Garmin Training Load Explained: Three Numbers, and the One Nobody Reads

There is a reason "Garmin training load" is confusing: it is not one number. Depending on your watch and the screen you are on, the word "load" is attached to three different things answering three different questions.

• Acute load — how much training you have done lately.
• Your load ratio — whether that amount is normal for you.
• Load focus — what kind of training it was.

Almost everyone reads the first, occasionally glances at the second, and has never opened the third. That is exactly backwards. The amount you have done is the least interesting of the three; the kind you have been doing is the one most likely to be quietly wrecking your training.

The three numbers, side by side

The number	What it measures	The question it answers	What to do about it
Acute load	Your accumulated load across roughly the last week, built from the intensity and duration of each recorded session	"How much have I done recently?"	Nothing, on its own. The raw figure is meaningless without the next row
Load ratio (acute against chronic)	That recent load set against your own longer-term average, as a position inside a personalised range	"Is that amount normal for me — or a jump?"	Decide whether to add volume, hold, or back off. The volume dial
Load focus	How your recent load splits between low aerobic, high aerobic and anaerobic work, each against a target band	"What kind of training have I been doing?"	Decide what your next session should be. The one that changes plans

A practical test for which one you are looking at: a single big number is acute load; a bar sitting inside a shaded range is the ratio; three bars with three separate targets is load focus, and you should keep reading.

Acute load: a score, not a measurement

Your acute load is the sum of the training load scores of your recent sessions. Each session's score comes from how hard it was and how long it lasted — Garmin does not publish the formula and the details differ between devices, so treat the figure as proprietary.

It is a score, not a unit. Not minutes, not kilometres. Your figure cannot be compared with anyone else's, and a bigger number is not better.

It is heart-rate driven. Your load figures are built on your heart rate data and on the intensity boundaries your watch thinks you have. Get those boundaries wrong and every load number downstream is wrong too.

The load ratio: the only honest way to read the amount

On its own, "my acute load is high" is not information. High compared with what?

That is what the ratio is for. Your watch holds a longer-running average of your load — your chronic load — and compares the recent week against it, as a position inside a range.

The range is derived from your own history, and on most Forerunner and Fenix watches your fitness level feeds into it as well. Two athletes with identical acute loads can have one sitting comfortably inside the range and the other well above it, and both are correct. I am deliberately not quoting the boundaries of the "optimal" band: there is no fixed figure to quote, because they move with your own training history. That is the entire point of the metric.

• Below your range — you have done less than you are used to. Fine during a taper, an illness or a deliberate easy week. Worth noticing if it has been weeks and was not a decision.
• Inside your range — your recent training is consistent with your recent history. Where most weeks should sit, and where it is safe to think about building.
• Above your range — you have made a jump. Sometimes a deliberate overload block; sometimes a race, a holiday week with time to train, or three hard sessions landing in five days by accident. The watch cannot tell those apart. You can.

One week above your range is a training decision. A month above it, with sleep getting worse and sessions feeling harder, is the pattern described in the common signs of overtraining.

Load focus: the number nobody reads, and the one that matters

This is the section worth the click.

Load focus takes several weeks of your training and splits it into three buckets, then shows each one against a target band. On most recent Garmin watches the buckets read roughly as:

• Low aerobic — easy, conversational, sustainable work, and the bulk of a well-built endurance week. Broadly what zone 2 training is for.
• High aerobic — harder sustained work, around the point where things stop being comfortable. Tempo and threshold sessions, so it depends heavily on where your watch thinks your lactate threshold is.
• Anaerobic — short, hard efforts clearly above that point. Intervals, hills, sprint finishes.

Each bucket gets its own target, and the useful readout is not the numbers — it is which bucket is short and which is over.

How athletes drift hard by accident

Here is the failure mode, and almost nobody checks for it.

Nobody decides to train too hard. It happens by accumulation. Your easy runs creep up a few seconds a kilometre because you feel good and it is only a few seconds. You run with a slightly faster group on Tuesdays. The hilly route becomes the default route. Each choice is reasonable. None of them felt like a change of plan.

Six weeks later, a large share of your training sits in the high aerobic and anaerobic buckets, your low aerobic bucket is well under target, and you did not choose any of that. You have no genuinely easy days to recover on and no genuinely hard days with anything left for them — every session is in the same uncomfortable middle.

This is, in my view, the single most common self-inflicted error in endurance training. It is why athletes plateau while training more, and it is nearly invisible from the inside, because every individual run felt fine.

Load focus is the one screen on your watch that shows it in two seconds.

What the drift costs you

• Your easy days stop being easy, so you arrive at hard sessions already tired and cannot hit the intensity that makes them worth doing.
• Your hard days stop being hard, for the same reason — the fatigue cost of intensity without the adaptation.
• Your recovery metrics sour at once. Elevated recovery time, a readiness score that never recovers, a resting heart rate drifting up. Four warnings that are really one problem.
• Your aerobic base quietly stops growing — the engine that decides how long you can hold anything.

