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CYCLING PERFORMANCE TIPS

  Last updated: 3/2020

ENERGY BARS, ENERGY GELS, ENERGY DRINKS (not sport drinks)

- are additives helpful?



Every week, it seems there is another energy drink, powder, or bar formulated to improve athletic performance. Just buy this one, the ads tout, and you'll increase your performance overnight. And, as you might expect, this "enhanced" product comes with a price tag that increases with each new variation. To sort things out, let's look at available facts on these products and the additives they contain - and then you can make up your own mind.

First, let's review the basic physiology of providing energy to your muscles. The Calories (energy) in food are released in a process called oxidation. Burning oil (a fat) in a lamp or a flaming sugar cube (a carbohydrate) as a decoration in a dessert are examples of oxidation. The Caloric energy is released as heat and light. In the body food energy is released more slowly in a process that harnesses this energy (via ATP) to support basic cell functions or the shortening of actin-myosin fibers in muscle cells.

All foods are composed of three basic compounds - carbohydrates, fats, and protein. Carbohydrates are the preferred energy source for the average cyclist and is essential for short, maximum performance events. Fats are also available as an energy source (via ATP) assuming more importance in endurance events (< 50% VO2 max). Proteins are only rarely used as an energy source and are instead used in building and repairing body tissues.

The energy content of carbohydrates, fats, and protein is measured in Calories (note the capital C). Carbohydrates and proteins contain 4.1 Calories per gram (120 Calories per ounce) while fat contains significantly more Calories per gram at 9 Calories per gram. Although fat would seem to be the optimal source of energy for physical activity, that is true only for endurance levels of exertion, that is ~ 50% VO2 max. Thus it is not useful for sprint level aerobic activities.

Many studies have confirmed the inability of fats (compared to carbohydrates) to sustain high level (high VO2 max.) aerobic, and anaerobic, performance.

What about a high fat diet for the several weeks? Maybe it would improve fat metabolism and thus change the results in competitive (high VO2max) aerobic performance compared to a diet high in carbohydrates and thus relatively restricted in fat Calories. Various arguments had been put forward, such as:

There are no studies supporting this theory - that a high fat diet for 2 weeks improved high VO2 max performance (cycling time to exhaustion at 90% VO2 max) over that of a group on a balanced diet minimizing fat, or a third group on a low fat diet (12% of Calories). Instead it is likely that any anecdotal performance improvement is from a placebo effect - such as a sense of well being associated with eating foods containing a higher percentage of fat.

But there have been two well controlled studies showing high fat diets (70% fat in one, 38% in the other) for 2 weeks before an increasing the time of exercise to exhaustion for endurance level activities at 50% VO2 max (80 vs 42 minutes of cycling in one, 76 vs 70 minutes of running in the other). Glycogen sparing effects were studied to determine if it might have been from a preferential shift to fat metabolism during exercise after a high fat diet, but none were found.

Another study tracked Calorie replacement after exercise in two groups (a low fat diet vs normal/high fat foods) and found that those on a low fat diet did NOT replace all the Calories expended during a training program while the group on a more liberal fat diet did. This suggested another reason for poor performance on a low fat diet - the development of a long term Caloric deficit during training which lead to more limited muscle glycogen stores going into the next ride. But it isn't just about Calories replaced. Good glycogen stores are important and a chronic deficit replacing carbohydrates used in exercise has been linked to chronic fatigue..

In addition to the questionable exercise performance benefits, it has been proven beyond doubt that a long term, high fat diet leads to heart disease. And for those who still aren't convinced, remember that even the leanest athlete has plenty of stored fat available (approximately 100,000 Calories worth in a 70 kg male) on a balanced diet.


FACT NUMBER ONE - BASED ON NUMEROUS STUDIES, GLUCOSE OR CARBOHYDRATES ARE THE PREFERRED TO FAT AS AN ENERGY SOURCE FOR AEROBIC (GREATER THAN 50% VO2 MAX) AND ANAEROBIC EVENTS.

Let's look at the basic energy bar and energy gel.

Commercial power-bars are generally carbohydrates (of varying types) as well as containing special supplements such as those I'll mention below. Their main advantage is being prepackaged, readily available commercially, and offering another taste and texture option for an on the bike snack. But as a carbohydrate, they are no more effective on a gram for gram basis than other other carbohydrates.

A study from Ball State University demonstrated that a pre event meal of old fashioned oatmeal gave the same boost to endurance performance as a commercial energy bars. Or, it has to be assumed, over other commercially available carbohydrate snacks such as fig newtons.

Energy gels (as well as drinks - including powders for your water bottle) are an alternative to the often hard to unwrap, difficult to chew, and frequently tasteless commercial energy bars. These products are a combination of simple and complex carbohydrates packaged in a palm sized packet of plastic or foil with a tear off end which allows the contents to be "sucked" out rather than chewed. They contain between 70 and 100 Calories per packet (17 - 25 grams of carbohydrate) and have the advantage of being completely fat free. They also empty more quickly from the stomach and their only advantage may be that as a liquid or semi-liquid they provide a more rapid absorption and energy boost than solid energy bars.


