Is Your Garmin Coach Plan Too Hard? How to Tell, and What to Change

How Garmin Coach sets your plan

There are two kinds of plan. The coach-led plans, from Jeff Galloway, Greg McMillan and Amy Parkerson-Mitchell, cover the 5K, 10K and half marathon, and Garmin says the only difference between the coaches is their method.¹ Garmin Run Coach builds a plan from an end date or goal and the days you want to train, and adjusts it using your watch's data, such as VO2 max, lactate threshold and training history.²

For the coach-led plans, Garmin's setup asks how many miles you run in a week, with an option for not running yet, then your average running pace, then whether you want a time goal. Garmin's own advice at the first question is to be honest.¹

Your time goal sets the paces of your runs. Runners answering on Garmin's forum put it plainly: change the goal and the paces change with it.³ Run Coach also reads your sleep, stress and recovery, so Garmin asks you to wear the watch as much as you can, overnight included.⁴

What runners report

The reports we read on Garmin's forum share a pattern: paces set from a goal faster than the runner's fitness that day, or a load that climbed faster than the runner's legs. Most of the trouble showed up early in the plan.

• A runner on a 5K plan (December 2019) said the paces were too fast, their easy runs registered as tempo runs, and they could find no way to bring the paces down.³
• A runner on a Galloway 10K plan (September 2019) was due to run 18 repeats of 800 metres, over two hours of repeats, while the long run grew by 4 km a week to 24 km. The accepted answer, after the question was put to Galloway, was that this is how the plan was designed.⁵
• A runner on a Greg McMillan half marathon plan (November 2023) found their watch rating every easy run as a threshold or VO2 max run. Another runner replied that the goal had them training at future fitness, and suggested an easier target for the first four to six weeks.⁶
• On Run Coach (July 2025), a runner whose usual run was 5 km was set an 81 minute run, an extreme ramp-up in their words, and another who chose seven running days got hard runs back to back for the first two weeks.⁷
• A runner on a 5K plan (February 2020) moved one run, and the reshuffle turned a 3 mile steady run into 5 miles and added 5 miles of intervals.⁸

How a coach tells whether your plan is too hard

A coach never judges a plan on its own. They read it against the running you do now. These checks catch most plans that start above the runner:

1. Week one against your last four weeks. If the first week asks for clearly more running than you have averaged lately, the plan starts above you. More in the base building guide.
2. The first long run against your longest recent run. A long run well past anything you have run in the last month is a jump, not a step. The long runs guide explains how they build.
3. The number of hard sessions. Count the runs with repeats, tempo or goal pace. The less you were running before, the fewer of these your legs are ready for. The easy and hard mix guide covers the balance.
4. How the easy runs feel. Easy running should be conversational. If your heart rate on an easy run sits well above your easy zone, the paces were set from a goal faster than your fitness today. The heart rate zones guide explains the zones.
5. How you feel across weeks two to six. Tiredness that builds week on week, or an ache still there on the next run, is the plan telling you it is ahead of you.

What to change in Garmin Coach

Garmin's own pages say little about changing a plan once it starts, so these come from runners on Garmin's forum:

• Set a slower time goal. The paces follow it, though runners say workouts already on your calendar can take about a week to change.³ One runner found a changed goal would not save.⁹ If yours will not, start a new plan and give the setup your usual week and your usual pace.
• On Run Coach, one runner switched off the setting that includes strength workouts to take those extra sessions out of the plan.⁷ Choosing fewer running days does the same for the runs.
• After you move a run, read the rest of the week again before you run it. A reshuffle can hand you longer or harder runs than the ones you had.⁸

What if it feels too easy?

Runners report this too. One was halfway through week 7 of a 13 week half marathon plan with nothing but easy runs.¹⁰ Another told the setup they ran 40 km a week and was given 12 km of easy running to start.¹¹ Easy days that feel easy are the plan working. But a first week far below what you already run, or no harder session by the middle of a plan, means the setup did not read you. A coach starts you close to the running you already do, and builds from there.