There are sevearl important ingredients in Pittbull, but the two that have been studied the most are caffeine and gurana. The information below will list information and studies that focus on these two important ingredients.

Caffeine is the most widely used drug in the world. It is consumed daily by millions in coffee, tea, and sodas. We use it for its stimulating effects which are for energy and helps battle fatigue.

Why use Caffeine?

Caffeine has been shown to improve performance, increasing strength output and available energy. Its stimulatory effects improve focus, concentration, and energy levels. This may be especially beneficial prior to a competition or workout. Because caffeine suppresses appetite and aids in the use of fats for fuel.

How does carffeine enhance fat loss?

1. Increase the use of fat as a source of fuel for the body thereby enabling "fat loss"
2. Enhances energy and endurance so that a person can train longer and harder
3. Provide an instant energy boost and improve mental clarity
4. Stimulate the central nervous system which helps overcome fatigue

While most people are pretty familiar with the benefits of caffeine, this popular ingredient has received such negative attention from the media without considering its many positive attributes. Caffeine has been shown in numerous research studies to be effective as a safe stimulant, thermogenic agent, weight-loss aid, and performance enhancer.

How it works:

Caffeine is called a thermogenic agent because it helps speed up our metabolisms or the rate our bodies burn calories. It's also quite obviously a stimulant which is the reason why so many of us use it for work, play, socializing and exercise. Contrary to popular beliefs the effects can be obtained without any of the often-proclaimed negatives.

Caffeine appears to stimulate the adrenal glands to release the hormones epinephrine, norepinephrine (i.e., adrenaline), and the brain messenger dopamine, which in turn enhance fat loss, energy, and endurance, as well as mental clarity. Consuming caffeine before a workout may actually help our bodies use fatty acids for fuel. In other words, caffeine may make our fat-burning workouts even more effective while giving our muscles the extra energy to push just a little harder.

Guarana is basically an herbal form of caffeine. The surprising truth about guarana is that while it may be a valuable aid for temporarily increasing energy levels, its ability to break down and mobilize fat and use it for energy makes it a natural choice for fat loss. Guarana is typically found combined with other "stimulating" herbs to further compound its properties and increase its "fat-burning" effects.

Guarana is an herb that grows within the Brazilian Amazon rainforest. It contains significant amounts of guaranine (the active constituent that's virtually identical to caffeine) and has thus been used for centuries by indigenous tribes to help reduce hunger, relieve fatigue, and treat diarrhea

Like caffeine, guarana works by stimulating the adrenal glands to release the hormones epinephrine, norepinephrine (a.k.a. adrenaline), and dopamine, which in turn enhance fat loss, energy, and endurance as well as mental clarity.

Serving Size: 2 capsules

Container: 120

Proprietary Blend 1010mg
Guarana 400mg
Citrus Aurantium 300mg
Bioperine 5mg
Green Tea Extract 200mg
Chromium Polynicatinate 300mcg
Ginseng 200mg
B-Complex 1000mcg
Alpha Lipoic Acid 100mg

*Please don not take this supplement if you have high blood pressure.

The research on caffeine or gurana alone seems to show that these ingredients, without ephedra, do not support weight loss unless a person is exercising. What I have found from my personal experience is that coupled with exercise, a person is a lot more likely to burn more calories during cardio and weight training with caffeine compared to without caffeine - thereby this person can burn more total calories after a workout.

Here is one study that supports the thermogenic effect of caffeine.

First Department of Internal Medicine, Kyoto Prefectural University of Medicine, Japan.

To clarify whether there were any differences in basal metabolic rate (BMR) and thermogenic response to caffeine in individual obese women, and if so, whether such differences affected weight loss, the basal and resting metabolic rates at 30 min after a caffeine loading test (4 mg/kg ideal body weight, per os) were measured in 136 obese women and ten lean age-matched controls. The obese subjects were then asked to follow a combined low calorie diet and exercise regimen. There were no differences in the BMR and thermogenic responses to caffeine between the obese and lean groups. However, the BMR and the thermogenic responses to caffeine varied widely in obese subjects. After two months of treatment, body weight and percentage body fat in obese women were significantly (P < 0.001) reduced. There were significant correlations between the BMR and body weight loss (r = 0.3621, P < 0.001), between BMR/lean body mass and body weight loss (r = 0.3196, P < 0.001) and between the thermogenic response to caffeine and body weight loss (r = 0.6943, P < 0.001). When the criterion of a BMR less than 3.10 kJ/min (less than two standard deviations below the mean of the age-matched lean control) was used to define an obese group with reduced BMR, there were 30 obese subjects in this group, and their body weight was significantly decreased by treatment.

Relevant Studies

Costill, D.L., et al., "Effects of Caffeine Ingestion on Metabolism and Exercise Performance," Med Sci Sports 10.3 (1978) : 155-8.

Doherty, M., "The Effects of Caffeine on the Maximal Accumulated Oxygen Deficit and Short-Term Running Performance," Int J Sport Nutr 8.2 (1998) : 95-104.

Johnson-Kozlow, M., et al., "Coffee Consumption and Cognitive Function Among Older Adults," Am J Epidemiol 156 (2002) : 842-50.

Nehlig, A., and Debry, G., "Caffeine and Sports Activity: A Review," Int J Sports Med 15.5 (1994) : 215-23.

Pasman, W.J., et al., "The Effect of Different Dosages of Caffeine on Endurance Performance Time," Int J Sports Med 16.4 (1995) : 225-30.

Spriet, L.L., "Caffeine and Performance," Int J Sport Nutr 5 (1995) : S84-99.

Wager-Srdar, S.A., et al., "Thermoregulatory Effects of Purines and Caffeine," Life Sci 33.24 (1983) : 2431-8.

Andersen, T., and Fogh, J., "Weight Loss and Delayed Gastric Emptying Following a South American Herbal Preparation in Overweight Patients," J Hum Nutr Diet. , Jun;14.3 (2001) : 243-50.

Bempong, D.K., and Houghton, P.J., "Dissolution and Absorption of Caffeine from Guarana," J Pharm Pharmacol 44.9 (1992) : 769-71.

Benoni, H., "Studies on the Essential Oil from Guarana," Z Lebensm Unters Forsch 203.1 (1996) : 95-8.

Galdur'oz, J.C., and Carlini, E.A., "The Effects of Long-Term Administration of Guarana on the Cognition of Normal, Elderly Volunteers," Rev Paul Med 114.1 (1996) : 1073-8.

Morton, J.F., "Widespread Tannin Intake Via Stimulants and Masticatories, Especially Guarana, Kola Nut, Betel Vine, and Accessories," Basic Life Sci 59 (1992) : 739-65.

Relationship between basal metabolic rate, thermogenic response to caffeine, and body weight loss following combined low calorie and exercise treatment in obese women.Int J Obes Relat Metab Disord. 1994 May;18(5):345-50. Yoshida T, Sakane N, Umekawa T, Kondo M.