Sports science topic A

Phosphagen system

• Main role: Provides ATP immediately for very short, explosive exercise

• Type: Anaerobic

• Fuel: Creatine phosphate (PC)

• Site: Sarcoplasm

• Enzyme: Creatine kinase

• Process:

  • ATP —> Energy + ADP— Creatine Phosphate + ADP —> (through creatine kinase) ATP + Creatine

• ATP yield: 1:1 ATP

• By products: None

• Recovery: Fast (50% in 2-3 seconds and 90% in 2-3 mins)

• Intensity: Very high

• Sport use: Sprint start, jump

Glycolytic system

• Main role: Produces ATP quickly when exercise is intense and lasts longer than the phosphagen system can support

• Type: Anaerobic

• Fuel: Carbohydrates

• Site: Sarcoplasm

• Enzymes to know: PFK and LDH

• Process: Glycogen—(Glycogenolysis)—> Glucose-1-phosphate —(glycolysis through PFK)—> ATP and Pyruvate—(LDH)—> Lactate + H⁺

• ATP yield: 2 net ATP

• By-products: Lactate and H⁺

• Recovery: Requires lactate removal

• Intensity: High

• Duration: About 2-3 minutes

Advantages

• Produces ATP quickly

• Works without waiting for oxygen supply

• Uses carbohydrate, which is a fast fuel source

Disadvantages

• Low ATP yield

• Produces fatiguing by-products

• Cannot support exercise for long

Glucose oxidation

• Main role: Produces larger amounts of ATP aerobically from carbohydrate

• Type: Aerobic

• Fuel: Glucose or glycogen

• Main location: Mitochondria after glycolysis0

• Process: Glycogen—(glycogenolysis)—> glucose-6-phosphate—(glycolysis through PFK)—> pyruvate—(available oxygen)—> acetyl-CoA—(Krabs cycle + H₂O + CO₂)—> H⁺ + heat —(NADH)—> Electron transport chain

• ATP and products

  • Total ATP yield: 38 ATP

  • ATP from ETC: 34 ATP

  • By-products: Water, heat, carbon dioxide

• Duration: Up to 2 hours

• Recovery: 24-48 hours

Fat oxidation

Fat oxidation

• Main role: Produces very large amounts of ATP aerobically for long-duration exercise

• Type: Aerobic

• Fuel: Fats, mainly triglycerides

• Site: Mitochondria

• Enzyme to know: Lipase

• Process: Fat stores —> Triglycerides—(lipolysis through lipase)—> fatty acids—(Via carnitine transport) —>beta oxidation—> Acetyl-CoA—(Krabs cycle) —> ETC (slow but high yield) + H₂O + CO₂+heat

• ATP yield: 100+ ATP overall

• By-products: Water, carbon dioxide, heat

• Excess fat: Stored as triglycerides in adipose tissue

Lactate inflection point/Anaerobic threshold definition

Point at which blood lactate begins to substantially accumulate above resting concentrations during exercise of

Happens when lactate production > lactate clearance

Marks transition from moderate to high intensity

OBLA

When lactate inflection point (typically 4 mmol/L of blood lactate) is reached causing rapid production of lactate and hydrogen ions = pain increases and inhibited muscle contraction

What happens to lactate

It is not just waste as it can still be used by the body by converting it to pyruvate and then used in aerobic pathway then entering mitochondria and used in Krebs cycle

Clearance pathways (lactate)

• Approximately 75% of lactate is cleared by oxidation

• Other 25% is converted back to glucose and stored in the liver and kidneys by gluconeogenesis

Critical power

• Maximum power output a person can sustain for prolonged periods without becoming fatigued (ie highest sustainable power WITHOUT fatigue

• The lactate inflection point is usually expressed as the % of VO₂ max at which it occurs

Trained vs untrained individuals and LIP

Untrained

• LIP is around 50-60% of VO₂ max

• Tolerance to this point can increase with training

• Training can improve the athletes ability to clear lactate and use it as a fuel source

Trained

• In elite endurance athletes can occur at 70-80% of VO₂ max

• If 2 Athletes have the same VO2 max, the athlete with higher LIP will have better endurance performance

LIP application to sport

• For trained athletes, working near their LIP is an effective way to push the body and increase % of VO2 max at lactate threshold

• It can be demotivating for untrained athletes because discomfort appears earlier at lower intensity

• This info can be used to set individual training zones.

