Chemistry and sport

General Health and Physique
Sugar - the toxic truth
A recent comment in the magazine Nature (2 February 2012, Vol 482, pps 27-29) by Lustig and colleagues, highlights the changing concern of sugar in food. The comments that follow are instructive as well!

Improvement in records - due to equipment or health?
According to a report by Nick Linthorne:
In many athletic events, very little of the overall improvement in the past 100 years has been due to innovation in the design of sports equipment or the materials used. The main causes of improvement are socio-economic factors such as increased leisure time, increased professionalism of sport, state-supported sports systems, and the increased participation rate of women. Some of the improvement in performance may be due to better coaching and training methods, particularly in strength training and cardiovascular training, and advances in sports medicine that have prolonged athletic careers. In most cases there were temporary declines in performance due to World War I and World War II. In some events, particularly for women, there was a noticeable decline in performance starting in 1989. This was due to the demise of the organised sports systems in the Eastern European nations and the more expansive drug testing programs that were introduced following the disqualification of Ben Johnson at the 1988 Olympic Games.
Human height
Height can play a significant role in contributing to success in some sports by offering certain natural advantages. For those sports where this could be a contributing factor, height can be useful (although certainly not in all cases, and is not the only factor) since in general it affects the leverage between muscle volume and bones towards greater speed of movement and power, depending on overall build, fitness and individual ability. However, there can also be significant disadvantages posed by size and resultant mass that could prove to be a hindrance to success. Finally, there are numerous sports where size may be irrelevant.

Taller players have an advantage in basketball because their shots have less distance to travel to the basket; they start out closer to the rebound; and their ability to reach higher into the air yields a better chance of blocking shorter players' shots.

In college and professional basketball, even the shortest players are usually above the average in height compared to the general population. In men's professional basketball, the guards, the smallest players, are usually around 1.83 m (6 ft 0 in) to 1.91 m (6 ft 3 in), the average height for basketball players is about 2.01 m (6 ft 7 in) and the centers, the tallest players, are generally from 2.08 m (6 ft 10 in) to 2.18 m (7 ft 2 in).

In cricket, some of the great batsmen like Donald Bradman 1.70 m (5 ft 7 in), Sachin Tendulkar 1.65 m (5 ft 5 in) and Sunil Gavaskar 1.63 m (5 ft 4 in) are or were below average height. This may be because a smaller body makes for an advantage in footwork and balance. Similarly, the most graceful wicket-keepers have tended to be average height or below. Although there are fewer tall batsmen, the stand-outs are often noted for their heavy hitting and an ability to get a long stride forward to reach a full length delivery. Chris Gayle at 1.91 m (6 ft 3 in) is a modern example of a powerful, tall batsman. Past greats like Clive Lloyd and Graeme Pollock were above 1.80 m (5 ft 11 in).

On the other hand, many of the most successful fast bowlers have been well above average height; for example past greats Joel Garner, Courtney Walsh, and Curtly Ambrose were all approximately 2.00 m (6 ft 6 1/2 in) tall. Similarly, Glenn McGrath, regarded as one of the finest bowlers to play the game, was 1.95 m (6 ft 5 in) tall, well above average height. Taller bowlers have access to a higher point of release, making it easier for them to make the ball bounce uncomfortably for a batsman. For extreme pace however, bowlers tend to be closer to average height. The fastest modern bowlers have ranged from Lasith Malinga 1.68 m (5 ft 6 in) through to Dilhara Fernando at 1.90 m (6 ft 3 in), and Steve Harmison and Shaun Tait at 1.93 m (6 ft 4 in). Current Australian left-arm fast bowler Mitchell Johnson is 1.89 m (6 ft 2 in).

Height does not appear to be an advantage to spin bowling and few international spinners are ever much taller than 1.80 m (5 ft 11 in). Tall spin bowlers like Sulieman Benn, 2.01 m (6 ft 7 in) use extra pace and bounce, whereas spin is traditionally about using a looping, plunging trajectory at slow (70-90 km/h or 40-60 mph) speeds. The most successful bowlers ever in Test cricket, Muttiah Muralitharan and Shane Warne are 1.70 m (5 ft 7 in) and 1.83 m (6 ft 0 in) respectively.

Height is generally considered advantageous in swimming. Taller swimmers with longer arms are able to achieve better leverage, hence more acceleration, in the water. And water resistance goes down with increasing height.

