Capacity indicators and efficiency indicators

Capacity indicators and efficiency indicators are benchmarks.

They allow you to:

• Identify trends in your efficiency and economy.
• Determine your current fitness level and use it to make predictions and zone adjustments.
• Compare yourself with other athletes.

Heart Rate Pace Factor

The Heart Rate Pace Factor is a capacity indicator and describes the relationship between the average heart rate intensity and the speed of the workout. 

The simplified formula for this is:

heartratePaceFactor = avgSpeed / (avgHeartrate / heartrateMax)

A higher value at the same speed thus indicates a better aerobic capacity.

In the relational diagram of the analysis you can follow up on whether your aerobic performance improves, or which workouts are most effective. Create a chart with the Heart Rate Pace Factor on one axis and the pace on the other axis. 

This value is suitable as a reliable and simple comparison parameter between athletes, as long as maximum heart rate has been correctly determined.

Heart Rate Power Factor

The Heart Rate Power Factor is a capacity indicator and describes the ratio of the average heart rate intensity and the normalized/perceived wattage of the workout. 

The simplified formula for this is:

heartratePowerFactor = normPower / (avgHeartrate / heartrateMax)

A higher value for the same power output thus indicates a better aerobic capacity, similar to the heart rate pace factor, but is more accurate in hilly terrain, for example.

Create a relation chart with Heart Rate Power Factor on one axis and Perceived Power on the other axis to find your best workouts. 

This value is related to the output value of your power meter and should be re-evaluated when changing the device.

Read the blog article on the factors: Visualize and recognize fatigue after a training session

Pace Power Index

The Pace Power Index is an efficiency indicator, or efficiency index, and describes the ratio of the average speed to the average wattage of the training. 

The simplified formula for this is:

pacePowerIndex = avgSpeed / avgPower

Higher values indicate a better conversion from power to speed.

Cyclists can use this value to compare the efficiency of different gear ratios. Runners can use it to compare the efficiency change of a repetitive training. 

In order to obtain an exact statement about changes in efficiency over time, similar conditions should prevail in the training sessions to be compared. 

This value is related to the output value of your power meter and should be re-evaluated when changing the device.

"Form Power" Index

The "Form Power" index describes the ratio of average power to the Stryd Form Power. 

The simplified formula for this is:

formPowerIndex = power / formPower

A higher value indicates a better efficiency of your training, since less power dissipation has occurred relative to the total power.

The "Form Power" index is directly comparable without further reference. 

This value is related to the output value of your power meter and should be re-evaluated when changing the device.

Running Effectiveness

Running Effectiveness is calculated as the ratio of running speed and specific running power and can be used to predict power and speed. 

The formula for this is:

RE = avgSpeed (m/s) / specificPower (W/kg)

Read the detailed blog article on running effectiveness: The Running Effectiveness (RE) metric in Tredict

VO2max

The calculated VO2max (Volume-Oxygen-Maximum) is a sports science figure that describes your aerobic fitness. 

It indicates the maximum amount of oxygen that can be absorbed by the body during a maximum load over a long period of time. The unit reads as millilitres of oxygen per minute and is abbreviated to ml/min. 

Ideally, this value is determined by respiratory gas analysis during maximum physical effort, but it can also be calculated with deterministic factors from heart rate capacity and speed, so that an approximate comparability is given. 

The simplified formula for this is:

VO2max = (avgSpeed / (avgHeartrate / heartrateMax)deterministicExponent)deterministicExponent 

Similar to the Heart Rate Pace Factor, a higher value indicates better cardiovascular fitness, i.e. you can complete speed units faster or complete very long units at a lower heart rate.

Due to the deterministic factors, this value is only calculated for running activities. However, for any sport you can use the Heart Rate Pace Factor, which is proportional to VO2max in running.

VO2max is directly comparable without any further reference. For a reliable value, the maximum heart rate must have been determined correctly.

Relative VO2max

The relative VO2max is based on the VO2max but includes body weight. 

This allows you to see how changes in your weight will affect your VO2max. 

For comparability with other athletes, this value is only somewhat suitable, since the ratio of muscle to fat and water is not included. The unit reads as millilitres of oxygen per minute per kilogram and is abbreviated as ml/min/kg.

Swimming Efficiency Index

The efficiency index for swimming is a SWOLF value normalized to a 50m length. 

So you can compare the value regardless of the length you have swum. 

Outdoor swimming activities can also be classified in this way. 

The SWOLF value describes the number of swim strokes per length plus the time taken. The formula for the Swimming Efficiency Index is:

efficiencyIndex = (strokes + duration) / (distance / 50)

A lower efficiency index is therefore better, as fewer swim strokes are required.

The swimming efficiency index is directly comparable without further reference.