Explain Specificity in training design

Training adaptations are specific to the type of activity being done, including the muscles used, volume, intensity and therefore the energy system being trained.

Example for a 10km swimmer- high volume, lower intensity, mainly oxidative system

Progressive overload definition

Systematically increasing the demands on the body so improvement continues

There are 3 components— frequency, intensity and duration

Frequency- How often training happens

Intensity- level of stress during exercise, can be measured in RPE, heart rate, increasing reps/sets and decreasing rest time

Duration- How long exercise lasts

Recovery in training design

Adequate rest and recovery are essential for the body to adapt to training and avoid negative outcomes. Without enough recovery, overtraining can happen.

Fitness-fatigue model

Idea that performance may drop straight after training and can stay reduced for a few days but then rebounds and improves. Explains why recovery is necessary

Variety

Changing one or more variables in training program. Helps keep training effective while still targeting the same physiological goals

Reversibility

Any adaptation gained through training is lost if training stops

Periodization

A systematic training method that breaks training that breaks training into phases so that the athlete peaks at the most important time of the season

Periodization main phases

• Post season/transition

  • Allows physical and mental recovery while maintaining an acceptable level of fitness, full rest is risky because it can cause reversibility

• Pre season

  • Prepares the athlete physically, psychologically, technically and tactically and lasts 3-6 months

• Competition phase

  • Main goals are to maintain general condition, keep improving, perfect techniques, volume is generally reduced so athlete is not fatigued

2 parts of pre season

General phase- Focuses on basic fitness and physical conditioning so athlete can tolerate greater later volume and intensity

Specific phase- Becomes more sport specific and focuses on skills and technical requirements often including friendlies or exhibition games

What are the different types of cycles in training design

Macrocycle- The WHOLE season or year plan including all major phases of training

Mesocycle- A specific training block inside a phase, designed for one main goal such as improving cardiovascular endurance

Microcycle- The weekly training plan, including all training and recovery sessions

Measuring progress in training

• Baseline values- Training effectiveness is judged by measuring baseline values at the start and over time as athlete progresses

• Baseline data helps set intensity, volume, specificity, spot injury risk, and track improvement objectively.

Training load categories

External indicators- Objective measures like distance, power output or repetitions

Internal indicators- Are physiological stress markers like heart rate, oxygen uptake, blood lactate and RPE

Why does knowing current fitness level matter for training design?

Programs must be individualized to the person, not just the sport.

What do coaches and individuals need to consider when designing a training plan?

• Current fitness level

• Age

• Sex differences

• Baseline values

How can age change a coach´s approach to training plans?

Children 6.12: Emphasize fun, skill based activities, motor skill development and low resistance because coordination is still developing and growth plates are still forming

Teens 13-17: Focus on technique, foundational strength and mobility while monitoring volume and intensity because of rapid growth and injury risk if overloaded

Adults 18-40: Optimize sport specific strength, power and endurance with progressive overload

Older adults 40+: Prioritize mobility, functional strength and injury prevention

How can sex difference change a coaches approach to training design?

Females:

• Have greater risk of ACL injury due to larger Q angles, hormonal fluctuations and neuromuscular activation differences

• Are more quadricep dominant which impacts landing stability

Males:

• Higher VO₂ max, faster recovery due to higher protein synthesis, better thermoregulation due to higher sweat rate, faster muscle gain from higher testosterone, more adductor injury risk from imbalance, and less hip mobility

Adaptation and fatigue for individuals

Adaptive responses to training like strength, endurance, VO₂ max and hypertrophy depend partly on genetics with high responders improving a lot while low responders improve little or slowly which is why training must be individualized. Other factors like sleep, nutrition, motivation and intensity all have an imapact.

Explain under training vs overtraining

Under training- Not enough stimulus to improve performance because training is too infrequent or too low in intensity

Over training- Trying to do more training than the athlete can physically or mentally tolerate causing deterioration in performance and health

What is overreaching and non function and functional overreaching

Overreaching is going beyond the athletes current limit of tolerance for a short time often during a hard block or training camp.

Functional overreaching is the practical overreaching, useful with adequate recovery and return of performance after a few days whereas non functional has symptoms lasting longer and impairs performance for weeks

What is overtraining syndrome

Overtraining is the process, while overtraining syndrome (OTS) is the resulting condition.

Main indicator is fall in performance with other indicators as sleep disturbance, raised resting heart rate, persistent fatigue and decreased appetite

Delayed muscle on set(DOMS) vs OTS: DOMS is acute lasting about 24-72 hours whereas OTS soreness is chronic and not relieved by rest

Reduced appetite can also create a severe energy deficit, forcing greater reliance on less efficient fuels.

Menstrual cycle follicular phase and its training implications

• Hormones:

  • FSH and LH rise alongside estrogen, whereas progesterone stays low

• Training implications

  • High estrogen = glycogen sparing and greater fat use + increase injury risk because of joints reduced stiffness

Menstrual cycle luteal phase and training implications

• Hormones: Progesterone is higher between ovulation and menstruation

• Training implication: Higher progesterone = Raised core temp, increases hydration demand, affects fuel availability and may bring premenstrual symptoms such as bloating, cravings and mood changes

Examples of training adaptations specified to menstrual cycle

• Progesterone may mean cooler envrionments, earlier training, focus on hydration and longer aerobic work.

• Estrogen may support longer steady-state endurance work but also requires attention to mobility, dynamic stretching and joint comfort

Physical activity recommendations

Adults:

• 150 minutes of moderate intensity exercise per week

• 2 strength training per week

• To prevent obesity— 150-250 minutes per week

• Complete 2 strength trainings per week

• MINIMUM of vigorous activity— 75 mins per week

Teens:

• Minimum of vigorous activity is 210 minutes per week

Pathogens and what happens when they enter the body

Disease causing microorganisms, when detected in body they are met with an aggressive localized immune response

Exercise effect on the immune system

Moderate exercise:

• Up to 45 minutes at moderate to vigorous intensity, is generally beneficial

• Supports normal immune function and may lower the risk of respiratory infection.

• Arduous exercise lasting over 2 hours can be immunosuppressive

• Immunosuppression is a state where the bodys immune system is weakened and less effective at fighting pathogens

Fight or flight

Activates cardiovascular, musculoskeletal and immune systems preparing the body for threat or injury, giving

Stress hormones and impacts

Stressors like exercise trigger a biological response consisting of norepinephrine, epinephrine and cortisol

This response causes a rapid redistribution of white blood cells (leukocytes) from the blood to tissues such as skin, lungs and intestines resulting in immune protection from possible entry or injury sites.

Chronic stress lasts for weeks or months and can have more detrimental effect then acute stress

Norepinephrine, epinephrine and cortisol

Norepinephrine - Acts as both a neurotransmitter and a hormone, heightens alertness and directly regulates bp

Epinephrine- Primarily a hormone, causes immediate intense physical reaction by increasing HR, boosting energy, and preparing muscles for quick actions.

Cortisol- Helps manage and recover from stress by regulating metabolism and immune system, excessively high levels over time can lead to chronic stress

J shaped curve

Shows relationship between the risk of upper respiratory tract and exercise volume.

Inactivity = high URTI, regular training = low risk, competition = moderate risk, overtraining = high risl

S shaped curve

Refers to how elite level athletes are able to perform high intensity with no increase in URTI rate

Open window theory in active lifestyle

Discusses how there is a window of immunodepression lasting about 1-72 hours, with repeated exercise potentially increasing vulnerability.