This is especially true for freestyle. An example of a tall swimmer is Michael Phelps, at 1.93 m (6 ft 4 in) who won eight gold medals at the 2008 Olympic Games and clocked up another set at the 2012 Olympic Ganes in London. Ian Thorpe is 1.95 m (6 ft 5 in). The average height of the eight finalists in the 100 meter Freestyle final at the 2008 US Olympic Trials was 1.96 m (6 ft 5 in).

Jamaican statistics
A survey conducted in Spanish Town during 1994-1996 of 520 men and 776 women aged between 25 and 74 found that the average height for men was 1.72 m (5 ft 7 1/2 in) and for women was 1.61 m (5 ft 3 1/2 in). Waist size was found to be positively correlated with blood pressure and fasting blood glucose with men's waists measured at 80.9 cm and for women 83.4 cm. There was a 10-fold elevated risk for diabetes type 2 for men between the lowest and highest quartiles of waist circumference.

All physical and mental activity requires a source of energy and this is normally provided by the digestion and processing of our food into chemical energy. Metabolic processes that use adenosine triphosphate (ATP) as an energy source convert it back into its precursors. ATP is therefore continuously recycled in organisms: the human body, which on average contains only 250 g of ATP, turns over its own body weight in ATP each day, i.e is recycled about every five minutes!
ATP + H2O ↔ ADP + Pi   ΔG° = -30.5 kJ/mol
ATP + H2O ↔ AMP + PPi   ΔG° = -45.6 kJ/mol
Here ADP and AMP are adenosine diphosphate and adenosine monophosphate. The amount of ATP stored in muscle is limited, typically lasting only the first few seconds in a sprint, so the body must continually replenish its store of ATP. Three energy systems are available for this.
Primary Energy Sources
Intensity Zone Event Duration Level of Intensity Primary Energy System %Bioenergetic Contributions
        Anaerobic Aerobic
1 < 6 s Maximum ATP-PC 100-95 0-5
2 6-30 s High ATP-PC and Fast Glycolysis 95-80 5-20
3 30 s - 2 min Moderately High Fast and Slow Glycolysis 80-50 20-50
4 2-3 min Moderate Slow Glycolysis and Oxidative 50-40 50-60
5 3-30 min Moderately Low Oxidative 40-5 60-95
6 > 30 min Low Oxidative 5-2 95-98

Phosphagen (ATP-PC) System
Exercise that lasts for less than six seconds and is of high intensity utilises this system. The phosphagen system contains three basic reactions that are used in the production of ATP. The first of these is the reverse of the first reaction shown above. The other reactions needed to maintain ATP availability and replenish the ATP stores in skeletal muscle include the following:
        Enzyme: Creatine Kinase

     ADP + CP ↔ ATP + Creatine
In the reaction above the ATP is resynthesised from ADP and creatine phosphate (CP), also called phosphocreatine (PCr), such that phosphate is released from CP and combined with ADP to make ATP.
A third reaction involves conversion of 2 molecules of ADP into AMP and ATP. The P released from 1 ADP can recombine with another ADP, resulting in the reformation of ATP.
    2ADP ↔ ATP + AMP
Glycolytic System (Glycolysis)
Glycolysis is the breakdown of carbohydrates, either glycogen stored in the muscles or glucose delivered via the blood, to pyruvate. The pyruvate thus formed may react via two pathways depending on the intensity and duration of exercise.
Fast Glycolysis
ATP resynthesis occurs at a faster rate, but is limited in duration. Fast glycolysis can be summarized as follows:
    Glucose + 2P +2ADP ↔ 2 Lactate + 2ATP + H2O
When glycolysis occurs at a very rapid rate there is the possibility that lactate and H+ can accumulate and this has been linked to fatigue and ultimately a cessation of activity.

Slow Glycolysis and the Oxidative Phosphorylation system
In most conditions, anaerobic metabolism occurs simultaneously with aerobic metabolism because the less efficient anaerobic metabolism must supplement the aerobic system due to energy demands that exceed the aerobic system's capacity. What is generally called aerobic exercise might be better termed "solely aerobic", because it is designed to be low-intensity enough not to generate lactate via pyruvate fermentation, so that all carbohydrate is aerobically turned into energy.

Initially during increased exertion, muscle glycogen is broken down to produce glucose, which undergoes glycolysis producing pyruvate which then reacts with oxygen via the tricarboxylic acid (TCA) cycle [otherwise called the Krebs or citric acid cycle], to produce carbon dioxide and water and releasing energy. If there is a shortage of oxygen (anaerobic exercise, explosive movements), carbohydrate is consumed more rapidly because the pyruvate ferments into lactate.
Glucose + 2P + 2ADP + 2NAD+ ↔ 2Pyruvate + 2ATP + 2NADH + 2H2O
glucose + 6 O2 + 38 ADP + 38 phosphate ↔ 6 CO2 + 6 H2O + 38 ATP
Carbon dioxide, water and ATP are the final products.
As carbohydrates deplete, fat metabolism is increased so that it can fuel the aerobic pathways. The latter is a slow process, and is accompanied by a decline in performance level. This gradual switch to fat as fuel is a major cause of what marathon runners call "hitting the wall". Anaerobic exercise, in contrast, refers to the initial phase of exercise, or to any short burst of intense exertion, in which the glycogen or sugar is respired without oxygen, and is a far less efficient process. Operating anaerobically, an untrained 400 meter sprinter may "hit the wall" short of the full distance.

The aerobic system will begin to utilise fatty acids (fat) once the glycogen stores are exhausted, after approximately 25 minutes of continuous activity. A heavy training session can deplete carbohydrate stores in the muscles and liver, as can a restriction in dietary intake. Carbohydrate can release energy much more quickly than fat so are used for short sharp bursts of activity.

Note that based on the energy release figures it means that if the human body relied solely on carbohydrates to store energy, then a person would need to carry 31 kg (67.5 lb) of hydrated glycogen to have the energy equivalent of 5 kg (10 lb) of fat.

Implications of Blood Lactate levels
Lactate threshold variation with exercise
variation of the lactate threshold with training

Resting blood lactate concentrations are generally < 2 mmol/L, but as we exercise concentrations steadily increase. As we become more accustomed to interval training our muscles become more tolerant to lactate and we can work for longer periods.
Lactate threshold (LT) is the first workload at which there is a sustained increase in blood lactate concentration above resting levels. There is an approximately 1 mmol/L rise from resting levels.
Anaerobic threshold (AT) or sometimes referred to as onset of blood lactate accumulation (OBLA) is defined as the workload causing a rapid rise in blood lactate indicating the upper limit of production and clearance. Blood lactate concentrations at AT are approximately 4 mmol/L.

If an athletes lactate levels were tested in week 1, then again after training in week 12, we would expect the curve to have shifted to the right, indicating:
Among the recognized benefits of doing regular aerobic exercise are:
As a result, aerobic exercise can reduce the risk of death due to cardiovascular problems. In addition, high-impact aerobic activities (such as jogging or using a skipping rope) can stimulate bone growth, as well as reduce the risk of osteoporosis for both men and women.

In addition to the health benefits of aerobic exercise, there are numerous performance benefits:
Sports Drinks
Which drink is better when it comes to rehydrating during or after exercise? Should you choose water, coffee or tea perhaps? Maybe juice or carbonated drinks are best? And what is it about sports drinks that make them so effective? Chemists have determined the answer to all of these questions.

Sports drinks can be characterised as:
Most sports drinks are moderately isotonic, having 13 and 19 gram of sugar per 250 ml serving.
Examples of sports drinks include:
Coconut Water

Coconut water has being marketed as a natural sports drink because of its high potassium (> 220 mg/100 g) and mineral content. In addition it contains antioxidants linked to a variety of health benefits. Cytokinins such as kinetin in coconut water may be among its most beneficial components. Kinetin has been suggested as having a strong anti-ageing effect on human skin cells and skin care products containing kinetin have been developed to treat photo-damaged skin.

Unless the coconut has been damaged, it is likely sterile. There have been cases where coconut water has been used as an intravenous hydration fluid in some developing countries where medical saline was unavailable.

Note as well a study from the St Augustine campus of UWI, on coconut water/mauby for hypertension

Liz Applegate, director of sports nutrition at UC Davis commented on the use of coconut water after strenuous activity
Coconut water contains the electrolytes sodium, potassium, magnesium, calcium and phosphate as well as small amounts of many essential amino acids. That roster of minerals has made it popular among fitness junkies looking for a natural alternative to sports drinks without artificial colors or preservatives, Applegate said.

But though coconut water is fine for "the typical working-out person," she says, it's not for athletes engaged in intensive training, because compared with some commercial sports drinks, it is low in carbohydrates and sodium, which are essential for recovery following hard-core training.

