Two ways to use the same weights
Strength training in the traditional sense means one exercise at a time: a set of a few hard reps, a full rest, then the next set. Circuit training strings several exercises together with little or no rest between them, usually at lighter loads, and repeats the loop. The kit can be identical. What changes is the load you pick up and how long you wait before picking it up again.
Both count towards the muscle-strengthening part of WHO's guidelines when they work every major muscle group at moderate or greater intensity on two or more days a week. For the floor and equipment at one club, see strength training at RPM. Circuit formats such as EMOMs and AMRAPs are laid out in the functional circuits guide, so this page sticks to choosing between the two.
What each one builds, according to the research
| Quality | Heavy sets with full rests | Circuits with short rests |
|---|---|---|
| Maximal strength | The main target. ACSM advises loads of 1 to 6 reps with three to five minutes of rest once you are past the novice stage | Improves too: a 2021 meta-analysis of 45 studies found gains in upper and lower body strength |
| Aerobic fitness | Not what heavy sets are designed for | A 2017 meta-analysis found circuits raised maximum oxygen uptake in healthy adults |
| Muscular endurance | Not the focus, because sets are short and rests are long | ACSM's endurance advice looks like a circuit: light to moderate loads, more than 15 reps, under 90 seconds of rest |
| Muscle size | ACSM's muscle-building advice sits between the two: 6 to 12 reps with one to two minutes of rest | The 2021 meta-analysis also found an increase in muscle mass |
| Session length | Longer, because the rests add up | Shorter for the same number of exercises |
That 2017 analysis reported larger strength gains on lighter circuit loads, then noted that the people in those studies started less fit, which may explain it. Read it as a reason circuits work in your first months, not proof that they replace heavy sets once your lifts climb. For intermediate and advanced lifters, ACSM puts the emphasis on heavy loading.
Rest length is the real difference
Rest decides how much weight you can lift on the next set. A 2018 systematic review of 23 training studies found that strength improved even with rests under 60 seconds, but that trained lifters seem to need more than two minutes to get the most from their sets. For untrained people, 60 to 120 seconds looked sufficient, which explains why circuits suit the early months.
The same five movements, run both ways. Loads and reps are examples, so choose your own.
| Movement | As heavy sets | In a circuit |
|---|---|---|
| Squat | Barbell back squat, 4 sets of 5, about three minutes of rest | Goblet squat, 12 controlled reps |
| Hinge | Romanian deadlift, 3 sets of 6 | Kettlebell deadlift, 12 reps |
| Press | Bench press, 4 sets of 5 | Push-ups or a dumbbell press, 10 to 12 reps |
| Pull | Plate-loaded pulldown, 3 sets of 8 | Cable row, 12 to 15 reps |
| Carry | Heavy farmer's carry, 3 lengths with full rests | Lighter carry for one length, then straight back to the squat |
| Whole session | Roughly 50 minutes | Four or five laps in about 30 minutes, with a minute between laps |
The heavy version leaves you strong and unhurried. The circuit leaves you out of breath and finished sooner.
Which one suits you
| If you | Lean towards | Why |
|---|---|---|
| Want a bigger squat, bench or deadlift | Heavy sets | ACSM's strength advice centres on heavy loads with long rests |
| Have half an hour at lunch and want strength and fitness from it | Circuits | Short rests fit more work into less time |
| Are new to lifting | Either, technique first | ACSM's novice advice is loads you can lift 8 to 12 times, two or three days a week |
| Play a sport built on repeated efforts | Both | Strength for each effort, and the fitness to repeat them |
Pain, an injury, pregnancy or a medical condition changes the picture, so ask a doctor or physiotherapist before you choose either.
Running both in one week
In a single visit, do the heavy sets first and the circuit after. ACSM advises ordering exercises so higher-intensity work comes before lower-intensity work, which keeps your heaviest sets fresh. The ordering of the big lifts themselves is covered in compound lift training.
| Main goal | A week that fits | Keep in mind |
|---|---|---|
| Strength first | Three heavy sessions, with a short circuit after the lightest one | ACSM suggests adding 2 to 10 per cent to a load once you beat your target reps by one or two |
| Fitness first | Two circuit sessions and one heavy session | The heavy day keeps a strength anchor in the week |
| An even split | Two heavy days and two circuit days, alternating | Leave a day between the two hardest sessions where you can |
| Only two days a week | Heavy sets for the whole body, each finished with a short circuit | Meets WHO's two-day advice when every major muscle group gets worked |
In an Abu Dhabi week, Saturday or Sunday suits the longest heavy session, while a lunchtime circuit fits a working day or the shorter Friday hours.
Habits that blur the line
- Racing through heavy sets. Cutting the rest on a heavy squat turns a strength set into a grind with untidy reps.
- Loading circuits like strength days. If your form slips by the third lap, that weight belongs in straight sets.
- Holding four machines at the after-work rush. At busy hours, build circuits from kettlebells, a bench and a patch of floor.
- Logging nothing. Record loads for heavy sets and laps or time for circuits, so you can see either one move.
Heavy sets and circuits at RPM
RPM is one club, on Level 4 of AD HUB Sports Complex in Al Manhal. For heavy sets, the training floor photos show a squat rack with colour bumper plates, fixed-weight barbells, benches and dumbbells, with plate-loaded machines and multi-station cable towers alongside.
- Heavy days: ask on a tour where you can deadlift, whether bars may be dropped and how busy the rack is at your hour. A lifting platform is not confirmed, so ask if you need one.
- Circuits: the turf lane with its sled, the kettlebells, battle ropes and step boxes share the Mixed section's functional area.
- Women: the Ladies section has its own strength and cardio equipment. Which sections a membership covers depends on the tier, so confirm yours.
- Coaching: Engine adds coached programming and Atelier is built around 1:1 coaching. Group classes run in both sections, and the timetable changes.
Sources
- American College of Sports Medicine, position stand: Progression models in resistance training for healthy adults (2009)
- Grgic J, et al. Effects of rest interval duration in resistance training on measures of muscular strength: a systematic review. Sports Medicine, 2018
- Muñoz-Martínez FA, et al. Effectiveness of resistance circuit-based training for maximum oxygen uptake and upper-body one-repetition maximum improvements. Sports Medicine, 2017
- Ramos-Campo DJ, et al. Systematic review and meta-analysis of resistance circuit-based training. Biology, 2021
- World Health Organization, WHO guidelines on physical activity and sedentary behaviour (2020)
Questions, answered.
Will circuit training build muscle?
It can. A 2021 meta-analysis of 45 studies found circuit training increased muscle mass as well as strength. For the most muscle, ACSM leans on moderate loads of 6 to 12 reps with one to two minutes of rest, which sits between the two formats.
How long should I rest between heavy sets?
ACSM's position stand suggests three to five minutes for heavy sets of 1 to 6 reps. A 2018 review found that people new to lifting did well with 60 to 120 seconds, so start there and lengthen the rests as your loads climb.
Do circuits count as cardio?
A 2017 meta-analysis found that circuits raised maximum oxygen uptake, so they do train aerobic fitness. If fitness is your main goal, dedicated intervals give you closer control over effort, and the strength and HIIT comparison weighs that option.
Should a complete beginner start with heavy sets?
Start with moderate loads and clean technique in either format. The first eight-week routine sets out loads and progression for the early weeks.