Week 1 Flashcards
(21 cards)
Types of research and their definitions?
Basic Research - systematic study of fundamental topics in biology
Translational Research - ‘bench-to-bedside’ application of research findings
Applied Research - Studies designed to solve practical problems (evidence- based practice)
What is homeostasis and why is it important in physiology?
A core concept in physiology and a fundamental principle of body function.
Refers to the maintenance of a constant internal environment.
Physiological variables must stay within a narrow range of values.
Balance between variables is essential—homeostasis of one variable depends on others.
What is Steady State? Examples?
Where a physiological variable remains constant and stable but not necessarily at a “normal” level, as may differ from resting/ideal values
Reflects a balance/equilibrium between the demands placed on the body and the body’s response to those demands.
Examples: Heart rate, body temperature, arterial blood pressure.
Physiological Feedback Systems?
- Negative Feedback
Reverses a change to restore homeostasis
Example: Regulation of CO₂ levels in blood
- Positive Feedback
Enhances or amplifies the original stimulus
Example: Childbirth (oxytocin release intensifies contractions)
- Gain
Describes the sensitivity or strength of the control system
Higher gain = more effective at maintaining homeostasis
What is fitness testing used for? affected by?
Fitness testing in sport forms a vital piece of analysis that is key for success, allowing analysis of progress, information extraction (eg for rehab) and development of tech
Those in fitness need to understand, interpret and prescribes activities based on the individuals
Factors effecting:
- Genetics
- Training history
- Motvation
- Lifestyle
Categories of physical fitness?
Cardiorespiratory Capacity: Aerobic capacity (VO2max).
Body Composition
Musculoskeletal Fitness: Flexibility, strength, endurance.
Skill-Related Fitness: Agility, balance, coordination, speed, power, reaction time.
Testing Loop?
A structured process to guide performance improvement:
Benchmarking – Assess current fitness characteristics.
Testing – Conduct standardized tests (e.g., VO₂ max, strength).
Analysis – Interpret test data to identify strengths and weaknesses.
Feedback – Provide actionable insights to the athlete/coach.
Training Adjustment – Modify program based on results to improve outcomes.
What is VO2max (Testing) and types of tests?
Cardiorespiratory Fitness: Interaction between the heart and lungs that maximise performance and recovery. Their CR endurance is the ability to perform strenuous task for a prolonged period
The maximal rate of oxygen consumed defines the cardiorespiratory power and is also known as VO2max/peak
- Types of Tests:
- Population norm-based tests eg beep or step test.
- Submaximal prediction tests eg treadmill walking (often in older or clinical populations)
- Direct VO2max measurement based off max oxygen consumption (Vo2 max L/min) at near or to exhaustion
Higher = greater ability to sustain aerobic work.
Laboratory vs. Field-Based Testing?Needs?
Controlled laboratory conditions can provide ideal settings to determine Vo2max but requires equipment, expertise/experience, and single participants at a time which is time consuming
Field based testing is better for team situations eg the bleep test however is more of a prediction than measure based on indirect measures
Needs:
- Reliability: will the score be the same if done twice
- Validity: Are they accurate, does it fit gold standards
- Modality: What equipment eg treadmill, bike, swimming flume based on upper or lower body sports
- Consideration: Who is being tested, athlete, general population or clinical population, what are the risk and do they differ between groups.
Trade-offs in accuracy, equipment needs, and practicality.
Verification of VO2max?
Key verification methods include:
A plateau in O2 consumption despite increased work rate - gold standard verification
If gold standard not achieved you can verify by:
- Did they reach Age predicted Heart rate (+/- 10bpm)
- Blood lactate concentration of 8mmol or higher
- Respiratory exchange ratio (RER) of 1.15 or higher
- Verification test - Perfrom another exercise after recovery at higher intensity than last stage of prior test to see if they can reach higher Vo2 max
VO2max in Population and Athletes?
Classified by gender (men typically higher due to higher ejection volume, haemoglobin conc and muscle mass) and declines with age, can be in either poor, fair, average, good or excellent.
Elite endurance athletes typically have high VO₂ max values, however isn’t as trainable as they have already maximised adaptations, this meaning they have less of a positive correlation between Vo2 max and endurance performance, and performance often improves independent of Vo2 max such as:
- Running economy
- Lactate threshold
- Anaerobic capacity
Examples (Male/Female):
CCS = Up to 96, 72-80ml/kg/min
Cyclists = 70-85, 60-75
Running = 65-85, 55-70
Football = 50-60, 45-55
However, performance improvements can also occur independently of VO₂ max, through:
* Better running economy
* Higher lactate threshold
* Anaerobic capacity
Homeostasis? Examples of Homeostatic control?
