Traditional Pace Time
The more traditional masters swimming approach sees a set number of lengths for each element of the workout, with the volume varying by lane since each lane will be at a slightly different pace. Each section will be based on a 'On' time. This means the lead swimmer will depart every _ seconds so the active and rest are combined. For example, you may be asked to do 50m intervals on 90 seconds. That means the lead out departs every 90 seconds. If you finish after 60 seconds, that means you have 30 seconds of rest.
Early Season Sample (fast lane):
Timed Segment Approach
This is a simplified approach in which the group does the prescribed set for a certain duration of time. This allows each lane to be active for the same length of time, the faster swimmers simply completing more metres. This approach also utilizes perceived exertion instead of pace times while still designating a timed rest interval.
Early Season Sample: