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Putting Tribex-500 to the Test
Part 1 - Strength and Power Athletes

By Dr. John M Berardi, Ph.D.
First published at www.t-mag.com, Jul 14 2000.

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Come Along for a Ride?

If you read my report last month on the ACSM National Conference, you probably noticed that I didn't mention anything about the research done on Biotest products. You may be wondering why. Maybe it's a cover-up initiated by Biotest! Anyone who speaks of the studies without following strict "talking points" will have mysteriously disappeared, only to wash up on shore some years later, badly decomposed!

Nah, it's nothing like that. I just wanted to do the studies justice because there's clearly more to them than what can be gleaned by a short abstract.
To start off, I want to take you on a little trip. Now slow down, big guy. We're not going to Tijuana. Where we're going is on a trip into the mind of a researcher. Just think of me as your personal tour guide.

And although this trip might not involve nude beaches, Bacardi rum, and all you can eat midnight buffets; I assure you that you'll at least walk away with a bit of a headache. No, not the type of headache you had the morning after you spent half a week's pay buying drinks for yourself and the blonde from Hooters that milked your mammary-minced frontal lobe for all the free liquor and compliments she could get (remember, the one that sent you home alone with $500 less in your pocket?). No, this headache will be a sort of sensory-overload headache. And at least this one is free!

However, like the other headache, this one may also be associated with some pleasant memories (not mammaries, as the case may be).

My goal today is to show you exactly how I critically evaluate scientific data in order to see how it might some how, some way, contribute to bigger biceps peaks and double cross-striated quads; how it might increase bench press strength and decrease body fat. Because you know as well as I do, that there are two things that are always competing for priority in the mind of bodybuilders. The first is the eternal quest for strength, size, and muscularity. The other, well that's usually covered by the atomic dog's ravings about blow-up dolls and fitness models.

It's All About Attitude

To start off, I need to tell you about the attitude you need to adopt when undertaking such a task. And the attitude is this: When it comes to supplement research, skepticism dominates. And as a result of that skepticism, I personally tend to adopt the legal model: guilty until proven innocent. I know, I know. It's not democratic nor does it espouse the ideology of the American judicial system, but so be it. This is my house and I make the rules (insert wicked laugh here)!

Anyway, to get specific, Biotest funded two scientific studies presented at the ACSM meeting, both examining the performance effects of Tribex-500. I've decided to put these two studies under my high-powered scientific microscope and see how good they look at that magnification.

The process will involve evaluating potential publication material and speaking with the researchers responsible for each project in an attempt to find both the strengths and weaknesses in their designs. Remember, guilty until proven innocent! My challenge: to get to the bottom of how good the study designs are and give you, the reader, a glimpse into how to think about evaluating the data that writers often manipulate with less shame than Bill Clinton at a White House intern party.

The Study

The first study and the one I intend to talk about today examined the effects of between 6 and 10 weeks of Tribex supplementation on the muscle size, strength, and body composition of a few male bodybuilders and football players. Weight training, of course, was also incorporated into the study. The individual responsible for putting this project together is someone that I'm sure T-mag readers are familiar with, Dr. Jose Antonio. Dr Antonio is a well-respected and renowned researcher and is well known for his work with muscle hyperplasia and nutritional supplements.

Now before I dive into the study with impunity, let me throw out the old proverb, you can't know a man unless you walk a mile in his shoes. Since I like my shoes, I'm not giving them up to anyone, but I will share one of the coolest things about being in my shoes. Then I'll just let you imagine what walking in them would be like.

One of the perks of my position is that I often get access to unpublished research. In other words, I often get to read about cutting-edge research before the wide world of research and media get their hands on it. Sometimes I even get to read this stuff years before it's public knowledge. I guess it's kind of like dating the hottest girl in town before anyone knows she's hot. I'll admit, I'm a lucky dog.

So, with this said, after reading the preliminary version of the full manuscript that Dr. Antonio has composed and after speaking with him directly, I think that we're ready for take-off.

In this study, 2 football players and 3 recreational bodybuilders (21-24 years of age) were selected to take Tribex every day at a dose of 1 capsule for every 22 pounds of body weight. So, if my math is right, that's about 9 capsules for a 200-pound guy.

The first question to ask is this:

1) What kind of shape were these guys in when they started the study?
If youre wondering why I ask this question, let me explain. If they were in great shape at the start of the study, then it would be very difficult to promote big increases in size and strength. If they were once in good shape, but had been doing nothing but waxing their '78 Gremlins and drinking Bud pounders all summer, the results from a good training and supplementation program could be phenomenal. With that said, bring on the subjects:

As you can see these guys run the gamut from lean to well, not so lean, and from middle weight to heavy weight. One thing to notice though is that they all have pretty respectable strength levels at the start of the study. This is important to keep in mind when we look at the results.

