Glossary

Every word this app uses, in plain English. If a chart confuses you, the word is here.

B D E F H I L P R S T W Z

B

Bounce compared with step length— also called vertical ratio: Your up and down movement as a share of how far each step takes you. Bounce and step length judged together instead of separately. See it on Running Form

D

Daily effort: A score for how hard each day of training was. The training stress of each day. See it on Load and Recovery

E

Easy run: A run slow enough that you could hold a conversation the whole way. Most of your running should be like this. See it on Load & Recovery
Effort against heart rate: Each dot is one run: the watts (W) you made and the heart rate it cost. Your average effort in watts next to your average heart rate for the same run. See it on Efficiency
Effort against speed: Whether the watts (W) recorded match the speed you were running. Your average effort next to your average speed for every run with both. See it on Data Quality
Effort spent holding form— also called form power: The watts (W) you spend bouncing and braking rather than moving ahead. The part of your effort that does not push you forward. See it on Running Form
Effort spent pushing air— also called air power: The watts (W) used to push through the air. The cost of air resistance during the run. See it on Running Form

F

Fade— also called aerobic decoupling: Does your heart work harder in the second half of a long run? We split each long steady run in half. We check whether your heart rate climbed in the second half while your effort stayed the same. See it on Marathon Core
Fitness score— also called VO2max: A general fitness score calculated by Tredict. Roughly how much oxygen your body can use when working hard. See it on Efficiency
Foot contact time— also called ground contact time: How long your foot stays on the ground, in thousandths of a second. How long each foot is touching the ground. See it on Running Form

H

Heart rate variability— also called HRV: How recovered your body is, measured while you sleep. The small changes in time between your heartbeats overnight. See it on Load and Recovery
How much you bounce— also called vertical oscillation: How far your body moves up and down with each step, in centimetres (cm). The height your body rises and falls on every step. See it on Running Form

I

Interval session: A run made of hard efforts with easier recovery parts between them, instead of one steady effort. See it on Efficiency

L

Left-right balance— also called ground contact time balance: Whether your left and right legs spend the same time on the ground. Whether one leg is working harder than the other. See it on Running Form
Leg springiness— also called leg spring stiffness: How much your legs behave like springs, in kilonewtons per metre (kN/m). How well your legs store and return energy on each step. See it on Running Form
Longest run: The time of your single longest run each week. How long you can keep running without stopping. See it on Marathon Core

P

Power for each heartbeat— also called power aerobic factor: How many watts (W) you produce for each beat of your heart. The effort you make for the heart rate you pay for it. See it on Efficiency

R

Recent load and usual load— also called acute and chronic load: Your training in the last 7 days compared with your normal amount. Whether this week is heavier or lighter than you are used to. See it on Load and Recovery
Resting heart rate: Your heart rate when fully at rest. How slowly your heart beats when you are doing nothing. See it on Load and Recovery
Runs with effort recorded: One bar per run, oldest on the left, showing whether effort in watts (W) was saved. Which runs have usable effort data and which do not. See it on Data Quality

S

Sleep: How much you slept, compared with your normal amount. Your sleep each night. See it on Load and Recovery
Speed compared with your own best— also called speed index: How fast this run was compared with what you are capable of. A score by Tredict for how fast you ran relative to your own capacity that day. See it on Efficiency
Speed for each heartbeat— also called speed aerobic factor: How much speed you get for the heart rate you are paying. Your speed compared with how hard your heart is working. See it on Efficiency
Speed from your stride against recorded speed: Your step length times your steps per minute, next to the speed in the file. Two independent ways of working out the same speed, side by side. See it on Data Quality
Speed per watt— also called running effectiveness: How much speed you get from each watt (W) of effort. How efficiently you turn effort into forward movement. See it on Efficiency
Steadiness— also called variability index: How constant your effort was during a run. Whether the run was steady or had hard and easy parts. See it on Efficiency
Step length— also called stride length: How far you travel with each step. The distance covered by one step. See it on Running Form
Steps per minute— also called cadence: How many steps you take in one minute (spm). How quickly your feet turn over. See it on Running Form
Steps per minute versus speed: Your steps per minute (spm) at each running speed. Steps per minute judged against the speed you were running. See it on Running Form

T

Threshold power— also called Critical Power: The effort in watts (W) you can hold for about an hour. Roughly how strong your engine is, measured in watts (W). See it on Marathon Core
Time in the air— also called flight time: How long both feet are off the ground, in milliseconds (ms). The airborne part of each stride. See it on Running Form
Training balance— also called acute to chronic workload ratio: This week's training divided by your normal amount. A single number for whether you are doing about the right amount. See it on Load and Recovery

W

Wasted effort— also called form power factor: The share of your effort that does not push you forward. Energy spent bouncing and braking instead of moving ahead. See it on Efficiency
Watt (W): The unit of effort your Stryd footpod measures. More watts means you are pushing harder, whatever the treadmill says. See it on Marathon Core
Weekly training minutes: How many minutes you ran each week. The total time you spent running in each week. See it on Marathon Core

Z

Zone: A band of heart rate or effort. Zone 1 and 2 are easy, Zone 3 is moderate, Zone 4 and 5 are hard. See it on Load & Recovery