FACT TWO - THERE IS NO EVIDENCE THAT THE CARBOHYDRATE IN ENERGY BARS OR ENERGY GELS IS MORE EFFECTIVE TO SUPPLY MUSCLE ENERGY THAN, FOR EXAMPLE, THE CARBOHYDRATE IN TRADITIONAL OVER THE COUNTER SNACKS SUCH AS FIG NEWTONS.


FACT THREE - ASIDE FROM CAFFEINE, WHICH MAY PROVIDE PERFORMANCE ENHANCEMENT IF USED CORRECTLY AND IN LIMITED AMOUNTS, THERE IS NO EVIDENCE THAT OTHER ELECTROLYTE OR MINERAL ELEMENTS PROVIDE A PERFORMANCE EDGE.


FACT FOUR - THERE IS NO EVIDENCE OF PERFORMANCE ENHANCEMENT FROM FORCING DIETARY FAT BEFORE, OR IN A SUPPLEMENT DURING A COMPETITIVE EVENT.

The fat content of some energy bars which is alleged to:

While there has been controversy as to the benefits of "slow training", long slow rides, or a high fat training diet, in improving the body's ability to metabolize and use stored fat Calories for muscle energy, there is no basis for the claims made by these supplements that fat will enhance performance. The biggest benefit is to improve the taste of these bars/gels.

If you are a believer in being able "training" your body's metabolism to use fat as an energy source, an alternative to fat supplements in bars would be to focus on a training program of a high mileage at a relatively slow pace (60% VO2 max.) to force metabolism of your own fat stores (of over 100,000 Calories). You could, in addition, avoid carbohydrates while training, minimizing carbohydrate supplements while on that long slow ride, to further force the development of these alternative metabolic pathways for fat (essentially a planned "bonk"). Then, or so goes the theory, when it comes time for that sprint at the end of a competitive event (ridden with appropriate glucose supplementation), having used more fat than glycogen, you would have more glycogen available for that anaerobic sprint at the end. The only problem is that there is very little evidence this happens. And what you get little in return is the chance to train in a chronically glycogen depleted state - feeling as if you are chronically bonked.

Medium chain triglycerides are a form of fat more easily absorbed from the intestinal tract, but metabolized by the muscle cells exactly like any other fats, and are probably of no more benefit than adding an extra pat of butter on your pancakes before the ride. And at a few grams per bar, they provide minimal additional Calories to the carbohydrate content.

FACT FIVE - PROTEIN IS NOT SUPERIOR TO ADEQUATE CARBOHYDRATES WHILE RIDING.

Finally, it has been suggested that a combination of protein (amino acids) and carbohydrates in a ratio of 1:4 is more effective in sports drinks/gels/bars eaten while riding and in supplements for glycogen repletion immediately after a ride. There is no information in the literature supporting a benefit from protein enhanced carbohydrate supplements while riding.

There is data for a benefit of protein increasing glycogen repletion in the post ride recovery period. But simply increasing the amount of carbohydrate Calories to 1 gram/kg/hr x 3 - 4 hours appears to maximize repletion rates.


FACT SIX - ENERGY DRINKS ARE NOT RISK FREE

This is just a single case report, but it makes the point that any supplement should be taken only after asking yourself

  1. is there evidence it works?
  2. and if the science says it does, are the possible risks, even small, worth it?
The many adverse event reports received by the US Food and Drug Administration include psychiatric symptoms, arrhythmias, cardiac arrest, myocardial infarction, convulsions, and renal and liver impairment. And multiple cases of energy drink-induced acute kidney injury or acute hepatitis are reported in the literature.

The mechanisms of injury are not well studied but the ingredients of energy drinks are many including caffeine, L-carnitine, taurine, B vitamins, glucuronolactone, antioxidants, trace minerals, guarana, sucrose, Ginkgo biloba, and/or ginseng.

Until more research reveals safe amounts of energy drinks and their ingredients, excessive use should be avoided. Just because you can buy a product over the counter at the 7-11 or in a health food store does not mean it is risk free ...or healthy.


RED BULL, MONSTER, AND OTHER "ENERGY DRINKS"

Energy bars (the original Clif Bars for example) and gels started off as a convenient source of carbohydrate energy for aerobic muscle metabolism while on the bike. Then the black magic of "additives" was applied and we ended up with energy drinks such as Red Bull and Monster.

Do these energy drinks improve performance? Not when compared to an carbohydrate equivalent (equi-caloric) caffeine/glucose drink.

Are you risking more than your wallet? Are they potentially harmful? As we've seen above, yes.

They not only lead to an immediate increase in blood pressure, but also have been linked to cardiac arrhythmia and sudden death. This interview from Medscape.com provides additional insight into the reasons for their negative cardiovascular effects.

Finally, we know they can increase inflammatory blood markers such as C-reactive protein. This chronic inflammation will injure normal tissues, and when monitored over time, groups with elevated C-reactive protein levels have been shown to have higher rates of diabetes, cardiovascular disease, and cancer.


So what is the bottom line on additives in energy bars and gels?

So I'm sticking with coke, or Oreo cookies, for my on-the- bike carbohydrate supplements, and keeping a traditional energy bar in my fanny pack for the time I forget and really need that energy boost.


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Cycling Performance Tips
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