances, so it is best to seek the advice of a sport physician before using them.
is the active ingredient of chillies, and capsinoids (naturally present in chillies, with a similar molecular structure to capsaicin) are claimed to be especially useful for weight management and fat loss. There is evidence to support this: a 2010 study concluded that capsinoids may be an effective weight-loss aid, in addition to diet and exercise. However, an earlier study showed its potential to deplete glycogen stores during exercise, even at rest, which may adversely affect an athlete’s performance. Therefore, if you need to lose fat and improve your performance, then you can probably choose better than either of capsaicin or capsinoids.
is a plant that grows in India and has a long and well-established use in Ayurveda, a traditional Hindu system of medicine. It is theorised that forskolin, or forskolin extract, can stimulate fat metabolism but studies have been incompatible; some showing improvements in body composition, and some showing no effect whatever. Until more evidence comes to light the benefits of forskolin regarding weight control and fat loss remain inconclusive.
is the insoluble fibre that comes from konjac, a plant native to eastern Asia, and is known mainly for promoting weight loss. Studies have consistently shown that glucomannan supplementation can induce significant bodyweight reduction via fat loss in overweight and obese (but otherwise healthy) individuals, and seems to be well-tolerated. An eight-week study in 2007 of overweight men and women showed a reduction in fat mass by 1.0-3.9kg and 1.4-6.4kg in men and women, respectively, without exercise; and 1.2-4kg and 2.5-4.7kg in men and women, with exercise – LDL cholesterol levels also dropped significantly. Whether it is effective for non-overweight individuals is not certain. The suggested dosages below are those that have produced positive results in fairly recent studies:
Glucomannan: suggested dosage of between 2g and 4g a day
Glucomannan is a natural laxative, so it is not advisable to have it just before bedtime, close to exercise time or any time close to an athletic event. Some have also complained that it caused choking and/or blockage of the throat, oesophagus or intestine, so it is better to take it with about 200ml of water.
Green tea extract
is 90-per-cent a chemical compound, known as green tea catchins, from the dried leaves of the tea plant, Camellia sinensis. Apart from many medicinal uses, it is often touted for its weight management properties. It is believed that green tea catechins influence the sympathetic nervous system (nerves near the middle part of the spinal cord, supplying the internal organs, blood vessels and glands), such that it increases energy expenditure and fat oxidation. It is still unclear whether green tea catechins help athletic performance, but there is much evidence to support claims that it helps to reduce body fat.
The drop in overall body mass and fat percentage are significant; in one Chinese study in 2008, the subjects lost about 0.7kg and 0.6 per cent, respectively, during a 90-day trial. However, it is unclear for how long, and how much, such benefits will continue. In trials that showed a loss in body fat, the intake dosage varied considerably, but as they seemed to have been well-tolerated the range is given below:
– Green tea extract (catechins): 270mg to 1200mg a day
Nonetheless, if you have any conditions that are known to be aggravated by caffeine (such as palpitations) then you should not take any green tea supplements without first consulting a doctor. These doses are very high, so even if you have no known intolerance to caffeine you should not take more than the lowest dose suggested (270mg a day), and this may already be higher than those suggested on commercial products. In one cup of green tea the amount of caffeine is normally between 20g and 50mg, yet there are supplements available that contain five or ten times this amount in just one capsule.
You can find more information about sport nutrition here!