Supplement Performance - Jolt Gum Increases Performance and Enhances Testosterone

 By Robbie Durand, M.A.

Senior Science Editor

            As many of you know from the research articles I have written for MD, I am a huge proponent of caffeine for enhancing performance in the gym. I don’t recommend nonstop caffeine use, as you will rapidly grow desensitized to its effects— but a jolt of caffeine before your next leg workout may be just what you need for a monster training session.

            A growing body of evidence suggests that caffeine works to enhance short term, high-intensity contractions by blocking the adenosine receptor and by enhancing neuromuscular excitation. Caffeine is similar in structure to adenosine— it easily crosses the blood-brain barrier and binds to adenosine receptors, blocking their action. If you were to give someone a dose of adenosine, he would get very sleepy— as adenosine levels in the brain rise during the evening, which promotes sleep. A reduction in adenosine activity could result in better training sessions, as reduced adenosine results in greater muscular recruitment and reduced pain perception— what more could a bodybuilder want during a workout?

            A study conducted in 2002 found that chewing your caffeine may be better and result in higher absorption than taking caffeine pills. The study found that compared to caffeine tablets, caffeine gum had higher absorption rates— as it’s absorbed through the buccal mucosa, thereby bypassing the digestive tract and liver degradation. In an earlier “Bodybuilding Science” column, I reported on a study that found that caffeine administration enhanced testosterone production during resistance exercise— and it also increased cortisol levels. It’s almost a double-edged sword for bodybuilders!

            Researchers have yet to explore the impact of caffeine chewing gum on performance. Scientists from New Zealand administered caffeine to cyclists as an absolute dose (240 mgs) by giving them six pieces of commercially available Jolt (spearmint flavored) caffeine chewing gum—or the same flavor in a placebo (Wrigley gum). After 10 sprint tests, the cyclists who received the caffeine gum had substantial improvements in performance by reducing fatigue. Another interesting finding was that testosterone increased by ~12 percent in the caffeine chewing gum group, whereas cortisol decreased ~21 percent relative to the placebo group. 

            So the question I am sure you are asking is, “Why did cortisol decrease in the latter study and increase in the former study?” The researchers speculated it was the doses used in the studies—researchers used 240 mgs in the latter study, whereas in the former study, subjects consumed 800 mgs of caffeine.

            The use of caffeine gum may be something that bodybuilders may want to explore. Caffeine is absorbed more rapidly from chewing gum than from pills, and at lower doses seems to have a beneficial impact on the testosterone to cortisol ratio— whereas at higher doses, it seems to have diminishing returns.

Reference:

            Paton CD, Lowe T, Irvine A. Caffeinated chewing gum increases repeated sprint performance and augments increases in testosterone in competitive cyclists. Eur J Appl Physiol, 2010 Aug 25. [E-pub, ahead of print]

Naringenin Enhances Fat Loss

            A couple of years ago, the National Inquirer had this headline on the cover: “The Grapefruit Diet: Lose 50 Pounds!” Many people might laugh at the thought of a grapefruit being a tool for weight loss, but researchers from the Hebrew University of Jerusalem and Massachusetts General Hospital (MGH) reported that naringenin, the active component found in grapefruit and other citrus fruits, may cause the liver to break down fat while increasing insulin sensitivity— a process that naturally occurs during long periods of fasting.

            Naringenin activates a family of small proteins, called nuclear receptors, causing the liver to break down fatty acids. In fact, the compound seems to mimic the actions of other drugs, such as the lipid-lowering Fenofibrate and the anti-diabetic Rosiglitazone, offering the advantages of both. Researchers found that naringenin increases two important pharmaceutical targets, PPAR-alpha and PPAR-gamma, while blocking a third, LXR-alpha.

            Naringenin causes physiological changes in genes similar to that of fasting. The liver is the main organ responsible for the regulation of carbohydrate and lipid levels in the blood. Following a meal, the blood is flushed with sugars, which activate LXR-alpha, causing the liver to create fatty acids for long-term storage. During fasting, the process is reversed— fatty acids are released by fat cells, they activate PPAR-alpha in the liver, and are broken down to ketones. A similar process, involving PPAR-gamma, increases sensitivity to insulin. Lead researcher Martin L. Yamush commented, "Naringenin causes a process which is similar to the Atkins diet, without many of the side effects.”

            Taking naringenin causes the liver to behave as if it’s fasting— breaking down fatty acids instead of carbohydrates. Adding naringenin to your supplement stack while you are trying to get ripped can enhance fat loss.

Reference:

            Goldwasser J, Cohen PY, Yang E, Balaguer P, Yarmush ML, et al. Transcriptional Regulation of Human and Rat Hepatic Lipid Metabolism by the Grapefruit Flavonoid Naringenin: Role of PPARa, PPARc and LXRa. PLoS ONE, 2010 5(8).