You can customize BACK to function as a lap key during timed activities. Select START, and select an activity profile. Select Options > Laps > Lap Key. The lap key stays on for the selected activity profile until you turn off the lap key.. With the garmin coaches there often is a "until lap pressed" step between the warmup and the intervalls. You absolutely have to press the lap button to continue the workout. It just gives you time to look at the next steps.
You can turn on the Lap Key setting to record a lap or a rest during an activity using BACK. You can turn off the Lap Key setting to avoid recording laps due to accidental key presses during an activity. Hold MENU. Select Settings > Activities & Apps. Select an activity. Select the activity settings. Select Lap Key.. New to Garmin Coach and selected a training plan. On the next workout it schedules: 10 min warm up. Lap Button Press. 6 x Run then jog. 10 min cool down. Never used the lap button before so looked up the guidance for my vívoactive 3.