Energy balance

• If energy is greater than expenditure, weight gain occurs

• If energy intake is less than expenditure, weight loss occurs

• If energy intake equals expenditure, body mass stays stable

Hormones responsible for apetite

Apetite suppressive- Leptin

Apetite stimulant- Ghrelin

Benefits of physical activity

Improves:

• Balance

• Sleep quality

• reduces of obesity

• bone health

• muscular and immune system function

• risk of non-communicable diseases

• mental health

Risks of inactivity

• Osteoporosis

• Obesity

• Hypertension

• Cardiovascular disease

• Type 2 diabetes

• hypokentic disease - disease associated with sedentary lifestyle

How can athletes protect their immune system?

• Manage training load and limit the weekly load increases to 5-10%

• Follow hard sessions with easier sessions

• Plan a recovery week every 2-3 weeks

• Aim for at least 7 hours of sleep nightly

• Good sleep hygiene

• Match energy intake to expenditure

• Eat balanced diet

Mood vs emotion

Mood- Longer lasting feeling, hours to months

Emotion- Short lived responses to stimuli

Effects of excercise on mood

• Regular excercise fosters a more positive mood

• More happiness and energy

• Less tension, fatigue and anger

• Improves self esteem through improved self perception

• Better sleep quality

• More positive effects on menstruation, pregnancy and menopause

Depression and anxiety in relation to excercise

• Physical activity is linked to lower levels of depression

• Exercise is described as an effective treatment for depression

• Clinical depression is long term and is different from short lived on clinical depression

• Less clear link between excercise and reduction in anxiety

Physiological explanations for excercise improving well being

• Thermogenic hypothesis- Increased body temp during and after exercise may improve mood

• Cerebral blood flow- Excercise increases blood flow and oxygen delivery to brain

• Endorphin hypothesis- Increases endorphins, which reduce pain and promote well being

• Serotonin hypothesis- Exercise may increase serotonin which is linked to happiness and well being

• Increase in norepinephrine which can improve alertness and vigor

Psychological explanations for excercise improving well being

• Feel better effect- Mastering physical tasks can improve self esteem and body image

• Distraction- Exercise distracts from daily stressors

• Social interaction- Group excercise and sport can improve mood through positive social contact

Excercise intensity in relation to health

Intensity should increase gradually over time, following the principles of specificity and progressive overload. This allows muscles, bones and joints to adapt and strengthen.

Increasing intensity too fast can lead to injury or strains

Exercises influence on pregnancy

Staying active during and after pregnancy proves to be safe and beneficial for mother and baby, with benefits including reductions in:

• excessive weight gain

• anxiety depression

Pregnant individuals should aim for at least 150 minutes of moderate intensity aerobic activity each week

Fitness benefits and advice for Elderly

Physical benefits include:

• Preserving of bone mass

• Maintaining of aerobic fitness, including maximal oxygen uptake and muscular endurance

• Improved balance, coordination, muscular strength and flexibility

Mental benefits:

• less cognitive decline

• lower risk of dementia and alzheimers

• Enlarges gray matter and hippocampus

Menopause characteristics

• Occurs between ages 45 and 55

• Involved reduced estrogen and progesterone

• Risks include:

  • sarcopenia

  • osteoporosis

  • fractures

  • falls

  • increased abdominal fat

  • metabolic syndrom

  • type 2 diabetes

  • heart disease

• Symptoms include

  • hot flashes

  • mood changes

How can training impact menopause?

Resistance training helps increase muscle mass and strength, also helps preserve bone mineral density, especially at hips and femurs.

Aerobic excercise can reduce body fat and waist circumference

Regular exercise also improve mood, reduce insomnia and help prevent depression

What is oxygen deficit and how does it work?

1. At the start of exercise, oxygen demand rises faster than oxygen supply

2. A mismatch happens and body enters oxygen deficit

3. In this early stage body becomes reliant in anaerobic energy system

4. Stored ATP and Creatine Phosphate help meet energy demand until aerobic supply catches up

what is EPOC, the fast and slow component?

Elevated oxygen consumption above resting levels after exercise.