Coconut water contains very little protein, which is crucial in a true recovery drink, says Becci Twombley, director of sports nutrition at UCLA. She says that after a hard workout, adults need at least 15 to 17 grams of protein; 8 ounces of coconut water contains less than 2 grams of protein, according to an analysis that Singaporean researchers published in 2009.

On the other hand, coconut water contains up to 15 times as much potassium as the average sports drink. Like sodium, potassium is a key electrolyte that gets sweated out during exercise. But because the body loses more sodium than potassium during a workout, all that extra potassium isn't necessarily important in a sports drink, Applegate says. (There's certainly no harm in it either, she adds.)

A few small studies by researchers in Malaysia suggest that coconut water can rehydrate the body about as reliably as a sports drink and perhaps a little better than plain water. In one study, eight men exercised in the heat until they lost about 3% of their body weight and then drank either coconut water, plain water or a sports drink to rehydrate. All three beverages replenished the men equally.

In a second study, 10 men who exercised in the heat for 90 minutes drank either water, a sports drink, coconut water or coconut water plus sodium. After two hours, those who drank the sports drink and coconut waters were slightly more rehydrated - measured by the amount of body weight they regained - than those who drank the pure water. That makes sense, says Twombley, since electrolytes in the sports drink and coconut water would facilitate the body's water uptake. The study was published in the Southeast Asian Journal of Tropical Medicine and Public Health.
Gatorade, Lucozade, OK, but what about chocolate milk?
Protein replenishment
It has been found that the resynthesis of glycogen between training sessions occurs most rapidly if carbohydrates (CHO) are consumed within 30 min to 1 h after exercise. Indeed, delaying carbohydrate ingestion for 2 h after a workout can reduce the rate of glycogen resynthesis by as much as half. In addition to replenishing the carbohydrates lost during intensive exercise and correcting any sodium imbalance, it has been found that addition of protein (at a carbohydrate-to-protein ratio of 2 to 2.9:1) can hasten the rate of glycogen synthesis and improve endurance recovery.
Ref: International Journal of Sport Nutrition and Exercise Metabolism, 2006, 16, 78-91.
In this study nine male, endurance-trained cyclists performed an interval workout followed by 4 h of recovery, and a subsequent endurance trial to exhaustion at 70% VO2max, on three separate days. Immediately following the first exercise bout and 2 h of recovery, subjects drank isovolumic amounts of chocolate milk, fluid replacement drink (FR), or carbohydrate replacement drink (CR), in a single-blind, randomized design. Carbohydrate content was equivalent for chocolate milk and CR. The time to exhaustion (TTE), average heart rate (HR), rating of perceived exertion (RPE), and total work (WT) for the endurance exercise were compared between trials. TTE and WT were significantly greater for chocolate milk and FR trials compared to the CR trials. The results of this study suggest that chocolate milk is an effective recovery aid between two exhausting exercise bouts.
Here FR was Gatorade, CR was Endurox R4 and the chocolate milk was a low-fat product from The Kroger Co.

Taurine in sports drinks.

taurine 3D structure

Taurine, or 2-aminoethanesulfonic acid, is a major constituent of bile and can be found in the large intestine and in the tissues of many animals, including humans. Taurine has a ubiquitous distribution and accounts for approximately 0.1% of total body weight.

The determination of taurine in sports drinks using HPLC was the subject of the J Chem Educ., 2001 (78), 191 laboratory exercise article.

Nutritional significance
Despite being present in many energy drinks and dietary supplements, and being a required nutrient for some animals, taurine has not been shown to beneficial in human nutrition. A study of mice hereditarily unable to transport taurine suggests that it is needed for proper maintenance and functioning of skeletal muscles. In addition, it has been shown to be effective in removing fatty liver deposits in rats, preventing liver disease, and reducing cirrhosis in tested animals. There is also evidence that taurine is beneficial for adult human blood pressure and possibly, the alleviation of other cardiovascular ailments (in humans suffering essential hypertension, taurine supplementation resulted in measurable decreases in blood pressure).

Taurine is regularly used as an ingredient in energy drinks, with many containing 1000 mg per serving, and some as much as 2000 mg. A 2003 study by the European Food Safety Authority found no adverse effects for up to 1,000 mg of taurine per kilogram of body weight per day.

A review published in 2008 found no documented reports of negative or positive health effects associated with the amount of taurine used in energy drinks, concluding that "The amounts of guarana, taurine, and ginseng found in popular energy drinks are far below the amounts expected to deliver either therapeutic benefits or adverse events".