What to do when a bucket is out of balance

Read the shortage, not the surplus. The bucket that is under target is the one that tells you what to do next.

• Low aerobic short, hard buckets full. The common case, and the fix is uncomfortable rather than complicated: make your easy runs properly easy for a few weeks. Slower than feels right. Keep the number of hard sessions, drop the intensity of everything between them.
• Low aerobic full, both hard buckets short. You have a base and no top end. Common in a deliberate base phase, and a problem four weeks before a race. Add one quality session, not three.
• Anaerobic short, everything else fine. Often harmless — plenty of endurance athletes need very little of it. It matters if your event has a sprint finish or repeated surges.
• Every bucket short. That is not a focus problem, it is a volume problem. Go back and read the ratio instead.

One caution: load focus looks back over several weeks, so it responds slowly, and both its availability and its exact labelling differ across the Garmin range. Give a change a few weeks before you decide it is not working.

Why your load numbers can be wrong before you read any of them

All three numbers rest on the same foundation: your heart rate data, interpreted against the intensity boundaries stored on your watch. If those boundaries are wrong, everything above is distorted — and the most common way for them to be wrong is a maximum heart rate you never set. Most watches start from an age-based estimate, and that estimate is wrong for a lot of people in both directions.

• A maximum set too low makes every effort read as a higher share of your maximum than it was. Easy runs register as high aerobic, hard runs as anaerobic, your acute load inflates, and your load focus tells you that you are training far harder than you are.
• A maximum set too high does the reverse. Hard intervals never cross into the anaerobic bucket, your load under-reads, and your focus screen invents an anaerobic shortage.

So before you act on any load reading, check whether your maximum heart rate is set correctly. It is the single setting that distorts the most other numbers, and almost nobody has looked at it. Boundaries anchored to a measured threshold rather than an age estimate are better still, for the same reason.

Load is accumulated training effect

The connection worth holding on to: Training Effect scores a single session for what it stimulated, and load is what those sessions add up to.

That is why the two screens disagree in ways that look like faults but are not. A two-hour easy run can produce a large aerobic Training Effect and a big contribution to your low aerobic load; a short interval session can produce a small aerobic effect, a large anaerobic one, and less total load than you expected. One describes a session, the other a month.

Load also feeds upwards: your training status is largely an interpretation of your load trend against the direction of your watch's own fitness estimate, which is why one unusual week changes your status without your fitness having changed. The full map of which metric feeds which is worth ten minutes.

How to read all three in under a minute

1. Check the ratio first, not the acute figure. Below, inside or above your range. That is your volume answer, and it takes two seconds.
2. Then open load focus. Find the bucket under target. That is your "what next" answer.
3. Ignore the raw acute number unless you are tracking it week to week against yourself.
4. Sanity-check the foundation once. If your maximum heart rate is an age guess, fix that before you trust any of it.

The honest limit of the whole screen is that it describes what you did. It does not know what you are training for, when your race is, or that you are away next week. Turning "my low aerobic bucket is short" into a different Tuesday session is still a judgement. Lactate Training syncs your Garmin activities and health data and uses them to build and adapt a plan, with zones anchored to a measured lactate threshold rather than an age-based estimate, so the shape of your week is a decision rather than a drift.

Frequently asked questions

What is a good Garmin training load?

There is no good number, and the raw figure cannot be compared between people. What matters is where your recent load sits inside your own personalised range: inside it means your training is consistent with your recent history, above it means you have made a jump, below it means you have eased off.

What is the difference between acute load and load focus?

Acute load is how much you have trained recently, as one accumulated score. Load focus is what kind of training it was, split between low aerobic, high aerobic and anaerobic work against target bands. Acute load bears on volume; load focus tells you what your next session should be.

Why is my Garmin training load so high when my training feels normal?

Usually an intensity boundary problem rather than a training problem. If your stored maximum heart rate is lower than your real one, every session reads as harder than it was and your load inflates. The other usual causes are an unnoticed jump in volume, and a hot or hilly week pushing your heart rate up at the same paces.

Is my load focus meant to be balanced?

Not equally balanced, no — each bucket has its own target band and the targets are not the same size. A well-built endurance week is mostly low aerobic work with a smaller amount of harder training. The useful signal is which bucket sits below its target, not whether the three are level.

How long does it take to change my load focus?

Several weeks, because the screen looks back over several weeks by design. One different session will barely move it. If you are correcting an accidental drift into hard training, hold the change for a few weeks before judging it.

Should I worry if my training load is above my optimal range?

One week above it is often a deliberate overload block, or just a week with more time to train, and is not a problem by itself. Take it seriously if it has persisted for several weeks alongside worsening sleep, a rising resting heart rate and sessions that feel harder than they should. One metric moving is noise; several moving together is evidence.

Decide the shape of your week, not just the size

Load focus can tell you that your easy running has quietly stopped being easy. It cannot rewrite next week around that, work out where your race fits, or move a session when you are travelling — which is the job Lactate Training does with the Garmin data you already have.

See how it works →