exercise phys Flashcards
what is vasodilation?
increase size
what is vasoconstriction?
decrease size
4 ways of gaining heat?
hormones
environment
muscular activity
metabolic rate
4 ways of losing heat?
- Conduction
- Convection
- Radiation
- Evaporation
what is double heat load?
Heat is produced within the muscles when they are working, and also is present in the environment
conduction?
is the heat exchanged by two objects that are in contact with each other.
convection?
is heat exchange by contact between an object and fluid that is flowing. This occurs when heat is carried away from the body by air or water currents.
radiation?
occurs when heat is transferred from a warmer body to the cooler surroundings without physical contact.
evaporation?
is the cooling of the body as a result of the vaporisation of sweat.
what effects the rate of sweat?
Gender (males sweat more than females)
The number of sweat glands
Body surface area (Increased SA increased sweating)
How fit they are (Increased fitness increased sweating
factors affecting conduction?
Difference in temperature between the two objects (heat flows from hot to cold)
Surface area (Increased surface area increased heat loss)
Thermal conductivity of material (e.g. metal is a good conductor of heat)
factors affecting convention?
The speed and temperature of the air/water. E.g. if a breeze gets stronger, the heat loss occurs faster.
The layer of warm air that continually surrounds our body is displaced by cold air when air temperature is lower than skin temperature
heat loss by exposing more of their body surface area to the cooler surrounds
factors affecting radiation?
Radiation accounts for 60% of heat loss from body at rest on a cool day.
- Heat loss occurs when a person’s core temperature is higher than the ambient temperature.
- Heat gain occurs when a person’s core temperature is lower than the ambient temperature.
explaining evaporation? (4)
- At rest, evaporation accounts for 25% of heat loss. When active, this can increase up to 80%.
- When the body exercises, muscles create heat.
To avoid overheating, the body uses blood to help regulate temperature. - Heat is transferred to the skin’s surface via the blood (vasodilation of vessels), where it is released as sweat.
Evaporation of the sweat on the skin creates a cooling effect. - The cooled skin then cools the blood at the surface, maintaining the body’s core temperature.
- better in dry heat conditions (over humidity)
excessive sweating
Excessive sweating leads to a loss of body fluids, and when level of body fluid drops, the body’s core temperature increases.
It is this gradual dehydration that leads to heat exhaustion and heatstroke.
Sweat loss can reach 6 – 10% of body mass
> 2% generally means performance and thermoregulation are compromised
3 ways of heat transfer
- environment
- ambient temp
- convention
- radiating surfaces
- relative humidity
- age
- childern dont sweat as much
- physiological state
- how much work is performed
- hydration state
dehydration
occurs when the amount of water leaving the body is greater than the amount of water being taken in.
cardiac drfit (explanation)
creates a competition for blood flow.
- The muscles and vital organs require blood flow to sustain energy metabolism
- The skin requires blood flow so it can release heat to regulate body temperature
- The blood flowing to the skin cannot help to transport oxygen to the working muscles, which can impact performance
hyper-hydration
Involves increasing the body’s fluid stores by consuming extra fluid prior to an event
pre exercise how much water
1L prior to exercise is recommended
600ml 3 – 4 hours before game/competition
400ml just prior to game to prime the stomach
Avoid caffeine – it is a diuretic & increases fluid loss
Allows the athlete to sweat more before performance is inhibited
water during exercise
Drink ~200ml of water every 15 minutes during activity. This is influenced by environmental conditions and exercise intensity.
water post exercise
Want to replenish back to pre-exercise weight
For every litre of sweat loss, consume
1.5L as you will lose some of this through urine
Consume slightly salty fluid to keep osmolality higher so you don’t urinate as much.
hyponatremia
is an abnormally low concentration of sodium (salt/electrolytes) in the blood
what is heat acclimatization
is when heat tolerance is improved by repeated exposure to hot environments.
how to acclimatise to heat
How long?- The first sessions should be ~15-20 mins, and be light to moderate activity
This should increase to 45 – 60 mins daily for ~ 8 – 9 days with an increase in exercise intensity & duration.
5 – 10 days living and training in heat is recommended.
Where?Athletes who are unable to use natural acclimatisation should use climate chambers, saunas or sweat clothing.