Fast component:

starts as soon as excercise stops and lasts 3 to 5 minutes after exercise. Its job is to:

• Resore ATP

• Replenish phosphocreatine stores

• Re-saturates myoglobin with oxygen

It looks like an increased rate of ventilation, and high HR

Slow component:

• Begins after, about 3 to 5 mins

• Can last several hours

• Purpose:

  • Oxidation( lactate —> glucose)

  • Removal of waste products (lactate + hydrogen ions)

  • Replenishment of energy stores such as protein, glycogen and triacylglycerol

  • Bring body closer normal state so drop in HR but still elevated (metabolism aswell)

  • cooling

  • Repair muscle inflammation to DOMS

Factors affecting epoc

1. Intensity of exercise

2. Intermittent nature of sport

3. Duration of exercise

4. Build up of waste products

5. Fitness level

6. Environmental factors

7. Body temp

Key idea- The greater the intensity, the greater the epoc

Epoc in untrained vs trained athletes

Trained has the following benefits:

• Recover faster, and more efficiently

• Incurs lower oxygen debt

• HR returns to resting levels faster

• Quicker replenishment of stores of PC stores

• Efficient removal of waste products

• Glycogen restoration is more efficient

Why does breathing rate remain high after sprinting? (epoc)

Early exercise creates an oxygen deficit because aerobic supply < demand, thus the anaerobic work is done, and oxygen is needed to pay back debt. This looks like the replenishment of:

• ATP stores

• PC stores

• Myoglobin oxygen stores

Fast vs slow component EPOC

Fast component- Responsible for paying back oxygen deficit, restore systems like ATP and Pc

Slow component- Main role is to remove waste products (oxidize lactate into glucose) restore other energy stores, and cool body down, help muscle recovery. Replenish fuel stores aswell

Difference between fatigue and exhaustion

Fatigue- Is the inability to continue exercising at the same or desired intensity

Exhaustion- The complete inability to continue exercising at all

Peripheral vs Central fatigue

Peripheral- Caused by factors outside CNS:

• Develops rapidly

• Caused by reduced muscle cell force

• Seen in short term high intensity activity

Central- Caused by factors within CNS like brain and spinal cord:

• Happens during prolonged exercise

• Caused due to impaired CNS

• More likely during long duration lower intensity excercise

• Is linked to motivation and reduced neural drive

What happens when ATP and Pc fuels are depleted?

They are immediate energy sources for muscle contraction but have limited stores. When depleted, muscle contractions weaken, and fatigue occurs.

It takes 15-20 seconds for phosphocreatine to be fully depleted at maximum intensity

What happens when glycogen fuels are depleted?

Endurance exercises rely heavily on carbs, and as exercise continues stores in liver and muscle become used up. Once glycogen stores are very low body becomes reliant on fat metabolism. This results in a performance drop as fat is less efficient for rapid energy.

Glycogen is used in glycolysis and Krebs cycle so it support almost all excercise intensities.

It can be used um in minutes or several hours depending on excercise intensity, and its restoration takes hours or days.

Blood glucose impact on CNS

CNS is reliant on blood glucose to function.

Low brain glucose = central fatigue

Good blood glucose supports muscle for production and neuromuscular drive

Example in marathons:

• A marathon runner wants to avoid fatigue

• Therefore they maximise glycogen stores before the race through carbohydrate loading

• During the race, they also consume carbs to spare glycogen and reduce hypoglycemia

How does dehydration cause fatigue?

• Increased sweat loss = reduced blood plasma = cardiovascular drift = high HR = impaired performance and earlier fatigue

• Reduced thermoregulation due to restricted skin blood flow = limited heat loss through evaporation = body temp rises causing fatigue

• Speeds up glycogen breakdown and increases liver glucose production = earlier glycogen depletion

• Also causes increased perceived exertion and impairs cognitive function

Common causes of hyperthermia

• Exercise in heat or humid conditions

• Insufficient air flow

• excessive clothing

• Lack of shade

How does hyperthermia cause fatigue?

Warm skin reduces temperature gradient needed to transfer heat from core to skin + Inability to lose heat via evaporation in humid conditions = rise in core temp

Fatigue is driven by central factors so with reduced brain blood flow there is an increase in perceived exertion causing athlete to slow down voluntarily

What is metabolic acidosis?

