Anecdotes, placebos, dosing, and controlled studies.

Common flaws/fallacies in claims accompanying many performance enhancing products include:

• absence of a comparison, or "control", group of comparable age and training status undertaking exactly the same exercise protocol but with an inert or inactive agent. Thus the findings lack a valid benchmark to assure us that a changes is from the active intervention alone.
• use of personal testimonials (anecdotes) as "proof" of the benefit of a product.
• misuse of statistical analysis to validate positive results.

The result? A product promoted as providing a helpful or beneficial effect when none is present - a placebo effect.

The Placebo (def: an inert compound, identical in appearance with the material being tested in experimental research, where the subject and the experimenter may or may not know which is which) effect is almost always positive as our optimism and hope that a medication, supplement, or training program will be beneficial, biases us toward a positive impression of the results. This explains why athletes, using a product without bothering with an inert comparison, almost always report the results in a positive way.

And the placebo effect can be significant. This study on the effect of caffeine on cycling performance is a great example.

The study group consisted of six male cyclists each of whom undertook two time trials to establish their baseline. Then the time trials were repeated 3 times with the cyclist being given one of three pills in a random order - either "placebo", "4.5 mg/kg caffeine", or "9.0 mg/kg caffeine". What they did not know was that all of the pills were placebos (none contained any caffeine). As caffeine does enhance performance, these experienced racers knew expected it would help them ride faster.

The results?

• 1.4 percent less power than baseline when they believed they had ingested a placebo,
• 1.3 percent more power when they believed they had ingested 4.5 mg/kg caffeine, and
• 3.1 percent more power when they believed they had ingested 9.0 mg/kg caffeine.

How can you sort out the placebo effect of any intervention? By comparing two groups of athletes of similar ability under carefully monitored or "controlled" circumstances. One group uses the active ingredient being investigated while the other group is given an inactive or sham agent the placebo. And both groups are "blinded" as to which agent they are using.

Using statistics appropriately is a common error. Chance alone will occasionally result in a positive finding in a well controlled study even when they was no real physiologic benefit to the agent being studied. Good clinical studies use statistical methods to minimize the potential of those rare random positive results being interpreted as indicating a reproducible effect.

But even well done, statistically valid studies may on rare occasions support a random positive but non-reproducible results. So if you find several studies, with only one supporting a positive or beneficial effect, be skeptical that the single positive result may have been by chance alone (and thus not reproducible). Be wary of the single, often quoted study with results no one else seems to be able to duplicate.

Here is a great example of the type of placebo affect I am referring to. Tropical Edge Lotion at $35 per bottle.

It really makes little sense to me. The skin is almost completely impervious to significant amounts of topical chemicals. Skin patches work for drug delivery, but only in microgram amounts. And when you are exercising, the amount of bicarbonate adsorbed is probably just a drop in the bucket of what is needed to produce a significant metabolic effect. Look at the active ingredients and only menthol is listed. Enough, I'm sure to make your legs feel like something is happening.

The "...rate of perceived exertion was 2.6% lower measured 15 minutes into a 1 hour time trial " is well within what you can see with a placebo effect. I tried to find a published reference and found (per website) that "The results of this study will be submitted for publication and additional studies are currently underway." As this phrase is often used as an excuse to avoid the peer review required before publication I'd give this a two thumbs down as far as a an effect of the bicarbonate in the lotion.

This article is an easy read reviewing the placebo effect and then focusing on the questionable ethics of selling products based on results from the placebo effect.

Once you find a product you feel has proven itself, you will have to decide how to use it to improve your personal cycling performance. Two questions to consider are:

• Dosing. It has been known for centuries that a large enough dose of a useful medication or chemical agent can be harmful or even fatal. The renaissance apothecary Paracelsus warned his contemporaries that "The poison is in the dose" and there is a fatal or harmful dose of almost any active chemical compound. An example is water. If you don't drink enough, you get dehydrated and will do poorly on a ride - so there is some amount that will be helpful to improving your performance. But if you overdo and drink excessively, you can develop hyponatremia, become ill, and at the extreme face the possibility of severe complications and even death. So the old adage that "if a little is good, a lot is better" does not hold true when using additives and supplements, and there is always a small amount of personal risk in pushing doses higher than those recommended from scientific studies.

• Appropriateness. Try to put claims (proven of course) in perspective. An improvement of a few percent obtained in repetitive sprints to exhaustion on a bike trainer may have little relevance for an endurance event or for the recreational cyclist.

Here is a story from an associate in a web coaching e-mail group, Graham Fowler, that helps to illustrate the point.

"During a lull in cycling I was involved in marathon canoeing as an instructor and competitor. It was during a 24 hour "orienteering" marathon that at approx 3 AM one of our mixed team of 5 became so sleepy and lethargic he insisted that he could not carry on. I had some salt tablets with me to stave off cramps etc. While resting on the water I told some story about these tablets being so strong that you wouldn't sleep for days if you took one. I broke one in half and in to quarters and gave him one, with a drink of water. I suggested that within 15 minutes he would be wide awake and completely rejuvenated. To my amazement his strength returned on cue and paddled as if he had just started. This man is now the president of the Skeptics Society of South Australia. I have never told him that they were salt tablets.

"Powerful stuff is belief".. The link explores how to tap into the psyche and use what many would call a placebo effect to improve your performance.

So what is the bottom line? Even if it is a placebo effect that explains advertised benefits, placebos almost certainly do no harm and the the purchaser may very well feel they are not wasting their money. But if you are on a tight budget or are looking for proven value for the dollars you spend, then it always pays to be a bit skeptical.