Introduction to Sport Nutrition & the Physiology of Exercise Flashcards
What are the types of physical activity?
- Endurance
- Flexibility
- Balance
- Strength
Define endurance
endurance exercises improve the health of your heart, lungs, and circulatory system
Define felexibility
stretching can imrpove your flexibility to make everyday activites easier
Define balance
balances exercises help prevent falls and can improve balance
Define strength
strength exercises can help you stay independent and prevent fall-related injuries
What is physical activity?
Any bodily movement produced by skeletal muscles that results in energy expenditure
- e.g., playing tag, gardening, sports
What is exercise?
A subset of physical activity that is planned, structured, and repetitve and has as a final or an intermediate objectvie the improvement or maintenance of physical fitness
- e.g., strength training at the gym, going for a run, joining a badminton team
What are sports?
Organized activites that have a set of rules that are played with opponents that result energy expenditure
- e.g., golf, volleyball, swimming
What happens to our digestive system?
- Blood flow is redistributed away from the digestive system toward skeletal muscle, the cardiovascular system, the skin
epinephrine and cortisol inc., inhibited GI motility and secretion - changes ensure energy is directed to system that supports physical activity but may temporarily impair digestion
What happens to our body temperature?
- Inc. metabolic activity in muscles produced heat
- blood flow to the skin inc. (vasodilation) to promote heat dissipation
- sweating begins to regulate and maintain body temperature within safe limits, but prolonged/intense exercise can challenge thermoregulation
Define sport nutrition
the performance of, and recovery from, sporting activities are enhanced by well-chosen nutrition strategies. Guidelines for the appropriate type, amount, and timing of intake of food, fluids, and supplements to promote optimal health and performance
- huge financial industry
How sports nutrition can enhance performance?
Preparation for sports
- fill glycogen stored prior to exercise
- hydration
Manage or alter body composition
- inc. muscle mass
- make a weight class
- reduce muscle load
**Maintain energy during exercise **
- supporting competition for the duration of an event
- providing energy boost
**Replenish nutrients lost during exercise **
- stimulate muscle growth
- refill glycogen stores
Maintain general health
- reduce injuries, likelihood of getting sick or chronic disease incidence
What are the local adaptations and impact for skeletal muscle?
Inc. mitochondrial biogenesis
- greater energy (ATP) production & availability
Inc. capillary density
- improves oxygen transport, which can help delay muscel fatigue
**Inc. lactate **
- used to produce ATP via gluconeogenesis
Inc. glycogen
- breakdown via glycogenolysis for energy (ATP)
Inc type I & II fibers
- stronger contractions & muscles endurane
What are the key nutrients for skeletal muscles?
Protein
Carbohydrate
Creatine
Magnesium
What are the local adaptations and impacts for the liver?
Inc. gluconeogenesis
- more ATP for muscles to use
Inc. glycogenolysis
- more ATP for muscles to use
What are key nutrients for the liver (i.e., glycoen stores)?
Carbohydrates
- build our glycogen storage
The athlete’s paradox
high insulin sensitivity in the context of simultaneously high intra-
muscular lipid content of skeletal muscle in well trained individuals
(i.e., high performance athletes)
Why would the athlete’s paradox be an advantage for an athlete?
**Quick Energy Source **→
- the body burns muscle fat first before using stored carbohydrates (glycogen); helps athletes sustain longer and more intense workouts
Improved Endurance →
- Endurance athletes (like marathon runners and cyclists) rely on fat as a fuel source during prolonged exercise.
- Having more readily available fat in muscles helps them last longer without running out of energy.
Better Metabolic Flexibility →
- Athletes can switch between burning fat and carbs easily.
In diabetics, the body struggles to use muscle fat properly, leading to insulin resistance.
What are the local adaptations and impacts for the digestive system?
**Reduced blood flow **
- reduced capability to digest food
**Stimulated gastric motilty **
- initiates gastric wave
What nutrients are key for the digestion system?
Protein
Fats
Fibre
What are the local adaptations and impacts for the epidermis (skin)?
Thermoreceptors send signals to the brain (when temperature rises)
- sweat glands secrete fluid to cool down the body
What are key nutrients for the epidermis?
Water
Electrolytes (sodium)
What are evidence-based sources of sport nutrition info?
Proven causation (or highly likely)
* Temporality, dose response, reproducible, underlying mechanism etc.
Consensus in the international community
* Can’t just work in one setting
Clear recommendations
* Often accompanied by an ‘evidence grade’
Transparency
* Know what was done, when, why and how
* Discuss of risk - toxicity limits
How are sport nutrition guidelines set?
Undergo a similar process to any other nutrient recommendation
* Panel of experts
* Review all available evidence
* Assess (or grade) what we ‘know’
* Set recommendations that support health & minimize risks
