HR at S0 (hrS0)

Definition

In TRIPS, hrS0 is the heart rate associated with your S0 anchor.

In plain language, it is the heart rate that best matches your economical flat-ground baseline pace.

That means hrS0 is not supposed to be:

• your average hiking heart rate
• your threshold heart rate
• your highest sustainable all-day heart rate

It is a baseline anchor that helps TRIPS interpret where your economical walking state sits inside your broader heart-rate range.

Why hrS0 matters

TRIPS uses several heart-rate-related anchors to interpret effort.

hrS0 matters because it helps define where your baseline walking state sits between:

• resting heart rate
• higher sustainable effort

If hrS0 is set unrealistically low or high, the planner can interpret your baseline effort in a way that does not really match you.

So even though many users should leave the default alone at first, hrS0 still matters as part of the overall physiology anchor picture.

Where the default comes from

TRIPS gives users a derived default instead of forcing everyone to guess a baseline heart rate for their walking anchor.

That default is a midpoint-style assumption based on your broader heart-rate anchors.

The important user-facing point is:

• the default is a starting estimate
• not a personal physiological measurement

What makes a good hrS0 value

A good hrS0 value should be:

• tied to the same baseline state as S0
• repeatable
• measured under reasonably controlled conditions
• consistent with your S0 anchor

Good evidence:

• a treadmill-style anchor test
• a repeatable flat-ground heart rate tied to your real baseline pace
• a known value you trust more than the default

Weak evidence:

• a heart rate copied from steep terrain
• a value from a highly fatigued day
• a number chosen because it makes the effort story look nicer

Relationship to S0, E0, hrRest, and hrAeT

hrS0 works best when interpreted together with:

• S0, your baseline speed anchor
• E0, your baseline energy-per-distance anchor
• hrRest, your lower heart-rate anchor
• hrAeT, your upper heart-rate anchor for planning interpretation

Those anchors are supposed to describe the same general physiological baseline.

That is why overriding just one of them casually can make the whole set less consistent.

What hrS0 is not for

hrS0 should not be used as:

• a route-output tuning knob
• a shortcut for making effort bands feel nicer
• a substitute for better baseline physiology inputs

If route interpretation looks off, the first things to revisit are:

• whether hrRest is grounded
• whether hrAeT is grounded
• whether S0 actually reflects your real baseline pace

before trying to invent a cleaner hrS0.

Default versus manual override

For many users, the default is the correct first choice.

That is especially true if:

• your resting heart rate is grounded
• your aerobic-threshold estimate is grounded
• you do not have a controlled test result for your baseline walking pace

A manual override makes more sense when you have strong evidence that the default clearly misrepresents your real baseline heart-rate anchor.

Guidance

For most users:

• leave hrS0 on the default at first
• override it only if you have evidence tied to your real baseline pace
• avoid tuning it only to make the planner outputs look nicer

The best question to ask is:

What heart rate best represents my normal economical flat-ground baseline pace, not the heart rate I wish it were?

Notes

• hrS0 is the heart rate associated with your S0 anchor.
• The default is a starting estimate, not a personal measurement.
• hrS0 works best when interpreted together with S0, E0, hrRest, and hrAeT.
• Most users should leave the default alone unless they have better evidence.