When?Should be completed 4 – 6 weeks prior to competition and then 2 sessions per week leading up to competition to maintain the benefits
major adaptations to heat
sweating earlier
cardiovascular
what happens to sweating when heat acclimatized
Increase blood plasma volume (more fluid stored in the blood), increases the length of time to dehydration
Increases sweat rate
Start sweating at lower core temperature
Sweat becomes more dilute and is distributed over the body more effectively
what happen to the cardiovascular system when heat acclimatized
They have a lower HR than an unacclimatised athlete
The lower core temperature also reduces the body’s need to send blood to the skin for cooling, resulting in a greater % of Q going to the active muscles.
methods to cope with exercising in the heat
hydration
clothing
pre cool body temp
modify training
Clothing to where in the heat
Wear loose fitting, light coloured clothing to permit free circulation of air between the skin and the environment, promoting convection and evaporation from the skin.
how can you pre cool body
Pre cool core body temperature via a range of methods including ice towels/vests, immersion in cold water, drinking iced water/slushies
modify training for training in the heat
Frequent rest breaks. Avoid training during the heat of the day i.e. morning sessions
or early evening Reduce training volume/intensity/duration
altitude
True altitude is the actual elevation above mean sea level.
how altitude effects performance
The alveoli are low in O2 & low in CO2
The venous blood is also low in O2 & high in CO2
Therefore there is only a small pressure differential, making it difficult for diffusion of oxygen from the alveoli into the capillaries
altitude acclimatization
Altitude acclimatisation describes the improved physiological response to altitude hypoxia. Hypoxia is a deficiency in the amount of oxygen reaching the tissues.
3 methods to altitude acclimatization
Living high and training low
Living and training high
Living low and training high
living high and training low
Involves daily intermittent exposure to artificial altitude environments whilst maintaining normal training intensities.
This is more beneficial because athletes can still maintain their training intensity whilst getting added benefits of altitude exposure & the associated physiological adaptations.
living high and training high
The athlete lives at high altitude to achieve the physiological benefits of decreased oxygen concentration and trains at altitude to obtain adaptations.
This usually requires the athlete to go to at least 2000 – 3000m above sea level, and live and train for about 3 – 4 weeks.
altitude sickness is as well
This method is best suited to preparing teams to compete at altitude, not to compete at sea level.
living low and training high
Athletes live at sea level but train in hypobaric chambers or altitude tents to simulate a hypoxic environment.
There is no evidence that this method is effective in gaining the chronic adaptations achieved by using the ”live high, train low” method.
acute adaptations to increasing altitude
increased respiratory rate
increased tidal volume
increased nausea, head ache
increased HR and Cardiac output during rest
decreased plasma volume
chronic adaptations from altitude training
increased haematocrit (% of red blood cells in the blood)
increased mitochondria
increased aerobic enzymes
increased capillaries
myoglobin
preparing for competition at altitude
increase recovery
extended tapering
training intensity must decrease
strict fluid replacement
the bodys response to the cold
peripheral vasoconstriction
shivering
piloerection
peripheral vasoconstriction
Redirection of blood flow away from the skin surface towards the body’s core, to try and minimise heat transfer from the blood to the environment
shivering
Involuntary muscular contractions to produce heat (more glycogen used)
Piloerection
When the hairs on the body stand on end and trap a warm layer of air close to the skin to help keep the skin surface warm.
performance in cold weather
Increase submaximal VO2 at given exercise intensity
Shivering may lead to early glycogen depletion
Fine motor skills deteriorate
Reduced sensation in hands and feet due to vasoconstriction
wind chill
The apparent temperature felt on the skin due to the combination of wind and ambient temperature.
Wind increases heat loss because of convection, as it constantly removes the layer of warm air surrounding the body.
risk of dehydration in the cold
Inhaled air is very cold and dry, it needs to be warmed and humidified, meaning a lot of fluid is lost via respiration.
The sensation for thirst is reduced, so voluntary intake of fluid reduces.
hypothermia
Occurs when the body’s temperature falls below 35 degrees
cold acclimatization
7 – 10 days prior to competition
Allows the chance to experiment with clothing/suitable warm-up
Psychological adaptation can occur
Athletes attempt to train their bodies to generate heat and better prevent heat loss,
methods to help cope with the cold
Experiment with the length of the warm-up
Experiment with layered clothing
Psychological acclimatisation
Ensure adequate fluid replacement
what effects energy requirements
Age
Gender
Level of physical activity
Periods of growth
protein
Growth of muscle tissue
Repair of muscle tissue
Production of red blood cells, hormones & antibodies
Contribution to ATP production when CHO & fat stores are depleted
fats
Fats (stored as triglycerides in muscle cells, and broken down into free fatty acids) are the major fuel source during rest (60%) & during light to moderate exercise.
As exercise intensity increases, the relative contribution of fat as a fuel source decreases as the time taken to convert fat to a usable fuel source is too long to meet the high demands of the exercise.
