The HIT workout tracker: time under load, slow cadence, and one honest set

Open Strong, Hevy, or Jefit and the first thing they ask is how many sets you plan to do. The rest-timer starts before you've logged the first rep. The weekly view shows total tonnage moved. These are excellent tools — for the protocol they were designed for, which is high-volume, multi-set bodybuilding.

They are not built for HIT. A High-Intensity Training session has one set per exercise, no rest timer to manage, no tonnage to track. What it does need recorded is precisely the data those apps don't surface.

HIT trades volume for honesty. The log has to make that honesty inspectable, week over week, or the protocol collapses.

The three numbers that matter

• Load. The weight on the bar or stack. This is the only number a standard tracker handles well.
• Time under load (TUL). The total seconds the muscle was under continuous tension before failure. A good HIT set lasts 60 to 120 seconds. Anything shorter means the load was too heavy to be controlled; anything longer means it was too light to recruit the fibres that grow.
• Honest failure. Did the muscle physically fail, or did you stop because the timer beeped, the rep count looked tidy, or you wanted to be polite to the person waiting? This is the variable a tracker can capture with a single tap and nothing else can.

Why generic trackers actively hurt HIT trainees

Tracking the wrong variables doesn't just waste screen space — it shifts behaviour. A volume-training app shows you accumulating tonnage and rewards adding more sets. A HIT trainee using that app gradually starts running extra sets to make the weekly number look better, undoing the protocol's central advantage: total recovery between sessions.

The right tracker hides the wrong numbers. No weekly tonnage. No rest timer. No "sets remaining." Just a 60–120 second tension window, a clear failure marker, and a comparison against the same exercise last week.

How progression works without sets and reps

In conventional logging, progression means adding weight, adding a rep, or adding a set. In HIT, there are no extra sets and reps-to-failure is a consequence, not a target. Progression is therefore tied to a single rule: if your time under load on a given exercise exceeds the protocol's upper bound (typically 90 or 120 seconds) on two consecutive sessions, the load goes up next time. If TUL falls below the lower bound, the load comes down. The tracker handles this — the trainee just shows up.

Volume training rewards what you did. HIT rewards what you stopped yourself from doing. The tracker has to make the second one visible.

Why this matters beyond logging

The point of a tracker is to make the right behaviour easy and the wrong behaviour awkward. A HIT tracker that surfaces TUL, failure, and slow cadence makes it almost impossible to drift into volume training. A volume tracker repurposed for HIT makes drift almost inevitable. Six months in, the trainee is running a hybrid protocol they did not choose, and the slow, brutal honesty that made HIT work in the first place is gone.

This is why Intensiq exists as a separate product rather than a preset inside Strong or Hevy. The protocol and the surface that records it have to be designed together. Anything else is a fitness journal with HIT written on the cover.

The proof

• McGuff D, Little J. Body by Science: A Research-Based Program for Strength Training, Body Building, and Complete Fitness in 12 Minutes a Week. McGraw-Hill, 2009.
• Westcott WL, Winett RA, Anderson ES, et al. Effects of regular and slow speed resistance training on muscle strength. Journal of Sports Medicine and Physical Fitness. 2001;41(2):154–158.
• Carpinelli RN. The size principle and a critical analysis of the unsubstantiated heavier-is-better recommendation for resistance training. Journal of Exercise Science & Fitness. 2008;6(2):67–86.

Read next: Strong vs Hevy vs Intensiq, The minimum-effective workout tracker, Time under tension, the complete guide.