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Every sport has its own unique nutrition needs, including rowing. Carbohydrate, protein, and fat intake are all crucial to optimal performance. Athletes must be well-hydrated before exercise, and consume adequate liquid during and after performance to balance fluid loss. Appropriate selection of foods and fluids, the timing of intake, and supplement choices are important for optimal health and exercise performance (Ray & Fowler, 2004). Your diet ratio's have been set out using guidelines by Hagerman (2006) who stated that on average a rowers' diet should consist of 65% carbohydrates, 20% protein, and 15-20% fat.
An important goal of an athlete's everyday diet is to provide the muscle with substrates to fuel the training program that will achieve optimal adaptation and performance enhancements (Burke et al., 2004). The ability to perform prolonged aerobic exercise is determined predominantly by fuel availability (Moore et al., 2009).
Body fat and carbohydrate stores provide the major sources of fuel for exercise. Fat sources such as plasma free fatty acids derived from adipose tissue and intramuscular triglycerides are abundant within the body, carbohydrate sources such as plasma glucose derived from the liver or dietary carbohydrate intake, and muscle glycogen stores are very limited (Coyle 1995)
There have been many studies proving that carbohydrate consumption significantly enhances endurance performance (Ivy et al., 2002). According to Tzintzas et al., (1995) and Coyle et al., (1986) this is due to a reduction in muscle glycogen utilization and maintenance of blood glucose levels during exercise.
According to Ivy et al., (1998) The highest rates of muscle glycogen storage occur during the first hour post exercise, due to activation of glycogen synthase by glycogen depletion (Wojtaszewski et al., 2001), and exercise induced increases in insulin sensitivity (Richter et al., 1988) This is due to the higher rate of glycogen storage directly after exercise and slowing down to normal levels two hours post training. (Ivy et al., 1998) Over your week diet plan it shows that you are not eating regularly after training and are not replenishing your glycogen stores after your training and exercise. On day one you train at 9:30 for an hour and dont consume food for another hour and a half. Also on day 4 you train twice with no meal in between sessions. You should be aiming for atleast 50g of carbohydrates within the first hour post training (Coyle 1991)
The ingestion of dietary carbohydrate rapidly increases the level of blood glucose. The rate of glucose delivery depends on chemical structure of the food, which is summarized by the glycaemic index (GI). The glycaemic index was first proposed by Jenkins et al (1981) to describe the blood glucose responses to carbohydrate foods. A low GI food leads to a smaller rise of longer duration in postprandial glycaemia than a high GI one. (Foster-Powell et al. 2002).
The glycaemic index (GI) is a ranking of carbohydrates on a scale from 0 to 100 according to the extent to which they raise blood sugar levels after consumption. (Foster-Powell and Miller 1995)
Foods with a high GI are rapidly digested and absorbed and result in marked fluctuations in blood sugar levels. Low-GI foods, by virtue of their slow digestion and absorption, produce gradual rises in blood sugar and insulin levels. The effect of the GI of a pre-exercise meal on exercise performance has received substantial consideration in recent studies. Studies by DeMarco et al (1999) and Thomas et al., (1991) found consuming meals with a low-glycaemic response (GI < 40) to be associated with an improvement in exercise performance compared with the consumption of high-GI meals (GI > 70). These studies show the importance of low GI foods as a pre-training/ pre-competition strategy.
High-GI foods have been shown to impair fat oxidation during continuous, moderate-intensity endurance exercise (DeMarco et al., 1999, Wu & Williams 1999) this is due to an insulin spike related to consuming high GI foods.
A large increase in insulin inhibits adipose tissue lipolysis, limiting the availability and oxidation of free fatty acids (Horowitz 1997). According to Wee et al., (2005) Impairing fat oxidation following high-GI carbohydrate ingestion may increase reliance on muscle glycogen.
Your first meal before your first exercise session over the week consists of low GI foods such as porridge which is a good choice. White bread has a high GI which impairs fat oxidation because of the fast increase in insulin, you can try and substitute this for whole meal bread as its GI is lower.
As stated earlier, rowers should receive approximately 60% of their daily calories from carbohydrates in order to perform at their optimal level. Looking at your values for the week (appendix 1.4) your total carbohydrate intake is lower than what is required to maintain and sustain a healthy diet. As carbohydrates are the main source of fuel for athletes its availability can have an effect on performance (Moore et al., 2009).
Glycogen synthesis is similar over the day regardless of whether carbohydrate is consumed as large meals or as smaller snacks (Costill et al., 1981). Costill et al (1981) stated that studies examining 24-h recovery found that restoration of muscle glycogen is identical whether carbohydrate is ingested as two or seven meals, or as four large meals or 16 one-hourly snacks (Burke et al., 1996).