The next relevant questions deal with the supplement.

1) What ingredients does Tribex contain?

Each Tribex capsule (the old formula) contains:

• Tribulus terrestris - 250 mg
• Ipriflavone - 100 mg
• Avena sativa - 100 mg
• Saw Palmetto - 50 mg

*Again, our hypothetical 200-pound male subject would be taking 9 capsules per day, containing a total of 2,250 mg Tribulus, 900 mg Ipriflavone, 900 mg Avena sativa, and 450 mg Saw Palmetto.

2) What is each ingredient proposed to do?

I went directly to Dr. Antonio for these answers:

"Tribulus terrestris is an herbal preparation that supposedly enhances plasma testosterone levels and promotes skeletal muscle hypertrophy.
"Ipriflavone ... has been shown to inhibit osteoclastic (bone degenerative) activity and stimulate osteoblastic (bone regeneration) activity...one could speculate that either singly or synergistically, tribulus and ipriflavone might increase lean body mass or bone mineral content.

"On the other hand, there is no evidence to support the notion that saw palmetto or avena sativa could improve body composition...avena sativa is touted as a remedy for sexual dysfunction despite the lack of peer-reviewed studies...saw palmetto extracts have been shown to improve urinary track symptoms and urinary flow in patients with benign prostatic hyperplasia. "

3) What would one expect to happen if administering this product?

From my discussions with Dr Antonio, I believe that the projected effects of supplementation were an increase in Testosterone, lean body mass, muscle mass, bone mineral content, and an increase in muscle strength.
The men in this study also took part in a bodybuilding program that consisted of a multiple set, split routine. They trained once per day and 4-6 days per week. When looking the program over, the questions to ask are as follows:

1) Is this program the type that would be expected to yield increases in size and strength?

2) Is this program similar to one that most bodybuilders and football players would follow?

The answers to both questions seem to be pretty evident to me. The program sounds like the type that most bodybuilders I know follow.
To evaluate the effectiveness (or lack thereof) of Tribex, Dr. Antonio measured strength by the performance of a 1RM bench press; body composition (which includes weight, fat free mass, fat mass, bone mineral content, and percent fat by skinfolds and DEXA); and muscle torque by a Cybex isokinetic device. These measures were collected directly before the supplementation regimine and directly after.

At this point, it would be appropriate to inquire as to whether these measures have any meaning to bodybuilders and athletes. Again, the answer is a clear yes since these measures are very effective means of evaluating both body composition and explosive power.

Finally, in any training study, it's important to determine initial dietary intake and compare it to final dietary intake to examine whether diet was consistent over the course of the study. If not, any changes could be due to diet and not due to supplementation. We all know that tightening up the diet over the course of a few weeks can dramatically impact performance.
In this study, diet was assessed during the initial and final weeks and the average energy intake was not different from beginning to end. The average daily dietary intakes were as follows:

2,000-3,500 kcal

230-400 g carbohydrate

110-190 g protein (1.3 - 1.9 g/kg)

40-120 g fat

In summary, so far we've seen that we are dealing with pretty well trained men who are following appropriate training protocols and are being assessed with appropriate practical measures.

So what about the results after 6 weeks?

Group Average:

As you can clearly see from the averages, there were very positive changes in body weight (+3 lb), body fat (-1%), lean body mass (+5 lb), and bench press (+18 lb). In addition, measures of bone mineral content and peak leg torque increased as well (data not shown).

Now, although looking at the averages gives us some info about the effectiveness of Tribex, it's also important to look at individual subject data. This is important because if I'm taking Tribex, I don't really care what the average increases of 1,000 Tribex users are--I only care about my own increases. In addition, although the average values might say that there was an average loss of 1% bodyfat, if 4 subjects all gained 1% while 1 subject lost 5%, the average decrease of 1% would not give a good picture of what really happened. Here's the individual data:

So in evaluating the individual data it is clear that:

• 4 subjects increased their body weight while 1 decreased
• 2 subjects decreased body fat while 2 increased body fat and 1 had no change
• All 5 subjects increased lean body mass
• All 5 subjects increased bench press strength

Here's a quote from Dr. Antonio:

"I believe that for trained bodybuilders, Tribex supplementation may be useful for getting you through a plateau. It is evident from the case studies we performed that very well trained athletes can make substantive gains in lean body mass. And you and I know how hard that is for anyone who is trained.... As far as the mechanism (of action) ... I'd speculate that the Ipriflavone might have anabolic effects; it probably has osteogenic (bone generation) effects.... On the other hand, I think these data are also congruent with what you'd expect from a supplement that indirectly affects the hypothalamic-pituitary-gonadal axis."

