Four Supplements to Jump Start Your Metabolism

Caffeine
Caffeine is in my opinion the ‘king of thermogenics.’ In conjunction with other thermogens (e.g. bitter orange) it may be even more effective! A single-dose of 100 mg caffeine increased the resting metabolic rate of human volunteers by 3-4% over 2 hour and 30 minutes; interestingly, if you combine caffeine (in coffee) with some bitter orange, your peak metabolic rate can go as high as 30%. Talk about turning up your metabolic furnace.1 Also, if you take caffeine repeatedly (100 mg) at 2-hour intervals over a 12-h day period can increase energy expenditure by 8-11% during that period. This translates into an extra 150 calories burned by the lean subjects and 79 calories in the obese subjects. So if we took the ‘average’ increase as 100 calories, just for the sake of this example, if you had a net increase in 100 calories, seven days a week, for an entire year, that would theoretically result in a 12 pound weight loss. Is there a difference in caffeine response between those who exercise and those who do not? Ten men who were endurance trained were compared to 10 who were sedentary. Caffeine consumption resulted in a greater RMR or resting metabolic rate increase in the inactive subjects than in exercise-trained subjects. No significant differences were observed in RMR response between regular or non-regular consumers of caffeine. 2 In fact, it makes sense that endurance-trained individuals, who also tend to be smaller and lighter, would have a blunted response. The endurance-trained body is trying to conserve what precious little body mass (and muscle mass) it has left. So they probably do not want to have an enormous thermogenic response to a caffeine challenge. The bottom line on caffeine? Pretty easy, it’s safe, it’s effective for enhancing exercise response, and effective for helping you burn fat.
Commonly used dose – 300 mg daily

Yohimbe
Yohimbe comes from the bark of an African tree. Its active ingredient is called yohimbine. A purified extract from yohimbe bark produces an alkaloid (with stimulant properties like caffeine and ephedra) called yohimbine, which is regulated as a prescription medication and used for treating erectile dysfunction or ED in males.3 Also promoted as a male aphrodisiac and a natural form of Viagra.Yohimbine’s main effects are lipolysis (or fat splitting). Some have also suggested that it has mild appetite suppressive effects. Administered prior to exercise, it boosts lipolysis and serum free fatty acid levels both during and following exercise. Perhaps there is also a synergistic effect of yohimbine and caffeine. Pre-exercise yohimbine administration has the potential to down-regulate the lipoprotein lipase activity of visceral adipocytes, increase lipolysis in refractory gynoid fat depots, and improve the impaired lipolytic response to exercise in the elderly.4 I know, you’re scratching your head. That basically means that yohimbine has great potential for fighting fat accumulation. One study found that oral yohimbine administration (0.2 mg/kg) induced fat breakdown in fasting women without an effect on plasma glucose, insulin levels, heart rate or blood pressure during the time-course of the experiment (240 min). Plasma norpinephrine (but not epinephrine) concentrations were increased (100 percent) after oral yohimbine administration. The lipid-mobilizing effect of yohimbine in women is mainly attributable to the increase in synaptic norepinephrine (this is basically a hormone that ‘jacks you up’) with a resultant increment in lipolysis or fat breakdown.5
Common used dose – 10 mg daily

Bitter Orange (also known as Sour Orange and Citrus Aurantium)
The main use for bitter orange is for appetite suppression and thermogenesis. The primary active in bitter orange is synephrine. Interestingly there are six possible isomers (different forms of the same molecule) of synephrine (para, meta, ortho; and for each a d or l form). One product purportedly containing synephrine alkaloids from bitter orange contains both p-synephrine and m-synephrine. Currently, there are actually few studies on bitter orange alone and its effects on metabolism and body composition. Typicall, you might find bitter orange combined with caffeine and other ingredients.6 Nonetheless, anecdotal reports of those who use bitter orange containing supplements suggest that it is less effective then ephdra plus caffeine but can still indeed produce a weight loss benefit.
Commonly used dose – 5-20 mg daily

