Why do they say the the longer...

BuddyBoy

Got any Ice Cream?
You use ECA.. the better it works?

has anyone else heard this?

Whats the reasoning behind it?
 
From:

Pharmacological Approaches to Fat Loss: Targeting Beta-Adrenergic Receptors
by by Bryan Haycock, MS, CSCS

http://www.mesomorphosis.com/articles/haycock/ephedrine-and-beta-adrenergic-receptors.htm



...First, although ephedrine binds to other adrenergic receptors, it seems that the most beneficial adrenergic effects, such as thermogenesis, are actually enhanced after chronic use.2,3 This may be explained by chronic stimulation of alpha receptors by NA and Adr. This chronic alpha-adrenergic stimulation may activate thyroxin deiodinases leading to the peripheral conversion of T4 to T3. In fact, significant increases in the ratio of T3 to T4 have been shown to occur after 4 weeks of chronic treatment of ephedrine.2 Increased levels of T3 can sensitize adrenergic sensitivity to NA and Adr. It should be noted that the same study showed that this ratio decreased below initial values after week 12 of treatment.

Another explanation of its increased efficacy after chronic treatment is it’s interaction with the beta-3 receptor. Although the exact structure and function of this receptor is still being explored, it is almost certain that at least 40% of ephedrine’s actions are due to it’s effect on beta-3 receptors.6 A study done to explore this used a beta-1 and beta-2 antagonist called nadolol. Nadolol was administered concomitantly with ephedrine to healthy volunteers. Nadolol completely inhibited changes in heart rate and plasma glucose due to it’s blockade of beta-1 and beta-2 receptors. However, the thermogenic effect of ephedrine was still at about 43%. This means that at least 40% of ephedrine’s thermogenic effects are due to beta-3 activation. This alone does not explain ephedrine’s effects after long term use. What does explain this is the desensitization properties of the beta-3 receptor. Beta-3 receptors lack most of the structural properties that are responsible for beta-2 receptor desensitization.7 So even after ephedrine fails to have significant effects on the beta-2 receptor, it would potentially continue to stimulate adenylate cyclase activity by virtue of its effect on the beta-3 receptor...
 
T3 to T4 ratio drops below baseline after 12 weeks so maybe you should consider cycling off every 2-3 months.


Am J Clin Nutr 1985 Jul;42(1):83-94 Related Articles, Links


Enhanced thermogenic responsiveness during chronic ephedrine treatment in man.

Astrup A, Lundsgaard C, Madsen J, Christensen NJ.

The thermogenic effect of a single oral dose of ephedrine (1 mg/kg body weight) was studied by indirect calorimetry in five women with 14% overweight before, during and 2 mo after 3 mo of chronic ephedrine treatment (20 mg, perorally, three times daily). Before treatment and 2 mo after its cessation a similar thermogenic response to ephedrine was observed. The total extra consumption of oxygen was 1.3 1 before and 1.2 1 after cessation of the chronic treatment. After 4 and 12 wk of treatment ephedrine elicited a more sustained response, the extra oxygen consumption in the 3 h following ephedrine intake being 7.0 and 6.9 1, respectively. The ratio of serum T3 to T4 increased significantly after 4 wk of treatment (15.6 +/- 1.3 vs 19.4 +/- 2.4; p less than 0.05), but decreased below the initial value after 12 wk treatment. The mean body weight was significantly reduced after 4 and 12 wk of treatment (2.5 and 5.5 kg, respectively). An improved capacity for beta-adrenergic induced thermogenesis may be useful in the treatment of obesity.
 
In some studies it was used for > 20 weeks...

Int J Obes Relat Metab Disord 1993 Feb;17 Suppl 1:S69-72 Related Articles, Links


Safety and efficacy of long-term treatment with ephedrine, caffeine and an ephedrine/caffeine mixture.

Toubro S, Astrup AV, Breum L, Quaade F.

Research Department of Human Nutrition, Royal Veterinary and Agricultural University, Fredriksberg, Copenhagen, Denmark.

In a randomized, placebo-controlled, double blind study, 180 obese patients were treated by diet (4.2 MJ/day) and either an ephedrine/caffeine combination (20mg/200mg), ephedrine (20mg), caffeine (200mg) or placebo 3 times a day for 24 weeks. 141 patients completed this part of the study. All medication was stopped between week 24-26 in order to catch any withdrawal symptoms. From week 26 to 50, 99 patients completed treatment with the ephedrine/caffeine compound in an open trial design, resulting in a statistically significant (p = 0.02) weight loss of 1.1kg. In another randomized, double-blind, placebo-controlled 8 week study on obese subjects we found the mentioned compound showed lean body mass conserving properties. We conclude that the ephedrine/caffeine combination is effective in improving and maintaining weight loss, further it has lean body mass saving properties. The side effects are minor and transient and no withdrawal symptoms have been found.
 
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