KIN320 Lec 17 - Metabolic Equations

High Effort, Short Duration:
- Energy used needs to be paid back; energy return is delayed.
- Key concept: There's an inherent cost of energy in performing any work.

Definitions:
- Work: Displacing a force over a distance.
- Formula: Work = Force × Distance
- Energy: Capacity to do work.
- Same units as work; raising an object converts potential energy into work.
- Power: Rate at which work is performed.

Focus on biomechanics in the study of work, energy, and power related to exercise physiology.
V O2 Tests:
- Typically performed on a treadmill with incline.
- Why incline?: Running on a flat surface does less work against gravity. An incline allows for the measurement of external work.
- Treadmill incline calculations account for work against gravitational force.
- Different procedures and parameters for calculating work in cycling versus running.

External Work: Measurable energy exerted against gravitational force.
Internal Work: Energy utilized in bodily movements that don't translate into measurable external work (e.g., moving limbs).
Calculations for metabolic costs can be derived from v O2 tests under controlled conditions.

Human Efficiency: Generally low in converting energy into external work (3-5% efficiency in typical tasks).
- Energy loss primarily manifests as heat dissipation (energy sinks).
- Example: Cycling has higher efficiency than running because more energy is utilized for propulsion rather than dissipating heat.

Efficiency Formula:
- Efficiency = External Work / Energy Expenditure
Use of efficiency definitions may lead to threshold value discussions.
- Link to biomechanical modeling, Snook tables, and NIOSH standards.

Typically, indirect heart rate measurements have around 20% error margin.
Thresholds:
- Findings indicate around 16 kilocalories per minute as the maximum V O2 for healthy males.
- Revising from 50% of maximum power standing to 33% as a sustainable threshold based on injury risks.

NIOSH Energy Standards:
- Identify maximum sustainable workloads based on metabolic demand and capacity limitations.
- Discussion on adapting work conditions to fit rest and recovery protocols within standard working hours.

Work Analysis: Assessing lifting capacity based on metabolic cost to avoid fatigue over working hours.
Understanding physical fitness varies among individuals and may alter their work capacity on tasks.
Importance of frequency, body position, and worker characteristics when applying metabolic equations.

Example: Calculating work done when lifting a load.
- Constants involved in calculations include body weight, distance moved, frequency of lifts, etc.
- Discussed detailed equations for squat lifts vs. stoop lifts focusing on muscle groups utilized and biomechanics.

Work measurements need continuous adaptation based on individual physiology and task requirements.
Consideration for shifts between external versus internal measures and how they fundamentally change workload calculations.
Efficiency should always be considered in light of real-world applicability to limit injury risks and maximize endurance in work tasks.

Emphasis on exploring the validation of metabolic equations with larger and diverse subject groups for anthropometric considerations.
Need for ongoing development of models that can respond more robustly to the dynamics of labor and workload without relying solely on averages or assumptions may enhance occupational safety practices.