Which running app tracks strength training best?

All of them record a strength activity and none of them model its cost properly, because their load models are defined as intensity relative to an endurance threshold and resistance training has neither term. Manual load entry exists in several and it is a guess layered onto a model built from measurements.

Can you track TSS for weight training?

Not meaningfully. Training Stress Score is intensity relative to threshold power or pace multiplied by duration. A set is thirty seconds and there is no threshold power for a squat, so any figure you enter is an estimate on a scale that was not built for the input.

Does Strava track weight training?

It records the session with a duration and an estimated calorie figure. It does not record sets, reps, load or reps in reserve, and nothing in the platform progresses a lift or models resistance-training fatigue.

Why does my training readiness say I am fresh after a heavy leg day?

Because readiness models are built on cardiovascular data, and a heavy set of three barely raises your heart rate while costing you two days. Mechanical and neural fatigue do not appear in heart rate, so every wearable and platform that infers training cost from it misreads lifting.

What is the best free option?

Intervals.icu for the endurance analysis, plus a free lifting log. It is genuinely excellent and free, and it will not compute anything that needs both halves — which is the trade.

The Best Running App That Also Tracks Lifting

What that looks like in practice

Two situations, both common, both misdiagnosed.

Your form curve says fresh and your legs disagree. Three heavy lower-body sessions this week plus moderate running. Training Stress Balance looks excellent. Thursday's threshold session falls apart and nothing in the model predicted it.

Your ramp is measured on half your load. You add lifting volume while holding running steady. The platform reports a flat, sustainable build. Your actual total training load rose substantially and the model has no way to say so.

Neither is a bug. It is a model doing exactly what it was designed to do, applied to an athlete it was not designed for.

Why manual TSS entry does not fix it

Several platforms let you enter a load figure by hand for a strength session, and it is worth being clear about why this is not a solution.

The number you enter is a guess. Layering a guess onto a model whose other inputs are measured makes the output harder to interpret, not easier — you now have a fatigue curve where some of the fatigue is measured and some is invented, and no way to tell which part is driving a given reading.

You would be better off knowing the model excludes lifting than believing it includes it.

The options

Strava

The strongest network in endurance sport, the best activity record, and unmatched route and segment data. If those are what you want, nothing replaces it.

Lifting: a duration and a calorie estimate. No sets, no reps, no progression. Its energy estimates were not built to drive nutrition decisions and should not be used for them. Full comparison.

TrainingPeaks

The professional endurance coaching platform, and if you work with a coach who lives in it that fact outweighs everything else here.

Lifting: effectively outside the TSS model. Full comparison.

Intervals.icu

The best free endurance analysis tool available, with depth that rivals paid platforms and an API people genuinely build on.

Lifting: manual estimate at best, same structural limitation. Full comparison.

Garmin Connect

Free with the watch, mature endurance metrics, HRV status, Body Battery.

Lifting: records it, with rep detection on some models. Its load and readiness models are cardiovascular, so a heavy triple reads as easy. Full comparison.

Base

Resistance training is first-class rather than an activity type: sets, reps, load and reps in reserve, with a progression rule that consumes RIR and a deload trigger that reads both training loads together.

Its endurance load model is deliberately cruder than any of the above — total minutes against a four-week average — and that is a real trade. It buys completeness: minutes needs no power meter and no calibrated threshold on every session, so the load history has no holes in it. TrainingPeaks and Intervals.icu do season periodisation better and Base does not attempt it.

Where it is weaker: in beta, no swim support, no structured workout push to a device, and no coach-athlete workflow.

The comparison

	Strava	TrainingPeaks	Intervals.icu	Garmin	Base
Endurance load model	Basic	TSS/CTL/ATL/TSB	Deep, free	Mature	Deliberately crude
Threshold handling	Zones only	Excellent, per sport	Excellent	Good	Run and ride, with confidence
Swim	Yes	Yes	Yes	Yes	No
Structured workout push	No	Yes	Partial	Yes	No
Sets, reps, load, RIR	No	No	No	Rep detection	Yes
Lifting in the fatigue model	No	No	No	Barely	Yes
Nutrition and measured maintenance	No	Basic	Limited	Imported	Yes
Session grading	Time in zone, after	Compliance	Analysis	Compliance	Per rep or time-in-zone
Price	Freemium	Paid	Free	Free with device	Beta

The stack that actually works

Being honest: for most runners who lift, the answer is not one app.

Intervals.icu or your watch platform for the endurance analysis — the curves, the season view, the power and pace history. Nothing here replaces that.

Something that reads both loads for the decisions a single-discipline platform structurally cannot make: whether your surplus survived the training week, whether two fatigue signals are firing, and whether your easy runs were actually easy.

The overlap between those two is nearly zero, which makes the combination cheap.

The one thing to fix first

If you only change one thing, change how your calorie target is produced.

Running costs roughly 1 kcal per kilogram of bodyweight per kilometre. For a 155 lb runner at 40 miles a week that is about 700 kcal a day. A target from an activity dropdown cannot see it, and the consequences — lost muscle, poor recovery, stress fractures — arrive slowly and get attributed to training rather than to eating. Measure it instead.

What to do next

Look at your platform's readiness or form reading on the day after your heaviest lifting session. If it says you are fresh, you now know exactly what that number is not counting.