I'm not sure what you mean by "accuracy", but it does put down more points as you're moving. As a result, it will look more smooth. A simple calculation/conversion (0.01km/s -> 36km/h) shows that you will be putting down a single point every second only if you're traveling 36km/h or faster. If you set the logging distance to 0.00km, then theoretically it will log points every second as long as you're moving at a speed the GPS can detect.

Take a look at osm.wiki/Garmin/eTrex_Vista_HCx#Recording_traces -- your log, using 0.00km, will be the same as the green line, except it won't log unnecessary points while your detected speed is 0.