Blog
Training, explained
Periodization, hybrid training, and tracking. From the team behind Zirv.
Latest
Treadmill vs outdoor running: what changes in your tracking data
Why treadmill runs need a different tracking pipeline than outdoor runs, what a tracker can and can't measure on a belt, and how to read your data accordingly.
2026-08-07 · 5 min read
2026-08-05 · 4 min read
Rep PRs vs load PRs: reading progress when the bar weight doesn't move
Why more reps at the same weight is still a real personal record, how Zirv scores that against a heavier lift, and what a stalled top-set weight actually tells you.
2026-08-03 · 5 min read
Rest between sets: how long to wait and why it changes with the lift
How rest periods between sets differ for strength versus hypertrophy work, why supersets remove the question entirely, and how to judge your own rest by feel instead of a fixed clock.
2026-07-31 · 6 min read
How many sets per muscle per week: reading training volume from your log
Why weekly sets per muscle group is the volume number worth tracking, how counting it goes wrong by hand, and how to read the trend once your log does the counting.
2026-07-29 · 5 min read
Linear vs undulating periodization: what the difference looks like in a real week
How linear and daily undulating periodization actually change your sets and reps week to week, with a worked example.
2026-07-27 · 4 min read
Live Activities for workouts: glanceable tracking without opening your phone
How Zirv's iOS Live Activity decides what to show on your lock screen, when it updates, and what actually lands on your Apple Watch.
2026-07-24 · 4 min read
Pause-aware pace: why your average pace lies when you stop at lights
Why average pace calculated from total elapsed time undersells your effort, and how moving time fixes it.
2026-07-22 · 5 min read
Auto-pause on your runs: what it should catch and what it should ignore
How auto-pause decides you have actually stopped, why it watches two separate signals, and where it deliberately does nothing at all.
2026-07-16 · 5 min read
Interval running workouts: structuring work/rest that progresses
How to structure interval running with work/rest ratios and heart rate zones, and how to progress intervals week to week without guessing.
2026-07-16 · 4 min read
Why offline-first matters in a gym with bad reception
Gyms are concrete boxes with terrible signal. What offline-first actually means in a workout tracker, and why a sync spinner mid-set is a design failure.
2026-07-14 · 5 min read
Estimated 1RM: how to track strength without maxing out
What estimated 1RM is, the formulas behind it, and why charting e1RM from everyday working sets beats testing a true max.
2026-07-14 · 5 min read
Heart rate zones for running: what the numbers mean
How the five heart rate zones are calculated, what each one trains, and how zone data turns a raw bpm number into a training decision.
2026-07-14 · 4 min read
Running cadence: what steps per minute actually tells you
What cadence measures, why there is no magic 180, and how to read your steps per minute without chasing someone else's number.
2026-07-14 · 4 min read
What your tracker should say mid-run (and when it should shut up)
The audio cues that actually help mid-run, the ones that are noise, and the design rules that keep voice feedback rare and useful.
2026-07-13 · 5 min read
Supersets and alternates: programming beyond straight sets
How pairing exercises into supersets and swapping in alternates changes what a workout log actually needs to track, and how Zirv handles both.
2026-07-06 · 5 min read
How to plan a deload week (and why your app should do it for you)
What a deload week actually changes, why picking the date by calendar guesswork misses the point, and a data-driven alternative.
2026-07-06 · 4 min read
RPE explained: logging effort, not just weight
What RPE actually measures, why the same weight can mean two different things, and how logging effort turns training data into something you can act on.
2026-07-06 · 6 min read
Strength and running in one week: how to program hybrid training
A practical weekly framework for fitting lifting and running together so neither one cancels out the other's progress.
2026-07-06 · 3 min read
What progressive overload actually is (and how to automate it)
The principle behind every effective strength plan, and why running it by hand falls apart after week three.