With this in mind your carbohydrate intake can be spaced out over several small meals or a lesser amount of big meals, depending on preference and also time. According to Blende (nd) an athlete should allow adequate time for food to digest, she states that eating a large meal should be allowed 4-6 hours, a small meal should take 2-3 hours and a liquid meal should take 1-2 hours.
Carbohydrate foods with a high glycaemic index provide readily available source of carbohydrate for muscle glycogen synthesis (Coyle 1991). Therefore post exercise and recovery meals should consist mostly of high GI foods, low GI foods should not make up more than a third of a post exercise meal. As stated earlier you are not consuming post exercise carbohydrates so an amendment to your diet should be high GI foods within an hour of exercise. This may include white rice, pasta or baked potatoes (Jenkins 2008)
According to Devlin and Williams (1991) after each bout of exercise, athletes should consume sufficient carbohydrate to replenish the glycogen stores. Coyle (1991) states that there is no difference in glycogen synthesis when liquid or solid forms of carbohydrate are consumed. Therefore sugar and starches, in both solid and liquid forms should vary depending on the timing and nature of the physical activity. Although athletes are advised to avoid sugary foods or drinks from 1 hour prior exercise up to 5-10 minutes before exercise (Burke et al., 2004) . This is to avoid a blood sugar spike which will be followed by a plunge due to the release of insulin which as stated earlier will prevents fat oxidation and may increase reliance on muscle glycogen. 5-10 minutes prior to exercise is too short a time for insulin to be secreted and secretion will be retarded during exercise.
Protein tends to be the favourite nutrient of athletes, especially strength athletes, because of its ability to stimulate muscle protein synthesis. It is essential for a well-balanced diet. A small amount of post-exercise low-fat protein helps athletes recover from multiple workouts and ongoing training more quickly (Ray & Fowler, 2004)
Skeletal muscle makes up 40% to 45% of body weight and is the largest storage site for amino acids. (Wu, 2009) It is suggested that per 2.2kg of muscle contains 70 to 105 g of protein, and to build a pound of muscle, it is estimated that 10 to 14 g of additional protein is needed each day (Rosenbloom 2000) Protein is an essential macronutrient as in addition to repair of damaged muscle tissue, protein is highly versatile and is involved in other functions that are crucial to sports performance such as cell regulation, muscle repair, immune function, neurological function, nutrient transport, and structural support. (Carrol 2000)
High-quality protein sources that contain all of the essential amino acids appear to be the most anabolic (Boirie et al 1997) this includes good quality food sources such as chicken, eggs, fish, beef with the fat cut off and also milk. Supplementation is also an added benefit for nutritional intake. A study by Boirie et al., (1997) showed that whey protein was highly soluble and the appearance of amino acids in the blood is fast, high, and transient. Casein clots in the stomach and delays gastric emptying, leading to a slower, lower, but more prolonged appearance. Although these may seem to have some added value to an athlete's diet studies by Duellman et al., (2008) suggest that it is a misconception and there is no added benefit from ingesting supplements compared to natural foods, but may be used if convenient.
According to Tipton and Wolfe (2004) the main determinants of an athlete's protein needs are their training regime and habitual nutrient intake. Yokota et al., (2009) has said that the recommendations for the requirements for protein intake amount usually to 1.2-2.0 g/kg of body mass per day in athletes. Inoue et al., (2008) also states that Protein requirement for athletes has been shown not to exceed 2g/kg/day. However the International Association of athletics Federation indicates that more than 1.7 g/kg/day protein is not necessary for any athletes. This is congruent with the American Dietetic Association (2006) and Rosenbloom (2009) who suggests that 1.2/1.7g per kg of mass is the amount of protein needed to improve aerobic capacity through mitochondria synthesis and build muscle mass and strength. Based on this information I would recommend your protein intake should be between 1.2 and 1.7g per kg of body weight depending on whether you are focusing on strength or endurance training. This would mean that your total protein intake should be between 116.4g and164.9g
According to Meltzer and Fuller (2005) one of the biggest myths for athletes is that large amounts of protein are required to build muscle. Your muscles can only use a limited amount of protein for growth, provided there is enough carbohydrate to fuel the strength-training required for the muscle to grow. Studies have shown that high-protein intakes do not have adverse effects on renal function (Rosenbloom 2009). Any excess protein will be broken down for energy and excreted as urea. Heaney and layman (2008) state that one concern with high-protein diets on bone health is the effect on acid-base balance. A high protein diet is acid forming and is associated with calcium loss in the urine. Calcium gets recruited from bone to buffer the acid and over time can contribute to bone loss. Ralston and Shaw (2008) state that the process of breaking down proteins also necessitates the excretion of water, so excessive proteins in the diet may affect fluid balance, which may also contribute to kidney disease, gout and arthritis. To counteract this it is suggested that adding fruits and vegetables to the diet can be an effective strategy.