Metabolic acidosis is a reduction in normal pH in a fluid or tissue caused by acidic substances

Lactate vs lactic acid

Energy metabolism = lactate NOT lactic acid however lactate is not directly responsible for fatigue. Hydrogen ions produced during metabolism make blood and muscle more acidic.

Lactate can actually help reduce acidosis and serves as a crucial fuel during and after excercise.

How do waste products like hydrogen ions influence fatigue?

1. High intensity excercise causes release of hydrogen ions

2. Hydrogen ions reduce the sensitivity of actin and myosin

3. This means more calcium is needed for optimal muscle contractions

4. Disruption to calcium release impairs muscle contraction resulting in fatigue

Roles of sodium and potassium?

• They are electrolytes that conduct electricity in a solution

• Sodium is mainly outside of cells

• Potassium is mainly inside of cells

• Both regulate water and fluid movement across membranes by osmosis

Sodiums influence on fatigue

hyponatremia - Low plasma sodium concentration

It is mainly caused by over drinking hypotonic fluids such as water and is common in endurance events. Severe hyponatremia can cause brain swelling, seizures and death.

Potassium influence on fatigue

Both sodium and potassium are essential for transmitting action potential along motor neurons and into muscle

1. Intense exercise causes potassium to accumulate outside muscle cells

2. This reduces the concentration gradient and muscle membrane excitability.

3. Greater neural drive is needed to produce action potentials

4. Force production capacity falls, contributing to fatigue

How Inorganic phosphate causes fatigue?

1. High energy demand increases ATP and PCr breakdown, causing Pi accumulation

2. Pi reduces force production by interfering with actin-myosin force generation

3. It also reduces calcium sensitivity

4. This causes an impairment of calcium release the sarcoplasmic reticulum.

5. Results in a less effective muscle contraction and more prone to fatigue

CNS drive changes due to fatigue

1. Extracellular acidosis during high intensity exercise can reduce oxygen delivery brain increasing perception of effort

2. It also stimulates sensory neurons that signal distress

3. The brain therefore reduces neural drive to muscles to reduce metabolic demand causing central fatigue

What 3 categories are can signs of recovery be classified in

Physiological

Psychological

Symptomatic

Difference between physiological, psychological and symptomatic signs of recovery

Physiological :

• Internal measurable changes

Psychological:

• Mental/ emotional readiness changes

Symptomatic:

• The subjective feelings athletes report

Physiological signs of recovery

• Lactate levels decrease and are converted back into pyruvate or used for fuel

• Increase in pH due to the buffering of metabolic acidosis (is reduced) and removal of H^- ions

• Decrease in breathing rate as metabolic demand returns to rest

• Resynthesizing of energy stores

• Buffering- The neutralizing of hydrogen ions through the use of compounds (ie bicarbonate) to prevent sever pH drop

• Thermoregulation improves

Psychological sings of recovery

• Improved preparedness = mentally ready and motivated = CNS is ready to return

• Relief indicating a drop in anxiety

• Sense of achievement = gives satisfaction

Symptomatic signs of recovery

• Reduced muscles soreness = DOMS, repair and inflammation processes have finished

• Reduce nausea = gastrointestinal recovery after stress

• Restored appetite = nutrient replacement

• Normal sleep

Why are water and hypertonic drinks nutritional strategies for recovery

Water:

• Replaces fluids lost in sweat

• Transports nutrients

• Helps with temp regulation

Hypertonic drinks:

• Drinks with high conc of carbs for glycogen restoration after excercise

• NOT GOOD for immediate rehydration as their high solute conc slows water absorption (sugary drinks pull water form bloodstream into gut to dilute it

• Thus hypertonic is less effective then isotonic or hypotonic drinks for rapid rehydration
  

Why are carbs and protein nutritional strategies for recovery

Carbs:

• Maximises glycogen resynthesis

  • Athletes should consume high glycemic index carbs immediately after excercise

  • Within 2 hours

• 8-10g of carbs per kg of body mass per day

Protein:

• 20g of animal based protein straight after excercise maximises muscle protein synthesis

• Helps achieve positive net balance between protein synthesis and protein breakdown

Why are creatine and polyphenol rich foods nutritional strategies for recovery?

