Each activity has a value for every column present across all activities, with NAs populating missing values.
For the types argument, the default is type = NULL which will retrieve all available stream types. The available stream types can be any of time, latlng, distance, altitude, velocity_smooth, heartrate, cadence, watts, temp, moving, or grade_smooth. To retrieve only a subset of the types, pass a list argument with the appropriate character strings to type, e.g., type = list("time", "latlng", "distance").
Invalid HTTP requests (404 or 400 code) may sometimes occur for activities with incomplete data, e.g., stationary activities with no distance information. In such cases, changing the `series_type` and `resolution` arguments may be needed, e.g., `series_type = "time"` and `resolution = "medium"`.