Trained athletes can utilize fats as a fuel source at higher intensities
carbohydrates
It is converted to blood glucose, leading to a rise in insulin
Excess blood glucose is converted to glycogen
Glycogen is stored for future use in the muscles and liver
high gi
break down quickly
have an immediate effect on the blood stream
low gi
have slow release
releasing glycogen steadily over time
rebound hypoglycaemia
Immediately after eating high GI foods, there is a rapid rise in blood sugar levels resulting in too much of the hormone insulin being released into the blood, lowering blood sugar levels
carbo loading
is a nutritional intervention aimed at delaying the depletion of glycogen stores. It occurs when the athlete increases the amount of CHO consumed prior to competition with the aim being to store extra glycogen in the liver and muscles. There are two main methods to load.
fueling energy systems
At low intensity/rest, stored fats are the main fuel source.
As intensity of exercise increases, the contribution of muscle glycogen increases to meet the more immediate demands for fuel.
There is enough glycogen stored in the muscles to fuel up to 90 minutes of exercise, depending on intensity. Athletes ”hit the wall” when muscle glycogen runs out.
When muscle glycogen stores run out, the stored liver glycogen becomes the primary fuel source allowing exercise to continue but performance starts to diminish.
Depletion of liver glycogen is referred to as ”bonking” and affects the brain, so decision making ability is affected.
Fats now become the primary fuel source & intensity of exercise is reduced as fats are more difficult to break down
Depletion of fats results in protein being used as a fuel source. This is only likely to occur in ultra endurance events
glycogen sparing
the ability of an athlete to spare glycogen supplies by using an alternative fuel source during physical activity
nutrition pre event
The meal should be consumed 1 – 4 hours prior to competition, and consist of low GI foods for slow release of glucose into the bloodstream.
The body tends to use the foods most recently digested as an energy source, which assists with glycogen sparing. Pasta, all bran cereal, apples and lentils are good options.
Consume ~600 – 800ml fluid 1 hour prior to the event to assist with hydration.
nutrition during event
For events lasting longer than 60 minutes, CHO consumption is important to avoid depletion of stored glycogen.
Consuming high GI food can assist in glycogen sparing.
200ml of fluid every 15 minutes
30 – 60g of high GI CHO per hour
nutrition after the event
Immediately following exercise, the muscles are most responsive to topping up glycogen stores.
As a result, due to consumption of high GI, an increase in muscle glycogen storage occurs.
It takes at least 24 hours for glycogen replenishment after heavy endurance work.
The amount of CHO replenishment will depend upon the intensity and duration of the exercise
Consuming low/medium GI foods for the next 24 hours completes the replenishment of glycogen stores
2 methods of carbo loading
3 day method
1 day method
glycogen sparing can be achieved by
training
caffeine
pre event meal
during the event meals
what are the performance enhancing strategies
anabolic steroids
stimulants
protein powders
anabolic steroids (illegal) pos and negs
ads:
Increase the performer’s size, strength & power
Decreases recovery time
Stimulates protein synthesis
Improved rate of tissue repair
negs:
Deepening of the voice
Acne
Liver disease/cancer/dysfunction/damage
Raised cholesterol
Cardiovascular risks including hypertension (high blood pressure)/heart attack/stroke
stimulants (illegal)
ads:
Increases awareness
Increases aggression
Masks fatigue, improving anaerobic performance
negs:
can cause panic attacks
can cause paranoia
increased blood pressure (hypertension)
increase chance of heart attack/disease/stroke
dehydration
impaired heat regulation
stimulants (legal) pros and cons
ads:
Acts as an analgesic, reducing the perception of effort
Stimulates the CNS, increasing alertness
Are thought to also create a glycogen sparing effect through the oxidation of free fatty acids
dis:
Potent diuretic - this may cause an unnecessary loss of fluid
protein powder (pros and cons)
ads:
Increased protein consumption may assist in increasing muscle bulk
use protein as a fuel source.
Improve the rate of recovery
Increase muscle mass only if the athlete is undertaking a resistance training program.
dis:
Colon cancer
Kidney damage
Increased water retention
atp-pc
ATP lasts about 1 – 2 seconds when stored in the muscles.
PC (Phosphocreatine) lasts about 7 – 8 seconds when stored in the muscles.
Combined, they last ~10 seconds and are used for power sports: sprinting, jumping, throwing, weight lifting.
ATP-PC supplies recover quickly (3 – 4 minutes).
lactic acid system
ATP is resynthesised by the breakdown of carbohydrate (glucose).
This serves as the back up energy system for both the ATP-PC and aerobic systems.
Used for sustained sprint or muscular endurance activities usually lasting between 45 – 60 seconds. E.g. a 400m sprint or 200m swim.
Requires ~60 – 90 minutes between events for optimal recovery.