The timing of protein intake appears to be the most important factor in achieving positive training adaptations. Several studies indicate that the period immediately after exercise is currently considered the ideal time for net muscle growth and recovery from exercise especially if combined with carbohydrates. It has been reported that a carbohydrate beverage with additional protein calories produced significant improvements to fatigue and reductions in muscle damage in endurance athletes (Saunders et al., 2004)
After resistance exercise, amino acid uptake is greatest in the first hour following amino acid ingestion and declined during the following 2 h (Miller et al., 2003). This is congruent with Levenhagen et al., (2001) who states that protein, carbohydrate and lipid supplement resulted in greater amino acid uptake when ingested immediately after cycling exercise than 3 h after cycling. As stated earlier you are not eating adequate post exercise meals in the mornings. However after your weight sessions you are eating adequate protein and carbohydrate meals, however on a few occasions you are eating a large chicken breast and having a protein shake within the same meal, this is unnecessary as the chicken breast should be adequate for your meal, also as stated earlier an excess in protein will be released in urine. A source of protein should also be eaten as well as carbohydrates after your workouts or bouts of exercise as this is the ideal time for recovery.
Athletes tend to neglect fats as a food source as it has a negative reputation (Enig 2005) however fats form an essential part of a healthy diet and all athletes need fat in their diet in order to perform well in their sport and in their everyday activities. Fat is a major fuel source due to its energy density and capacity for storage can provide energy during prolonged exercise for a longer duration (Hawley, Jeukendrup and Brouns 2000) one gram of pure lipid contains about 9kCal of energy, more than twice of that per gram of carbohydrates or protein as lipids have greater quantity of hydrogen (McArdle , Katch and Katch. 2008).
Leddy et al. (1997) found that an increased fat intake does not cause adverse effects on weight, adiposity, resting heart rate, blood pressure, serum triglycerides, total cholesterol, or low-density lipoproteins. This is given that calorific intake does not exceed expenditure, and rate of energy turnover remained high.
There are only two essential fatty acids or EFAs: alpha-linolenic acid, an omega-3 fatty acid, and linoleic acid, an omega-6 fatty acid. (Enig 2005) These two fats are essential because they can be used to make hormone-like substances called prostaglandins, which regulate a host of other functions in the body. However, these fats cannot be synthesised by the body and must be ingested for good health (Whitney and Rolfes 2008)
Whitney and Rolfes (2008) suggest that fat such as mono-saturated and polyunsaturated fats are essential for a healthy, active lifestyle. Omega-3 fatty acids are particularly helpful for athletes. It has been suggested that omega-3 may help to improve performance increasing blood flow to muscles and also by its ability to decreasing inflammation (Simopoulos 2002). Venkatraman & Prendergast (2002) state that the effects of omega 3 on performance has shown no effect on performance with trained athletes.
However (Price et al., 2000) suggest that essential fat can be beneficial to athletes as Increased intakes has been shown to reduce tissue levels of triglycerides, which in turn improves the sensitivity of insulin and reducing the risk of obesity and CHD. Clark (2001) showed that EFAs were able to direct glucose towards glycogen storage while at the same time directing other fatty acids in the body away from triglyceride synthesis (ie fat storage) and towards fatty acid oxidation. This is known as 'fuel partitioning'.
Saturated fats are bad for health and should be avoided when necessary. Eating saturated fats raise blood levels of harmful low-density lipoprotein cholesterol (Folsom et al 1995) and predispose individuals to heart disease (www.who.int)
Your fat intake over the week was far too high and you were consuming almost twice of your RDA on a few days. The fat that you were consuming was mostly saturated so we would be looking to lower this and to increase your intake of EFA's. Source of Omega 3 include oily fish such as mackerel and salmon, plant sources such as Linseed/Flaxseed oil, walnuts, Brazil Nuts, Hazelnuts, Pecans. Soya Bean Oil, Canola Oil, Rapeseed Oil, Linseed/Flaxseed Oil and also Egg yolks, both chicken and duck, are a good source of omega 3 fatty acids also
Vitamins and Minerals
Vitamins and minerals are knows as Micronutrients as they are needed throughout life in small quantities (Mcardle Katch and Katch 2008)
There are two groups of vitamins: Water soluble vitamins and Fat-soluble Vitamins. Water soluble vitamins such as vitamin B and vitamin C disperse in bodily fluids without storage in tissue to any appreciable extent. Generally an excess will void in the urine. Fat soluble vitamins such as Vitamins A, D, E, and K are dissolved and stored in the body's fatty tissue.
