diet and nutrition

Carbohydrates contribution to physical activity and sport, and sources

• main provider of energy for the body

• when broken down, carbs are converted into glucose, which is absorbed into the bloodstream to help provide energy

• sources: pasta, rice, potatoes

Proteins contribution to physical activity and sport, and sources

• aids tissue repair, and used to help muscles recover from intense exercise

• also a source of energy although a small one compared to carbs and fats

• sources: meat, cheese, nuts and milk

fats contribution to physical activity and sport, and sources

• major provider of energy during low-intensity exercise

• when glycogen stores are depleted stored adipose tissue is used to provided energy

• useful for insulation

• trans fat can be a source of energy, but too much can lead to increased levels of LDL cholesterol which can increase the likelihood cardiovascular disease

• sources: saturated fat includes butter, confectionary and cheese. Unsaturated fat includes avocados and nuts

minerals contribution to physical activity and sport, and sources

• have multifunctional roles and include calcium, iron and sodium

• calcium can help bone regeneration and protection

• iron aids the transport of oxygen to the working muscles, due to being a key component in haemoglobin and myoglobin

• sodium helps to maintain the electrolyte balance, improving cell maintenance

• sources: milk (calcium), beans (magnesium, cheese (sodium)

vitamins contribution to physical activity and sport, and sources

• vitamin C and D help to maintain the immune system, helping the body fight against infections and illness, keeping the athlete fit. also aids in strengthening bones

• vitamin B12 helps increase an athletes metabolism, contributes to the energy levels of athletes, and maintain a lean body composition

• B-complex vitamins can help reduce anxiety, which can improve sports performance that requires fine motor control as actions can become more precise and less affected by nerves

• sources: fruit, whole grains, seeds

fibre contribution to physical activity and sport, and sources

• plays a role in effective digestion, prevents overeating which can help optimise an athletes percentage body fat

• sources: brown rice, nuts, jacket potatoes, bran cereal

water contribution to physical activity and sport as a food group

• transport substances in the blood via osmosis

• thermoregulation

• supports cell function

• helps remove waste products

energy balance

energy input = energy expenditure

optimal weight

the body mass range that would allow for the strongest performance in a chosen sport and specific position

dehydration

• a harmful reduction in the amount of water in the body

• exercise performance can decrease when the athlete is dehydrated as little as 5% of their body weight

• side effects of dehydration include dizziness, headache, increased body temp and increased HR

problems if athletes get their energy balance wrong

• for an athlete to maintain performance they need to ensure they have efficient energy to perform and recover

• too much of one thing will create an energy surplus which will turn into excess body weight and a drop off in performance

• excess body fat could lead to a drop off in performance

• too little of anything will either mean a lack of available energy so a reduced performance and slower recovery which will inhibit future performances

• reduced body fat could lead to reduced performance or a slower recovery

sporting example of why a athletes in different position have different optimal weights

• forwards in rugby need to be heavier than backs to allow for more force production in scrums

• backs need to be lighter than forwards to be able to sprint at faster speeds

factors that determine how athletes achieve optimal body weight for performance

• adjusting energy intake

• adjusting energy expenditure

• appropriate use of weight management/dieting

• methods of fluid loss

definition of hypertonic drinks

• the glucose osmolarity of the drink is greater than that of the blood

carbohydrate content of hypertonic drinks

• 8g+ sugar per 100g

• 8%+

purpose of hypertonic drinks

• primarily to supply energy

• to supplement daily carbohydrate intake

• usually used in recovery

• replenish muscle glycogen stores

definition of isotonic drinks

• the glucose osmolarity of the drink is the same as the blood

carbohydrate content on isotonic drinks

• 4g-8g sugar per 100g

• 4-8%

purpose of isotonic drinks

• quench thirst

• provide energy

• replace fluids lost by sweating

• usually used during an event/performance

definition of hypotonic drinks

the glucose osmolarity of the drink is lower than that of the blood

carbohydrate content of hypotonic drinks

• 3g sugar per 100g

• 1-3%

purpose of hypotonic drinks

• replace fluids lost by sweating

• offer optimal hydration

• work best when an athlete is working at low intensities and needs a quick energy burst but not in large quantities

recommended hydration for sport

• before exercise, up to 3 hours before: 0.5 litres of water

• before exercise 30 mins before: 0.25 litres of water

• during exercise, every 15-20 mins: 200 ml of water

• after exercise, within 30 mins: 0.5 litres of water

how to prevent dehydration

• consume 1.5 times the amount of weight lost during competition/exercise

supplement defintion

any legal nutritional component which is consumed to improve performance or aid recovery