Active recovery (such as slow walking) results in a faster removal of lactic acid than passive recovery.
aerobic energy system
Aerobic – requires oxygen.
ATP is resynthesised by the breakdown of carbohydrate, fat and protein.
This is the all day, every day energy system.
CHO is the preferred energy source during high intensity exercise as it requires less energy to produce ATP than fat.
Stored glycogen in the muscles is broken down into glucose.
When the glycogen in the muscles is depleted, glycogen in the liver is used.
As long as you continue to provide your body with energy supplies, this energy system could last forever.
during exercise (energy systems)
At the commencement of exercise, all three energy systems start contributing to the production of ATP at the same time.
periodisation
is the planning, well in advance, of training variables to achieve optimal performance at the most crucial times.
annual training plan
The annual plan spreads across the whole year. The Purpose of the annual plan is to ensure optimal performance occurs at the right time by:
Applying training principles over the year.
Applying a taper prior to competition.
Monitoring of fatigue and recovery to prevent overtraining.
macrocycles
large training block which last at least 3 months
microcycle
microcycle is a smaller unit of time, normally between 3 – 10 days long but can be as short as one day.
A microcycle is often one training week.
pre season general
objective;
Pre-season training is designed to build a suitable aerobic base and skill level leading into the competition.
High volume training with low/medium levels of intensity
Continuous, interval & fartlek training
Flexibility training
Basic skill work
Fitness testing
pre season specific
objective;
Develop game specific fitness, skills and strategies
Training may need to be personalised depending on players/positional needs.
Reduced training volume with an increase in intensity occurs during this time.
High intensity interval training
pre competition stage
objective;
to reach peak match condition.
Focus at training moves to match specific intensities, durations & tactics.
Application of the principle of specificity is crucial.
Continue to develop appropriate mental skills.
Intensity of training increases.
Volume of training decreases.
Recovery between sessions is essential.
Play trial games
objective of competition stage
objective;
fitness is maintained, dependent on individual situations
Players at optimal level of skills and fitness.
Focus on psychological and tactical preparation.
Recovery sessions critical, particularly after games when players are often sore.
Constant peaking and tapering are critical in allowing players sufficient recovery during the season.
off season
Training volume and intensity significantly reduced to allow for full physical and psychological recovery.
Older players in particular find this time crucial in allowing the body to recover.
Aerobic fitness should be maintained to avoid detraining through involvement in enjoyable activities e.g. surfing or different sports.
Monitor nutrition to ensure a return to active participation close to playing weight.
Opportunity for corrective surgery and rehabilitation.
Specialised programs to correct structural or skill deficiencies
tapering
the strategy of reducing volume and increasing or maintaining intensity in order to allow full recovery prior to competition.
peaking
is planning training in such a way that optimal performance is achieved at the appropriate time.
tapering for peak performance (how long before)
Tapers are normally between 4 – 28 days long, depending on the type of event being tapered for, and the individual
over training
is a physical, behavioural and emotional condition when exercise (volume & intensity) exceeds their recovery capacity (imbalance between work and rest)
signs and symptoms of over training
psychological:
decreased self esteem
depression
loss of interest in the sport
physiological:
general soreness
weight loss
increase injuries
behavioral:
decreased effort
performance drops
gives up
causes of over training
Workload too high
Lack of variety in training sessions leading to staleness
Insufficient recovery from injury
Incorrect application of progressive overload principle
Insufficient recovery methods
preventing overtraining
Have variety in the training sessions.
Cross-training achieves this.
Keep well-hydrated.
Reduce training load
maintenace
is when fitness levels are sustained, but not developed or overloaded.
soft tissue injury
increase protein intake
fatigue
is when an athlete is not able to work at normal levels but not as a result of injury or illness.
3 key areas of recovery
nutritional recovery
physical recovery
psychological
3 physical recovery strategies
hydrotherapy
massage
hyperbaric oxygen therapy
hydrotherapy is
Includes movement in water, or alternate use of hot/cold ice baths.
Non weight bearing activities are effective in the removal of waste products.
Reduces tissue damage and pain.
Contrast baths operate on the principle of increasing blood flow by constricting and dilating blood vessels
massage
Aids recovery physically and psychologically.
Should occur 1 – 2 hours after training/competition.
Helps relax the muscles and clear away lactic acid by increasing blood flow
hyperbaric
Used to treat soft tissue injuries and promote recovery.
Athletes breathe in pure oxygen to increase oxygen concentration in the blood.
Results in more oxygen being delivered to fatigued muscles, and a more rapid recovery process.
2 nutritional recovery
Replenishment of fluids and electrolytes
Replenish depleted glycogen stores
4 ways of monitoring recovery
training logs
lab testing
observation
questionnaires
