SUGAR - THE ANTITHETIC PERFORMANCE ENHANCER

BY DR BAYNE FRENCH

Sugar Refresher

Many substances are referred to as “sugar”. In my fighting days, they called me Sugar French. Later, I realised it was probably because people enjoyed fighting me, but that is beside the point.

From a biochemical standpoint, true sugar is sucrose. Sucrose consists of one molecule of glucose bound to one molecule of fructose. After sugar is consumed — ideally not very often — the enzyme sucrase splits it into these two components, which are then absorbed into the bloodstream.

Fructose occurs naturally in fruit, agave, honey and some vegetables. In whole, unprocessed foods, fructose is present in relatively small amounts. The fibre and phytonutrients in these foods also slow its absorption into the bloodstream, which is metabolically favourable.

High-fructose corn syrup (HFCS), however, is not naturally occurring. From a metabolic perspective, it is highly unfavourable. It contains more than 50% fructose and can be as high as 65%. HFCS was developed in 1957 at Oklahoma State University and entered the food supply in the 1970s. In 1984, both Coca-Cola and Pepsi switched from sucrose to HFCS. In my practice, I see endurance athletes who regularly consume these drinks. Many present with abdominal weight gain, acne, bloating, fatty liver and prediabetes.

HFCS is so biologically active and so disruptive to metabolism that signs of fatty liver disease in regular soft drink consumers are almost predictable — including in endurance athletes.

The glucose portion of sugar raises blood glucose levels, triggering an insulin spike and promoting fat storage. Over time, repeated insulin elevation can lead to insulin resistance and eventually Type 2 diabetes.

So sucrose has two metabolic weapons: glucose and fructose. Much like me in my fighting days, your best option is to run away and play dead.

Let Me Impress You With Other Big Words

1) Nitric Oxide

If I were a high-level endurance athlete — which I am — I would want abundant nitric oxide (NO) in my body. Nitric oxide performs many beneficial functions and is produced in a number of tissues, including the heart, liver and the inner lining of blood vessels.

As with most aspects of human physiology, the biochemistry of nitric oxide is highly complex. What is well established is that it increases blood flow to tissues by causing vasodilation. It also helps facilitate the entry of glucose into muscle cells.

If I were about to run far and fast, or carry a 700-pound elk out of the mountains one piece at a time, I would certainly want more blood reaching my muscles and more glucose entering those muscle cells. You probably would too.

And you can see where this is going: sugar interferes with the formation of nitric oxide. As I wrote in my recent article on uric acid:
“Why in the hell would you want to consume sugar with any regularity — or ever fuel with it?”

2) Antidiuretic Hormone (ADH)

Many ultra-elite, Olympic-calibre, exceptionally strong athletes — savage monsters like me — understand that performance depends heavily on the kidneys. Those two organs in your flanks regulate fluid and electrolyte balance. Like your muscles and mind, they are trainable.

Sugar, primarily through its fructose component, promotes the formation of antidiuretic hormone (ADH). ADH is a fascinating hormone, produced in the brain and then stored and released by the pituitary gland.

ADH matters to athletes because, as its name suggests, it reduces diuresis — in other words, it causes the body to retain water rather than excrete it. This is useful in the context of dehydration. ADH levels are typically elevated during intense exertion and, let’s be honest, nobody wants to stop and urinate during a race. That was one of the things I appreciated about obstacle course racing: when you are already soaked and covered in mud, certain inconveniences become less inconvenient.

The problem is that excess ADH impairs performance by causing too much fluid retention, which negatively affects your power-to-weight ratio. The more unnecessary weight you carry, the more your power declines. Unfortunately for athletic performance, ADH also causes vasoconstriction. In contrast, nitric oxide is a vasodilator that improves blood flow to muscle. ADH reduces that blood flow.

So again, you know where this is going: sugar promotes the formation of ADH. That means more fluid retention and less blood flow to your muscles. Companies that market sugar as an outstanding endurance fuel are either being deceptive or they do not understand the physiology. Claiming expertise while remaining ignorant is simply foolish.

3) ATP: Your Real Energy Currency

People often say, “I want to lose weight.” Not exactly. What they usually mean is, “I want to burn fat.” That is more precise.

People also say, “I want to run, cycle or swim faster.” More accurately, what they want is for their muscles to contract more efficiently, for longer, and with less fatigue. This is not just semantics — it is biology.

Enter adenosine triphosphate (ATP). ATP is the body’s fundamental energy currency. The chemical energy stored in ATP is converted into mechanical energy during muscle contraction. The production and use of ATP are central to optimal athletic performance. ATP is generated by the mitochondria inside our cells.

And yes, you know where this is going. Here is an excerpt from my recent article on uric acid:

“When we consume sugar, the enzyme fructokinase metabolises the fructose piece. This process uses ATP. Douard et al. (Journal of Physiology, January 2013) showed that a cellular fructose load, as provided by sugar-sweetened beverages, causes ATP to decrease by 40–50%. Sugar impairs performance by depleting our primary energy currency. The notion that sugar is a good fuel source for endurance pursuits is deeply physiologically and biochemically flawed and, in essence, science shows the opposite is true.”

Summary

The mechanisms outlined above are fundamental biochemical reasons why sugar works against optimal athletic performance. In truth, it also works against everyday, non-athletic performance.

Sugar, as a cornerstone of modern business and food marketing, needs to fade away, and the companies and philosophies built around promoting it should disappear with it. It really is that simple.

For lasting and meaningful change to happen, it must happen at the individual level. That means you must choose to do things differently. Educate yourself. Align with what makes sense to you. Surround yourself with people who operate authentically.