- One of the core concepts critical to understanding physiology and fundamental principle of body function. In short it is the Maintenance of a constant internal environment.
- All variables of physiological mechanisms must operate within a narrow range of values.
- Furthermore, there needs to be a balance between different variables. This means that homeostasis of one variable is not independent of other variables
Examples:
- Body temp regulation - thermal receptors send message to brain, skin blood vessels and sweat glands respond to regulate temp
- Regulation of blood glucose - insulin response triggered
- Regulation of cellular homeostasis - stress proteins repair damaged proteins to restore homeostasis in response to changes in temp, ph, free radicals.
Exercise is a major test for the bodies homeostatic ability.
Steady State? Examples?
Definition: A physiological condition where a variable remains relatively constant, though not necessarily at resting (baseline) levels.
- Reflects a balance between demand and response during sustained activity.
Key Features:
- Variable is unchanging over time.
- Does not mean ‘normal’—just stable under current conditions.
Examples:
- Heart rate during prolonged submaximal exercise
- Body temperature during moderate intensity work in temperate conditions
- Arterial blood pressure during sustained activity
Physiological Feedback Systems?
Negative Feedback: Reverses changes to maintain homeostasis (e.g., CO2 regulation in extracellular fluid) - Most control systems work via negative feedback, to return to set point providing stability.
Positive Feedback: Enhances the original stimulus, accelerating to completion (e.g., childbirth).
Gain: Degree to which control systems maintains homeostasis - Sensitivity of the response system (eg pulmonary and circulatory systems have large gain)
Biological Control Systems? Components? Examples?
Intracellular Regulation:
- Protein synthesis and breakdown
- Energy production
- Maintenance of nutrient stores
Organ System Regulation:
- Pulmonary and circulatory systems
- → Replenish O₂ and remove CO₂
Core Components of Control Systems:
- Sensor (Receptor): Detects change
- Control Center: Assesses input, sends signal
- Effector: Carries out response to restore balance
Examples:
- Pulmonary system
- Circulatory system
Adaptation and Acclimation?
Adaptation:
- Long-term structural/functional changes of cells or organ systems to improve ability to maintain homeostasis.
- Occurs more slowly
- Many adaptive changes occur within cells and are linked to genetic changes
Acclimation:
- Adaptation to environmental stresses (eg heat, hypoxia stress) resulting in improved function of existing homeostaic system
- Change in phenotype that is reversible and occurs rapidly
- Short-term
Exercise-Induced Hormesis?Outcome? Mechanism?Graph?
Definition: Low-to-moderate stress from exercise (e.g., chemical or environmental) triggers beneficial cellular adaptations.
Outcome: Enhances the body’s ability to maintain homeostasis.
Graph Representation: Optimal training load = upward performance progression.
Undertraining or overtraining = plateau or decline.
Mechanism: Adaptation occurs through cell signaling pathways (e.g., intracrine, paracrine communication) that mediate stress responses and recovery..
Cell signalling pathways?Role? Types?
Required to promote cellular changes
Involves:
- Communicating between cells using chemical messengers (CM)
- Cooridnates cellular activities
- Important for maintaining homeostasis
Five different cell signalling pathways exist inside cells:
1. Intracrine - CM inside cell triggers response
2. Juxtacrine - CM passed between two connected cells
3. Autocrine - CM acts on same cell
4. Paracrine - CMs act on nearby cells
5. Endocrine - CMs (that are hormones) release into blood which affect cells with specific receptors to these hormones
Velocity at vo2 max?
The speed at which Vo2 max is elicited, how fast are you running when you reach vo2 max
Stronger predictor of endurance running than vo2 max alone, particularly for middle distance running events at 95-120% vo2 max (800m-5km)
A combined measure of Vo2 max and running economy - the oxygen cost of running at a given speed (ml/kg/km)
Fractional utilisation of Vo2 max?Key determinant and Implication?
Definition: The percentage of VO₂max that can be sustained during prolonged exercise.
Importance:
- A high VO₂max is useful, but the ability to maintain a high % of it without fatigue is critical for performance.
Key Determinant:
Lactate Threshold:
- The highest intensity at which lactate production = lactate clearance.
- Beyond this, lactate accumulates and exercise becomes unsustainable.
Implication:
- Lactate threshold is a strong predictor of performance, especially in long-distance events.
Anaerobic capacity?
The ability to produce, tolerate and sustain max/supramaximal work rates through anaerobic energy production