Creatine – physiological benefits

• Increases phosphocreatine (PC) stores in muscle

• Allows faster ATP resynthesis via the ATP-PC system

• Improves strength, power and repeated sprint ability

• Delays fatigue in short-duration, high-intensity exercise

• increases rate of recovery in muscle cells

Caffeine – physiological benefits

• Stimulates the central nervous system

• Increases alertness, focus and reaction time

• Reduces perceived fatigue

• Increases fat utilisation, sparing glycogen

• Enhances endurance and high-intensity performance

Sodium bicarbonate – physiological benefits

• Acts as a buffer against hydrogen ions

• Reduces muscle acidity (pH drop)

• Delays fatigue caused by lactic acid accumulation

• Improves performance in high-intensity anaerobic exercise

Whey protein – physiological benefits

• Provides amino acids for muscle repair

• Stimulates muscle protein synthesis

• Enhances recovery after exercise

• Supports muscle growth and maintenance

Cherry juice – physiological benefits

• Reduces muscle soreness (DOMS)

• Decreases inflammation

• Improves recovery between sessions

• Allows higher training frequency

Nitrate (beetroot juice) – physiological benefits

• Increases nitric oxide production

• Improves vasodilation and blood flow

• Enhances oxygen delivery to muscles

• Reduces oxygen cost of exercise

• Improves aerobic efficiency and endurance performance

BCAAs – physiological benefits

• Reduce muscle protein breakdown

• Support muscle recovery and repair

• Delay central fatigue

• May reduce exercise-induced muscle soreness

Glutamine – physiological benefits

• Supports immune function

• Aids muscle recovery

• Helps maintain muscle tissue during intense training

• May reduce illness risk during heavy training periods

• decrease inflammation

Antioxidants – physiological benefits

• Reduce oxidative stress

• Limit cell damage caused by free radicals

• Aid recovery

• reduces muscle damage

associated risks with supplements

• may list ingredients on label differently to how they would appear on the prohibited list

• counterfeit supplements, especially when purchased online

• may be contaminated with banned or other substances

• may contain more or less than listed on label

• may not work or have the opposite effect of what is claimed

• may be adulterated/contaminated

Aim of carbohydrate loading

to increase the quantity of stored muscle glycogen (energy) for an upcoming endurance event

protocol for carbohydrate loading

• 7 days before event: participation in endurance training. helps deplete the body of glycogen stores

• 3-6 days before event: lower than normal carbs in diet. Training is moderate. similar intensity but lower duration

• 1-3 days before event: carb intake greatly increased. training is greatly reduced to maintain built up stores

• - endurance event takes place

drawbacks of carb-loading

• feeling bloated

• digestive problems

• nausea

• weight gain

benefits of carb-loading

• increased glycogen store in the muscle and liver

• more energy available

• with glycogen stores maximised, carbs are more available as energy store

• last longer at a higher rate before fatigue sets in

• maintain pace for longer

• should prevent athletes from hitting a wall

• marathon lasts over 2 hours and body only typically stores enough glycogen for 90-120 mins

fuelling after an event - 2 hour window of opportunity

• due to a higher metabolism following exercise than at rest, athletes should aim to:

• replenish lost glycogen and protein stores (food)

• rehydration (often hypertonic drinks that replace lost sugars and salts)

carbohydrate intake after an event

• quick consumption post-workout

• shouldn’t exceed 2 hours after activity

protein intake after an event

• optimal within 2-3 hours of exercise

• immediate intake - amino acids