Fat soluble vitamins have no direct role in energy metabolism; they function in roles supportive of energy use (Lukaski 2004) Vitamin A and vitamin E act as antioxidants in reducing muscle damage and enhancing recovery from exercise. (Kanter 1994)
Because fat-soluble vitamins are stored for long periods, they generally pose a greater risk for toxicity than water-soluble vitamins when consumed in excess. Eating a normal, well-balanced diet will not lead to toxicity in otherwise healthy individuals. However, taking vitamin supplements that contain mega doses of vitamins A, D, E and K may lead to toxicity. (Hollick and Chen 2008)
Your diet plan shows that you are deficient in vitamin A where you were consuming half of your RDA and you should be consuming 3000 iu and C where you should be consuming 90 mg. Sources of Vitamin A include: beef, pork, chicken, turkey, fish (including cod liver oil) carrot, broccoli leaf and sweet potato. Vitamin C can be found in foods such as broccoli, blackcurrant, strawberry, orange, melon and cauliflower.
Vitamin D was also shown as deficient but this can be absorbed through sun light.
The below table shows information on the Fat soluble vitamins.
(Anderson and Young 2008)
Your vitamin B complex intake was all too high over the week. Overdoses of B complex can include Hot flashes, ulcers, liver disorders, high blood sugar, uric acid and cardiac arrhythmias.
Nelson and Cox (2000) states that Minerals are essential nutrients that your body needs in small amounts to work properly. We require them in the form they are found in food.
Minerals are necessary as they are required in; building strong bones and teeth, controlling body fluids inside and outside cells and helping to convert the food we eat into energy
These are all essential minerals:
Minerals can be found in varying amounts in a variety of foods such as meat, cereals (including cereal products such as bread), fish, milk and dairy foods, vegetables, fruit (especially dried fruit) and nuts.
Your mineral intake throughout the week was higher than the RDA. This can be hazardous as over doses of various minerals can cause Constipation, Kidney Stones, calcium deposits in body tissues. Hinders absorption of iron, calcium and other minerals.
Water is the most important nutrient; it serves as the body's transport and reactive medium.
It is also essential for thermoregulation of the body. Severe dehydration and/or heat stress can quickly lead to death. (Mcardle Katch and Katch 2000). Proper hydration is especially important during exercise. Adequate fluid intake for athletes is essential to comfort, performance and safety. The longer and more intensely you exercise, the more important it is to drink the right kind of fluids (Burke 1995)
Murray (2007) states that a decrease in body water from normal levels provokes changes in cardiovascular, thermoregulatory, metabolic, and central nervous functions that become increasingly greater as dehydration worsens.
Fluid losses do not only involve water, it also affects losses of sodium and other minerals (Candas 1989). It is recommended to drink sports beverage before, during and after exercise.
Institute of Medicine (2005) suggest that It is not really necessary to replace losses of sodium, potassium and other electrolytes during regular exercise since you're unlikely to deplete your body's stores of these minerals during normal training. However it is important to drink electrolytes because sodium and potassium, in a drink will reduce urine output, enable the fluid to empty quickly from the stomach, promote absorption from the intestine and encourage fluid retention. (Mcardle, Katch and Katch 2008)
If training or exercising is in hot conditions or exercise over 3 or 5 hours, then a sports drink with electrolytes would be very recommended.
As there was no indication of your water or fluid intake during exercise then this could not be measured. You should try and sustain healthy hydration levels before, during and after training. Burke (2007) set out this simple guideline to will help maintain hydration levels during your training, as during races replenishing fluids would not be possible.
Hydration Before Exercise
Drink about 400- 500 ml, 2-3 hours before exercise
Drink 250-300 ml 10-15 min before exercise
Hydration During Exercise
Drink 250-300 ml every 10-15 min during exercise
If exercising longer than 90 minutes, drink 250-300 ml of a sports drink (with no more than 8 percent carbohydrate) every 15 - 30 minutes.
Hydration After Exercise
Weigh yourself before and after exercise and replace fluid losses.
Drink 1 litre water for every 1 kg lost.
Consume a 4:1 ratio of carbohydrate to protein within the 2 hours after exercise to replenish glycogen stores
From reviewing your diet throughout the week (appendix 1) your calorie expenditure throughout the week was greater than your calorific intake. This will have a detrimental effect on your performance and will result in a lack of energy throughout the day. As there is a constant deficit then this will end up in weight loss which may include muscle loss. You should be looking to increase your calorie intake throughout the day to fuel you throughout the day and through your exercise sessions.