The songs in the stamina category aim to challenge the physical capabilities of the players through the length and speed of the songs. Stamina charts predominantly feature continuous streams with minimal tech or mods.
Since stamina and footspeed are all about how much stream you can do (and at what speed you can do it), players often communicate a chart's content with "breakdown notation". The stepartist may write breakdown notation and include it in the metadata of the chart. Additionally, some themes (like Simply Love) will generate breakdown notation and display it on top of the density graph on the song wheel.
Density graphs are a way to visually represent the contents of a chart. They show the density of arrows in a chart over time. The Y-axis is BPM and the X-axis is time. The scaling of both axis is to 100%, so to really understand the full context of a graph, you need to know the charts BPM and song length.
Some themes (like Simply Love), will generate these automatically in the song wheel. Otherwise, tools like Breakdown Buddy (see below) can generate these as well.
Stamina players often measure their progress with two numbers that represent the highest block pass they have obtained and the fastest bpm that they have completed 32 measures of stream on.
For the footspeed number the BPM and 32 measures of stream is normalize to 16th notes. Doing 64 measures of 8th notes, or 32 measures of 16th notes or 16 measures of 32nd notes would all satisfy the 32 measures requirement. For example both 64 measures of 8th notes at 180 BPM or 32 measure of 16th notes at 90 BPM would result in a footspeed number of 90.
Players in the Stamina Nation discord will often append these two numbers to their name in the form of (Footspeed Number|Maximum Block Pass).