Fuel for Sport

Energy is the currency of performance. Athletes rich in energy have a better chance at performance success than those poor in energy and laden with fatigue. Depending on the demands and operating conditions, the body produces energy in several different ways, each which can be impacted by natural ingredients.

Energy is released when the bonds of adenosine triphosphate (ATP) are broken inside body cells. After these bonds break, adenosine diphosphate (ADP) is left and must add new phosphate to restore to ATP. This is the basis for all energy dynamics inside the body. The differences lie in how the body accesses and restores ATP.

Creatine phosphate, also known as phosphocreatine, can quickly donate phosphate to ADP to make ATP. The restoration of ATP using phosphocreatine is performed in anaerobic conditions. Supplemental creatine has become a popular way for athletes to increase muscle levels of creatine phosphate in hopes of providing an extra boost to the quick ATP production used for short, intense bursts of exercise.

Creatine monohydrate has long been the choice for most users, but alternate forms have emerged and claim to address longstanding issues with creatine. For instance, buffered creatine—Kre-Alkalyn®, from All American Pharmaceutical, a prime example—is billed as a safer, more stable form of creatine, as it limits the breakdown of creatine to creatinine before it enters the muscle. The buffered creatine is thought to offer not just increased safety, but also bioavailability.

Alternative forms have come from bonding creatine to other nutrients. Albion developed a creatine-magnesium chelate for improved absorption and bioavailability. Its Creatine MagnaPower® combines the ATP regeneration of creatine with the electrolyte and muscle nutrition of magnesium—this mineral also plays a role in energy production by supporting certain enzymes used to make ATP in both aerobic and anaerobic conditions.

Thermolife International bonded creatine to nitrate, a popular vasodilating compound for improved blood flow — nitrates increase levels of nitric oxide (NO), which relaxes smooth muscle cells such as found in blood vessel walls. The benefit of this combination, according to the company, is improved absorption and lower dosing requirements.

Several natural ingredients, especially root-based compounds, provide nitrates, but many blood flow supplements focus on arginine, which is converted in the body into NO. Nutrition 21 developed a proprietary inositol-stabilized arginine silicate (Nitrosigine®) for improved blood flow in support of both performance and energy increases (J Int Soc Sports Nutr. 2015; 12(Suppl 1): P14).

Increased blood flow delivers more oxygen to the muscles. While creatine phosphate and stored ATP can supply short bursts of anaerobic activity, such as in sprinting or weightlifting, other types of exercise and sports require more sustained energy production and availability.

The first preferred method of ATP production is via glycolysis, a process that converts blood glucose or muscle glycogen into ATP and assorted byproducts. Carbohydrates are the quickest source of glucose for glycolysis. The body either uses carbs to make ATP or stores them as glycogen.

The primary dietary carbs for increased glucose are sucrose, or common table sugar, and maltodextrin, which is often found in sports nutrition products—complex carbs, such as maltodextrin, are better at increasing muscle glycogen than are simple carbs such as glucose, dextrose and fructose.

However, dextrins and glucose have a low molecular weight, which can increase osmotic pressure when used in sports drinks, and ultimately trigger nausea and digestive distress from increased gastric emptying time. Glico Nutrition developed Cluster Dextrin®, a highly branched cyclic dextrin (HBCD) with a higher molecular weight and no negative impact on gastric emptying time.

Ribose is a five-carbon carbohydrate either made in the body from glucose or ingested via the diet. It is part of the structural backbone of the ATP molecule, which is why Bioenergy developed Bioenergy Ribose® to help the body reproduce ATP more quickly than with sucrose, maltodextrin or other common carbs.

Early or “fast” glycolysis occurs in anaerobic conditions, using enzymatic reactions to produce a small amount of ATP as well as pyruvate and hydrogen ions.

In the absence of oxygen, hydrogen ions and lactate can flood the muscles, changing the pH balance and creating a state of acidosis and subsequent fatigue. Supplementing with the amino acid beta alanine can increase levels of carnosine, a dipeptide that helps buffer hydrogen ions, removing them from muscles and limiting fatigue.

As oxygen from increased breathing begins to hit the muscle cells, aerobic or “slow” glycolysis takes over. This process is marked by oxidative reactions used to produce larger amounts of ATP. In the presence of oxygen, the pyruvate from early glycolysis oxidizes into coenzyme A (CoA) inside the cell mitochondria and combine with oxaloacetate to form citric acid; this drives a series of reduction and oxidation reactions to produce ATP via the tricarboxylic acid (TCA) or Krebs cycle.

Like the action of beta alanine and carnosine, the amino acids L-alanine and L-glutamine (as Sustamine®, from Kyowa Hakko) can stave off fatigue by removing muscle ammonia leftover from amino acid metabolism. Glutamine can also be converted enzymatically into α-ketoglutarate, which helps drive ATP production from a different position in the Krebs cycle than does CoA.

While carbs are the primary source of glucose and eventually CoA for the Krebs cycle, fats stored as triglycerides can also be converted into CoA. For this, fatty acids must be transported into the mitochondria by carnitine. About 95 percent of the body’s carnitine stores are found in skeletal muscle, but carnitine is also ingested from meat and dairy in the diet. Lonza developed carnitine tartrate (as Carnipure®) to help increase muscle carnitine levels and boost ATP production from fatty acids; this also spares muscle glycogen during exercise.

Choline is another transporter of fats for energy production and is commonly found in the body in phospholipid form as phosphatidylcholine (PC).

Fat as fuel is a hallmark of ketogenic dieting. During fasting or a very low carbohydrate diet, the body runs out of carbs/glucose and turns to fat oxidation for energy.  The body uses acetyl coenzyme A to make ketones, such as acetoacetate and beta-hydroxybutyrate (BHB), which can feed the Krebs cycle and then the electron transport chain.  

While the liver makes ketones from fats, Compound Solutions developed a BHB ingredient, goBHB™, to help consumers deliver more ketones to their cellular energy system and improve not just sports performance, but also weight management and general energy needs. The company also pairs goBHB with its medium-chain triglyceride (MCT) ingredient, goMCT™, which can serve as a readily available source of ketone-making material.