Metabolic demands Flashcards
(40 cards)
Define kinematics and kinetics in the context of mechanical needs analysis.
- Kinematics refers to joint positions and motions (e.g., hip abduction, shoulder circumduction).
- Kinetics refers to the muscle groups and how they are contracting (e.g., concentric knee extensors or quads)
How do kinematics and kinetics relate to describing and explaining movement?
Kinematics describes “what am I looking at?” while kinetics explains “how is it happening? When? Which muscle?”.
Define steady state activity and its primary energy system.
A steady state activity is sustained by predominantly aerobic metabolism. It is usually longer in duration, lasting more than a few minutes.
What are the three main bioenergetic systems?
◦ Adenosine triphosphate phosphocreatine system
◦ Glycolytic system
◦ Aerobic system (Krebs cycle and electron transport chain, or oxidative phosphorylation)
Define non-steady state activity and give examples.
Non-steady state sports involve a constant fluctuation of intensity. Examples include team games like hockey, basketball, field hockey, rugby, and lacrosse. These sports require both aerobic metabolism and bouts of moderate to high intensity
What are the limitations to performance?
- oxygen delivery to working muscles
- oxygen extraction by working muscles
- Oxygen utilization by working muscles
- substrate availability
limitations can be mechanical and metabolic
What are the limitations of steady state activities?
◦ Central mechanisms (ability to intake and transport oxygen)
◦ Peripheral endurance (ability to extract and utilize oxygen)
◦ Substrate availability (primarily carbohydrates)
Explain the Fick equation and its components.
The Fick equation states that VO2 (aerobic power) is determined by cardiac output and arterial-venous oxygen difference (AVO2 difference). Cardiac output is a central factor, while AVO2 difference is a peripheral factor.
- VO2 = Cardiac Output x AVO2 difference
How is cardiac output calculated?
Cardiac output is calculated by multiplying heart rate by stroke volume
What factors determine maximum heart rate, and how is it affected by training?
Maximum heart rate is primarily determined by age and genetics. It doesn’t change much through training
What is stroke volume and how does it change with training?
Stroke volume is the amount of oxygenated blood leaving the heart with each beat. It can be increased through training by increasing the left ventricular chamber size and strength. However, there are physiological limits to how much the heart can enlarge
What happens to VO2 max after a few years of training?
VO2 max typically peaks after a few years of training. After cardiac output plateaus, further improvements in VO2 max are primarily due to peripheral factors, such as the muscles’ ability to extract and utilize oxygen efficiently
How do you administer a VO2 max test, and what principle should you adhere to?
VO2 max tests are incremental tests, commonly done on a treadmill or bicycle. It’s important to follow the specificity principle, meaning the test should be specific to the person’s sport or activity. For example, runners should be tested on a treadmill, not a bicycle
What criteria are used to determine if a VO2 max test is credible or valid?
◦Volitional exhaustion: The person stops the test because they cannot continue.
◦ Plateau in VO2 uptake
◦ High blood lactate levels: exceeding some threshold such as 6 or 7 millimole.
◦ Respiratory exchange ratio (RER) above 1.0
◦ Achievement of estimated max heart rate
◦ High Rating of Perceived Exertion (RPE)
What is a typical VO2 max range for a healthy adult?
A typical VO2 max range for an active, healthy adult is 30-60 mL/kg/min
Besides VO2 max, what other metabolic parameter is important?
Anaerobic threshold is a critical metabolic parameter.
Why is anaerobic threshold important?
Knowing the anaerobic threshold is important because:
◦ VO2 max occurs at an intensity greater than anaerobic threshold.
◦ It indicates the percentage of VO2 max that can be maintained with mostly aerobic metabolism.
◦ Knowing the intensity at which it occurs is valuable for training and racing.
What is the approximate anaerobic threshold for an average untrained individual?
An average untrained, active, healthy adult reaches their anaerobic threshold at around 50% of their VO2 max. For metabolically demanding, non-steady state sports, it’s around 75% of VO2 max. Elite endurance athletes can reach even higher percentages
How can an athlete improve performance if their VO2 max has plateaued?
If VO2 max has plateaued, an athlete can still improve performance by increasing the intensity at their anaerobic threshold.
How can you measure and use anaerobic threshold to prescribe training?
Anaerobic threshold can be measured through lactate measurements. The goal is to find the “sweet spot” where lactate is high but plateaus, indicating the athlete is just under their anaerobic threshold. This helps determine the pace for steady state
How can an athlete improve their anaerobic threshold?
◦ Increase VO2 max capabilities.
◦ Improve the intensity or relative percentage of VO2 max that can be sustained during steady-state exercise. Train above anaerobic threshold using high-intensity interval training or sprint training
What are the three major factors that influence pace in endurance events?
◦ VO2 max
◦ Intensity at anaerobic threshold
◦ Technique
Define repetitive and non-repetitive activities from a metabolic perspective in non-steady state sports.
◦ Repetitive: The work-rest cycle is repeated. Examples include team sports like hockey and soccer.
◦ Non-Repetitive: Work occurs for the entire event without significant rest periods. Examples include short races.
What is the most important metabolic parameter for non-repetitive, non-steady state performance?
The intensity that can be performed is the most important metabolic parameter.