Creatine

• Increases muscle creatine stores

• Improves excercise performance = more explosive training

• Enhances training adaptations

Polyphenol-rich foods

• Plant based compounds found in fruits and veggies

• Have antioxidants and anti inflammatory properties

• Help maintain cellular health

• Reduce inflammation and oxidative stress

Most important supplements for recovery

1. Water

2. Carbs

3. Protein

4. Polyphenol-rich foods

5. Creatine

6. Hypertonic drinks

Physiological methods of recovery

• Cryotherapy

• Cryo cuffs

• Cooling jackets

• Cold water or ice immersion

• Cryo-chambers

• massage

• foam rolling

• compression

• Whole body vibration

Psychological and social methods of recovery

Psychological:

• Progressive muscle relaxation

• Imagery

• Autogenic training

• music

• Breathing exercises

Social:

• Group therapy

• Support from specialists

What is active recovery and its purpose?

Low intensity submaximal exercise done after a fatiguing effort, as a cool down or on rest days

Light aerobic exercise = 40% VO2 max

Moderate exercise = 40-60% of VO2 max

Main goal is to preserve performance by accelerating recovery (reduces DOMS and EIMD, exercise induced muscle damage

Lowers blood lactate faster, clears metabolites and restores pH and homeostasis

Most used during maximal efforts that must be repeated within short time

How does stretching help recover?

Passive stretching lengthens the muscle tendon unit without voluntary contraction and includes static and cyclic forms

What is myofascial release?

• Self massage using foam rollers

• Applies pressure to soft tissue using bod weight or upper body strength

• Can increase short term flexibility, joint ROM and reduce DOMS

How do compression garments achieve their purpose?

They apply mechanical pressure through items like socks and sleeves

Result in:

• Reduces perceived muscle soreness, extra support, analgesic effect

• May also increase venous return, increase SV but more research is needed

Features of cryotherapy and benefits and limitations

Things like contrast therapy alternate hot and cold to create a vascular pumping effect.

Leads to:

• rapid vasoconstriction

• Pain relief through slowed nerve signaling

• Accelerated repair through improved flushing of oxygen/nutrients and waste removal

Limitations include:

• Injury risk is used incorrectly

• Limited long term evidence

• Requires proper use
  

Sleep for recovery

Critical for recovery as it helps reduce muscle soreness

Sleep loss can reduce alertness, slow reaction time and attentional capacity

Melatonin is secreted in response to darkness and suppressed by light.

Melatonin also causes peripheral vasodilation helping lowering core temp for sleep

Circadian rhythms affect performance with peak for aerobic performance being from 4:30-6:30 pm.

Evening chronotype people perform worse when forced to train off schedule, but competition motivation and arousal can partly override time of day disadvantages

What is jet lag and its impact on performance

The desynchronization between the internal circadian rhythm and destination time that occurs when crossing 3 or more timezones. It is worse when travelling eastword as the day gets shorter.

It can cause:

• daytime exhaustion

• sleep disruption

• gastrointestinal issues

To reduce jet lag athletes should use zeitgebers, especially local light dark cycle.

Inhaling and exhaling mechanics

During inspiration when the air goes in, the diaphragm contracts and flattens. External Intercostal muscles contract to push the ribcage upwards and outwards. The thoracic volume increases which leads to the thoracic pressure to decrease (air fills the cavity allowing more space to be used, therefore decreasing pressure). The air moves from high to low pressure (in the lungs). Accessory muscles assist the body with inspiration during exercise such as the Trapezius, Scaleni, Sternocleidomastoids. 

During expiration the diaphragm relaxes and is pushed upwards. The external intercostal muscles contract. The thoracic volume decreases and therefore the thoracic pressure increases. This results in the air from high to low pressure out of the lungs. Accessory muscles contract like the abdominal muscles.