Green tea extract
Green tea; besides a billion Chinese who drink the stuff and a few tree-hugging types, you must be thinking, there’s gotta be something to this stuff. Well, what if I told you that green tea could jack up your metabolism, help you exercise better, decrease your risk of cancer, and walk your dog? Okay, 3 out of 4 ain’t bad. Green tea, next to coffee, is in essence a ‘functional beverage’ in its own right. The proof is in the tea bag. For instance, we know that green tea contains a high level of polyphenolic compounds known as catechins. Thus a group of scientists studied the effects of green tea extract (GTE), which is rich in catechins, on endurance capacity, energy metabolism, and fat oxidation in mice over a 10-wk period. Swimming times to exhaustion for mice fed GTE were prolonged by 8-24%. The effects were dose dependent and accompanied by greater increases in fat oxidation or burning. In addition, feeding with GTE increased the level of beta-oxidation activity in skeletal muscle (another indicator of better fat burning). Plasma lactate concentrations in mice fed GTE were significantly decreased after exercise with simultaneous increases in free fatty acid concentrations in plasma (blood). According to this study, GTE is beneficial for improving endurance capacity and support the hypothesis that the stimulation of fatty acid use is a promising strategy for improving endurance capacity.7

Did you also know that a substance called theanine is present in GTE? Theanine, a specific glutamate derivative in green tea, decreases doxorubicin (DOX)-induced adverse reactions such as the induction of the lipid peroxide level and the reduction of glutathione peroxidase activity in normal tissues. In English, that means theanine lessens the adverse reactions involved in oxidative damage. Meaning, GTE can further maintain the health of your cells.8

Even when you examine severely damaged muscles, you’ll see that GTE can be of benefit. For instance, Duchenne muscular dystrophy is a severe X-linked muscle disorder characterized by lethal muscle wasting due to the lack of a protein called dystrophin. In one study, investigators tested whether the antioxidant properties of GTE could diminish muscle necrosis (i.e. death) in the mice with muscular dystrophy. A diet supplemented with 0.01% or 0.05% green tea extract was fed for 4 wk beginning on the day of birth. This feeding regimen significantly and dose-dependently reduced necrosis in the fast-twitch muscle elongator digitorum longus but at the doses tested had no effect on the slow-twitch soleus muscle. This means that the more GTE they gave, the more it protected fast twitch muscle fibers (but not slow twitch muscle fibers). The approximate effective dose in humans is about 7 cups of green tea per day. If you want to extrapolate this data, certainly it makes sense that if you are a tea drinker, then going ‘Green’ is the only way to go!9
Commonly used dose - 125-500mg/day

Summary: Caffeine, Green tea, Yohimbine, and Bitter Orange are commonly used thermogens. A combination of each in moderate doses may achieve weight loss results via enhanced metabolic rate, lipolysis as well as their general stimulant effect on the nervous system (i.e. acts as a wake me up for the brain).

(Read these if absolutely necessary)
1. Mendel RW, Hofheins JE, and TN Ziegenfuss. Effect of JavaFit Extreme on Metabolic Rate, Substrate Utilization, and Cardiovascular Safety. Abstract: International Society of Sports Nutrition Conference, 2004. www.sportsnutritionsociety.org
2. Poehlman ET, Despres JP, Bessette H, Fontaine E, Tremblay A, Bouchard C. Influence of caffeine on the resting metabolic rate of exercise-trained and inactive subjects. Med Sci Sports Exerc. Dec 1985;17(6):689-694.
3. http://www.supplementwatch.com/supatoz/supplement.asp?supplementId=305
4. McCarty MF. Pre-exercise administration of yohimbine may enhance the efficacy of exercise training as a fat loss strategy by boosting lipolysis. Med Hypotheses. Jun 2002;58(6):491-495.
5. Berlan M, Galitzky J, Riviere D, et al. Plasma catecholamine levels and lipid mobilization induced by yohimbine in obese and non-obese women. Int J Obes. May 1991;15(5):305-315.
6. Allison DB, Cutter G, Poehlman ET, Moore DR, Barnes S. Exactly which synephrine alkaloids does Citrus aurantium (bitter orange) contain? Int J Obes Relat Metab Disord. Feb 8 2005.
7. Murase T, Haramizu S, Shimotoyodome A, Nagasawa A, Tokimitsu I. Green tea extract improves endurance capacity and increases muscle lipid oxidation in mice. Am J Physiol Regul Integr Comp Physiol. Mar 2005;288(3):R708-715.
8. Sugiyama T, Sadzuka Y. Theanine, a specific glutamate derivative in green tea, reduces the adverse reactions of doxorubicin by changing the glutathione level. Cancer Lett. Aug 30 2004;212(2):177-184.
9. Buetler TM, Renard M, Offord EA, Schneider H, Ruegg UT. Green tea extract decreases muscle necrosis in mdx mice and protects against reactive oxygen species. Am J Clin Nutr. Apr 2002;75(4):749-753.

 

---