Rest between sets in Zyra Workouts defaults to 60 seconds on isolation exercises, 120–150 seconds on most compound lifts, and 180 seconds on the six heaviest barbell movements. Those defaults come from the exercise catalog, one value per exercise, and can be overridden per program exercise or in the session. The reasoning behind the ladder — and what the published guidance says — is below.
Zyra Workouts is in development and not yet on the App Store; the screens described here may change before release.
Rest by movement type (table)
Every exercise in the catalog carries a defaultRestSec of 60, 90, 120, 150 or 180. Across the 61 exercises the distribution is:
| Default rest | Exercises | What is in the bucket |
|---|---|---|
60 s | 25 | Isolation work: lateral raises, curls, pushdowns, leg extensions and curls, calf raises, core holds, plus push-ups |
90 s | 6 | Barbell curl, skull crusher, tricep dip, farmer's carry, hanging leg raise, ab-wheel rollout |
120 s | 12 | Mid-weight compounds: dumbbell and cable rows, lat pulldown, Arnold press, lunges and split squats, dumbbell RDL, good morning, glute bridge, chest dip |
150 s | 12 | Heavier compounds: dumbbell presses, barbell row and RDL, pull-up and chin-up, dumbbell overhead press, close-grip bench, leg press, hack squat, hip thrust |
180 s | 6 | Back squat, front squat, conventional deadlift, barbell bench press, incline barbell bench, barbell overhead press |
The design brief the catalog was built from gave two anchor examples — "lower-body compound 3:00, upper-body isolation 1:30" — and left the rest of the table open. The catalog landed on 180 s for the barbell compounds and went shorter than the brief for isolation work, at 60 s. Either number is a default, not a finding: it is what the timer counts down from when you tick a set.
Why compounds get three minutes
The ladder follows how much a set costs. A set of dumbbell lateral raises loads a small amount of muscle with a light weight; a set of back squats loads most of the body with a heavy one, and the next set is limited by whole-body recovery, not by the target muscle alone. Longer rest lets the next compound set be done with a load close to the last one, which is the whole point of counting sets against a target rep range.
The published guidance points the same way:
- The ACSM position stand on progression recommends 3–5 minute rests between sets for heavy strength loading (1–6 RM), 1–2 minutes for the 6–12 RM hypertrophy zone, and under 90 seconds for local muscular endurance work1.
- The 2018 systematic review by Grgic and colleagues (23 studies, 491 participants) concluded that strength can be gained with rests under 60 seconds, but that rests over 2 minutes appear necessary to maximise strength gains in resistance-trained people, while 60–120 seconds is sufficient in untrained people2.
Read against that, the app's 180 s on the heaviest lifts is the low end of the ACSM strength range and above the review's 2-minute line; the 60 s on isolation work sits in the endurance-to-hypertrophy band. Both are choices within the ranges, not the ranges themselves, and the review's own distinction — trained lifters benefit from more rest than untrained ones — is exactly the kind of thing a fixed default cannot see. A seated cable row at 120 s is a reasonable start; a strong lifter running it heavy may want the 150–180 s of the barbell row.
In plain terms: the heavier and more whole-body the lift, the longer the default; the guidance bodies say 1–2 minutes for growth-zone sets and 3–5 for heavy strength sets, and the app's numbers sit inside those bands.
What trials that changed only the rest found
The guidance above is mostly about strength. For muscle size the evidence is newer, and the effect is smaller than the gym debate suggests.
One direct trial. In 2016, Schoenfeld and colleagues randomised 21 young resistance-trained men to rest either 1 minute or 3 minutes between sets, with every other training variable held the same3. For 8 weeks both groups did three total-body workouts a week: 3 sets of 8–12 RM (repetition maximum, the heaviest load you can lift for that many reps) on 7 exercises. The 3-minute group gained significantly more on the 1RM (one-rep max) squat and bench press. Muscle thickness, measured by ultrasound, grew significantly more in the front of the thigh with 3 minutes; the triceps leaned the same way without reaching significance (p = 0.06)3.
The pooled view. In 2024, Singer and colleagues pooled the randomised studies that compared rest lengths with everything else controlled: 9 studies and 19 muscle measurements, 6 of the 9 studies in untrained people, each lasting 5 to 10 weeks5. They used a Bayesian meta-analysis, which reports a credible interval (the range the true effect most likely sits in) and the probability that an effect is real. Effects are standardised (SMD, the difference divided by the spread between people), so different measures can be pooled.
Rest over 60 s vs 60 s or less: difference in muscle growth · SMD
- Everyone grew. Growth overlapped heavily across rest lengths: about 0.48 with short rest and 0.56 with longer rest, before comparing the groups head to head5.
- Head to head, a small lean toward longer rest. Rest over 60 seconds came out slightly ahead for the arm (0.13) and the thigh (0.17), but both intervals crossed zero5.
- How likely, how big. The probability that longer rest helped at all was 74% for the arm and 88% for the thigh; the probability that the edge was bigger than small was 45% and 54%5.
- Whole-body measures leaned very slightly the other way (−0.08), from only 3 studies5.
- Past 90 seconds the analysis found no appreciable extra growth, and training to failure or stopping short did not change the rest effect5.