Someone Hand Me My Microscope

So, bottom line ... Tribex works, right? Well, not so fast! It's time to really examine this study in detail. In other words, lets play devil's advocate and point out the limitations of the project and exactly why it might be premature to say conclusively that Tribex is a miracle supplement. Oh, by the way, if T-mag actually publishes this part of the article, then they've surely got some big ones!

Before we lay into the study design, though, I have to offer a disclaimer. This is the part where I let you know that although many writers ruthlessly make personal attacks at the researchers who conduct studies, I will do no such thing. If science is about data, then evaluate the data, not the scientist. The idiots that try to rip researchers a new one by making slanderous remarks about their work have clearly never attempted a research project of their own. If they had, they would realize both how difficult it is to design a good project and even more so, how difficult it is to carry out even the best study design.

Remember, we researchers have to plan the project and then hope that all the subjects will show up when scheduled and will give their best effort. How often has your training partner missed a workout?

We hope that the subjects will follow regulations such as don't train for X amount of days, don't drink for X amount of days, eat exactly what I say for X amount of days, etc. One little beer wont affect the results will it? OH YES IT WILL!!!

In addition, we have to hope that all the equipment including testing devices, computers, etc. will cooperate with the testing protocol. How often has your computer crashed?

See what I mean?

I hope that now you can start to appreciate what it takes to put together a good project and the difficulties that a researcher faces in doing so. If you only knew how may weeks and months of effort and potential revolutionary data have been lost due to subject non-compliance and equipment failure, you would be shocked.

With all of this said, I'd like to list the limitations of this study and why I think that the results, while somewhat impressive, aren't as clear as they may seem. With any design, we could sit here and criticize all day long, but I would like to address only the major problems.

1 - Subject Characteristics

Earlier I mentioned that an item of major importance is the initial fitness level of the subjects. My major criticism in this regard is that it is hard to determine what level of fitness each subject was at the beginning of the study.

Let me give an example. I have personally been seriously training for about 8 years. As a result, I can handle some pretty respectable weights in the gym. Now, if I were to back off on my training intensity for a few months, my weights would still be pretty good, but I would probably lose a few pounds on my bench press. Put me back on an intense, 10-week training program however, and I'm certain I would be back to "normal."

The same goes for lean mass. I'd probably lose some lean mass by detraining, but after a few weeks of increasing the intensity, the muscle memory would kick in and I'd again be back to "normal."

Therefore, by only looking at before and after supplementation, it's hard to say that subjects were at their "peak" before the study began and that the supplementation helped them break through a plateau. In response to this, Dr. Antonio did comment that: "....gains in lean body mass of this magnitude are unusual in trained athletes." I would tend to agree with this statement if I was certain that the athletes in the study were at a physiologic peak when they began.

2 - No Placebo Control Period

One way to remedy the above criticism would be to take very similar subjects to the 5 tested, and to have them follow the same exact training program without supplementing with Tribex. This would provide a better comparison in order to figure out whether it was the new training and motivation or whether it was the Tribex that boosted body weight, muscle mass, bone mass, and strength.

Without this placebo control period we can't say whether or not it was the training, the Tribex, or the combination of the two that caused the positive changes. Relative to the placebo effect, Dr. Antonio comments that: "Each subject knew that he was taking a supplement that supposedly increased muscle mass. It is possible that subjects trained harder ... in hopes of improving lean body mass."

3 - No Examination of Mechanism

The ideal study would examine the mechanism by which a supplement operates. In this study, the expected increases in body mass, lean body mass, bone mass, and strength, were expected to be caused by potential increases in Testosterone, by increases in bone remodeling, and increases in protein synthesis.

One way to determine whether the gains achieved were due to training, supplementation, a placebo effect, or simply due to chance alone would have been to show that the supplement did what it was expected to. In other words, if Testosterone and protein synthesis went up, then we could speculate that those changes led to changes in size and strength. In the absence of such data, it is hard to say that the changes were due to the supplement.

As Dr. Antonio points out, "the body composition changes were greater than expected for restistance trained subjects ... these results need to be replicated in a similar population of strength-power athletes."

And the Verdict Is....

From speaking with Dr. Antonio, I got the impression that although he recognized the limitations in his study, Tribex seems to be a winner in his mind due to the large effect that was seen after 6*10 weeks of training and supplementation. The limitations of the study design, coupled with my inherently skeptical attitude, prevent me from giving both thumbs up. But I am interested in seeing follow-up work on Tribex in a similar group of men.
Frankly, although the results have not overly impressed me as a scientist, they have peaked my curiousity as a bodybuilder and strength athlete. If there is a supplement that can help well-trained athletes push through training plateaus and increase lean body mass by increments of 5 or 6 pounds, then that is indeed a phenomenal breakthrough in sports nutrition.
If the results seen here can be replicated in a follow-up study with a placebo control group and with some look at mechanism of action, then I'll be the first to forget the hooters and drop my money on a few bottles of Tribex instead.