In 1993, approximately 5,000 - 6,000 tons of taurine were produced for commercial purposes; 50% for pet food manufacture, 50% in pharmaceutical applications. As of 2010, China alone has more than 40 manufacturers of taurine. Most of these enterprises employ ethanolamine as starting material to produce a total annual production of about 3,000 tons.

Death by water.
Consumption of excessive amounts of water can cause water intoxication, a potentially fatal imbalance of electrolytes in the body. Water intoxication is fortunately extremely rare. It has occurred, for example, during intense exercise when heavy sweating removes water and electrolytes from the body, and large quantities of water were consumed to replace what had been lost. The resulting low concentration of electrolytes adversely affected the central nervous system function. This can lead to a condition called Hyponatraemia that may result in death.

Creatine - the Power Supplement
Creatine is a nitrogenous organic acid that occurs naturally in vertebrates and helps to supply energy to all cells in the body, primarily muscle. This is achieved by increasing the formation of Adenosine triphosphate (ATP).

Creatine supplements are sometimes used by athletes, bodybuilders, wrestlers, sprinters and others who wish to gain muscle mass, typically consuming 2 to 3 times the amount that could be obtained from a very-high-protein diet. A survey of long-term use gives the creatine content of several foods. The Mayo Clinic states that creatine has been associated with asthmatic symptoms and warns against consumption by persons with known allergies.

While there was once some concern that creatine supplementation could affect hydration status and heat tolerance and lead to muscle cramping and diarrhea, recent studies have shown these concerns to be unfounded.

There are reports of kidney damage with creatine use, such as interstitial nephritis; patients with kidney disease should avoid use of this supplement. In similar manner, liver function may be altered, and caution is advised in those with underlying liver disease although studies have shown little or no adverse impact on kidney or liver function from oral creatine supplementation.

Long-term administration of large quantities of creatine is reported to increase the production of formaldehyde, which has the potential to cause serious unwanted side-effects. However, this risk is largely theoretical because urinary excretion of formaldehyde, even under heavy creatine supplementation, does not exceed normal limits.

Extensive research over the last decade has shown that oral creatine supplementation at a rate of 5 to 20 grams per day appears to be very safe and largely devoid of adverse side-effects, while at the same time effectively improving the physiological response to resistance exercise, increasing the maximal force production of muscles in both men and women.

Creatine use is not considered doping and is not banned by the majority of sport-governing bodies. However, in the United States, the NCAA recently ruled that colleges could not provide creatine supplements to their players, though the players are still allowed to obtain and use creatine independently.

testosterone (with red double bond), dihydrotestosterone (without double bond)

Creatine increases the conversion rate from testosterone to dihydrotestosterone (DHT) in the body. In men, approximately 5% of testosterone usually undergoes 5α-reduction to form the more potent androgen, dihydrotestosterone. DHT has approximately three times greater affinity for androgen receptors than testosterone and has 15-30 times greater affinity than adrenal androgens. A 2009 study showed that after a 7 day loading phase of creatine supplementation, followed by a further 14 days of creatine maintenance supplementation, while testosterone levels in blood serum were unchanged, levels of dihydrotestosterone increased by 56% after the initial 7 days of creatine loading and remained 40% above baseline after 14 days maintenance. The ratio of dihydrotestosterone to testosterone also increased by 36% after 7 days creatine supplementation and remained elevated by 22% after the maintenance dose. This could explain the fact that creatine users tend to report a slight onset of acne after starting creatine supplementation. It could also be a factor when it comes to the increased athletic performance that has been correlated with creatine supplemenation.

Chromium(III) picolinate

Chromium(III) picolinate is marketed as a nutritional supplement to prevent or treat chromium deficiency. The bright-red coordination complex is derived from chromium(III) and picolinic acid. Small quantities of chromium are needed for glucose utilization by insulin in normal health, but deficiency is extremely rare and has only been observed in hospital patients on long-term defined diets.

Some commercial organizations promote chromium picolinate as an aid to body development for athletes and as a means of losing weight. Note however that a number of studies have failed to demonstrate an effect of chromium picolinate on either muscle growth or fat loss.

Design and Materials in Athletics. Nick Linthorne shows the changes technology has made in a number of athletic events and plots the average result for the 10th best athlete in the world for these events.

Much of the information in these course notes has been sourced from Wikipedia under the Creative Commons License. Students taking this course will be expected to contribute to Wikipedia as a part of their course assignments.
Continue to Equipment or return to CHEM2402 course outline.

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Created September 2011. Links checked and/or last modified 17th October 2014.