In plain terms: resting over a minute may give a little more growth; the edge is probably small, and it seems to stop adding up past about 90 seconds.
Why rest might matter: the reps you keep
The likely reason is not the clock itself. Short rest means you start the next set less recovered, so you manage fewer reps at the same load. Singer's team suggested the small benefit of longer rest is "perhaps mediated by reductions in volume load"5. Volume load is sets × reps × load.
A 2022 trial tested that idea. Twenty-eight people trained one-leg knee extensions twice a week for 10 weeks at 80% of 1RM, with a different protocol on each leg4. With 3-minute rest the quadriceps grew about 13.1% in cross-sectional area; with 1-minute rest, 6.8%. When the 1-minute leg did extra work to match the 3-minute leg's volume load, it grew 12.9%. When the 3-minute leg was held to the 1-minute leg's volume load, it grew 6.6%4. Strength rose by similar amounts in all four protocols, about 27% to 31%.
Quadriceps growth by rest length, with and without matched volume load · % CSA
Read against the app's defaults: the 120–180 s on compounds already sits past the 90-second point where the pooled data stopped showing extra growth. The 60 s on isolation work sits at the short end, where the 2024 analysis found a small, uncertain edge for resting longer. The 2022 trial suggests the cost of short rest is mostly reps lost, which extra work made back in that study. This is our reading of the studies; none of them tested the app.
In plain terms: rest long enough to repeat a good set. In these trials, the reps you kept mattered more than the minutes you waited.
What the studies found
| Study | Who was studied | Key result | Year |
|---|---|---|---|
| ACSM position stand1 | Expert review of training studies in healthy adults | 3–5 min between heavy strength sets; 1–2 min for 6–12 RM sets | 2009 |
| Schoenfeld et al., *J Strength Cond Res*3 | 21 young trained men, 8 weeks, 1 vs 3 min rest | 3 min: greater squat and bench 1RM gains and front-thigh growth; arms not significantly different | 2016 |
| Grgic et al., *Sports Med*2 | Systematic review, 23 studies, 491 participants | Over 2 min to maximise strength in trained lifters; 60–120 s enough in untrained | 2018 |
| Longo et al., *J Strength Cond Res*4 | 28 people, one-leg knee extensions, 10 weeks, 1 vs 3 min, volume load matched or not | Growth followed volume load (about 13% vs 7%), not rest length | 2022 |
| Singer et al., *Front Sports Act Living*5 | Meta-analysis of 9 randomised studies, mostly untrained young adults | Small, uncertain edge for over 60 s (arm 0.13, thigh 0.17 SMD); no clear extra past 90 s | 2024 |
Overriding the default
Three levels apply, from broadest to narrowest:
- Catalog default — the
defaultRestSecabove, used when nothing else is set. - Program exercise — each exercise in a program can carry its own
restSec, which wins over the catalog whenever that program day is started. - Session — the timer can be adjusted while training; changing it there does not rewrite the program.
A program built for strength on a 3–5 rep scheme is the common case for raising the compound rest toward the ACSM's 3–5 minutes; a short-session program is the common case for lowering isolation rest further or pairing exercises.
Supersets and rest
When two adjacent exercises are grouped as a superset, the app changes one thing about rest: the auto-rest timer fires only after the last member of the group is done. Ticking a set of the first exercise starts nothing; ticking the matching set of the second starts the rest. The timer duration is the second exercise's rest (default or override). That is the mechanism that makes a superset shorter than the two exercises done separately — the first exercise's rest is spent doing the second — and it is why the pairings that work are ones where the second exercise does not compete with the first for the same muscles. The superset page covers the pairings.
Limits worth knowing
- Small trials, read as abstracts. The 2016 trial had 21 men and the 2022 trial 28 people; we read the abstracts of both, not the full papers.
- Short and mostly untrained. The pooled studies ran 5 to 10 weeks, mostly in young untrained people, with too few trained-lifter studies to analyse separately5. Small differences could add up over longer spans.
- Limbs only. No torso muscles were measured, and training volumes were moderate5.
- One exercise. The 2022 trial used a single machine exercise per leg, not a whole program4.
- Funding. One author of the 2024 analysis declared a past advisory role with a fitness-equipment company; the others declared none5.
Latest research
The newest study we opened is a 2026 crossover trial in 22 recreationally trained men and women doing 4 sets of 8 bench presses at 75% of 1RM, once with 1 minute and once with 2 minutes of rest6. Average power fell across the sets under both rest lengths. Men and women completed different numbers of reps with 1 minute of rest, and the women held their power output better under both conditions6. It was a single session, so it says nothing about growth. It does show that the same clock can cost different people a different share of their next set. We read the abstract only. The 2024 meta-analysis above remains the newest pooled view on growth5.
The short version
Zyra Workouts rests 60 s after isolation sets, 120–150 s after most compounds and 180 s after the heavy barbell lifts, per exercise, overridable per program and per session. The ACSM puts heavy strength rests at 3–5 min and hypertrophy-zone rests at 1–2 min1; a 2018 review found over 2 min pays off for trained lifters2. For muscle size, trials that changed only the rest found a small, uncertain edge for resting over 60 s and no clear extra past 90 s5, likely because short rest costs reps4. Read the default as a countdown to edit, not a rule to obey.
Educational overview only — training guidance, not medical advice.
