Intra-Set Passive Stretching: Does Stretching Between Sets Increase Muscle Growth?

Does stretching between sets increase muscle growth? Possibly a little, in some muscles, but nobody has shown it reliably. The human trials are small, short, and they disagree with each other. On heavy lifts the stretching also seems to cost you training volume.

Here is the idea, the studies, and a sensible way to test it without wrecking your workout. This is one narrow corner of range of motion and stretch-mediated hypertrophy, so if you want the bigger picture on training muscles at long lengths, start there.

What is intra-set (inter-set) passive stretching?

You finish a set of cable flys. Instead of standing around checking your phone, you hold the chest in a stretched position for 30-45 seconds. Then you start the next set.

That is it. No extra sets, no extra time. The pitch is “free” stimulus hiding in your rest period. Strictly, this is inter-set stretching (between sets), which is the term the research uses. People online often call it intra-set stretching, and some also mean a stretch held mid-set. This article covers the between-set version, because that is what has been tested.

The reasoning, laid out in a 2022 review by Schoenfeld and colleagues, is that stretch can switch on anabolic signaling through both active force (lengthening contractions under load) and passive force (the muscle being stretched) (Schoenfeld et al., 2022). The same paper is careful to say that longitudinal research on stretching between sets is limited, and that some of it suggests a benefit.

Notice the word “suggests”. It matters for everything below.

Why would stretching between sets work?

Two ideas get repeated online. Both are plausible. Neither is proven in lifters.

Idea 1: passive tension at long muscle lengths. Muscles that are stretched while loaded or stretched hard seem to be a stronger growth signal. A 2025 review of sarcomerogenesis (adding sarcomeres in series) concluded that high active or passive forces at long fiber lengths appear to be the key triggers (Blazevich et al., 2025). But its strongest evidence came from animal studies, and the authors said too few human studies exist to draw conclusions. For the full mechanism debate see our guide to stretch-mediated hypertrophy and sarcomerogenesis.

Idea 2: restricted blood flow (the ischemia theory). Holding a stretch might keep the muscle under metabolic stress during rest. I looked for direct human evidence behind this specific claim and did not find any among the studies reviewed here, so treat it as speculation.

What do the human trials actually show?

A 2020 review of human stretch training found that of 10 studies, only 3 saw positive effects on muscle structure, and those used an assisting apparatus or an external load. Of 5 studies that added stretching to resistance training, 2 applied it between sets and showed enhanced growth. The authors concluded that low-intensity passive stretch does not appear to help, while loaded stretch or stretch between contractions may, with limited evidence (Nunes et al., 2020).

Now the individual trials, in the order they help us understand the picture.

The favourable one: untrained adults, 8 weeks

Evangelista and colleagues split 29 sedentary adults into traditional training (17 people) or the same training plus a maximum-amplitude, 30-second passive stretch between sets (12 people). Both groups did 6 exercises, 4 sets of 8-12RM, with 90 seconds of rest, twice a week for 8 weeks (Evangelista et al., 2019).

Strength was similar. Muscle thickness grew in every site for both groups. But at the vastus lateralis (outer quad), stretching groups gained 17.0% versus 7.3%, and the sum of the four sites rose 10.5% versus 6.7%.

Read the authors’ own conclusion, though. They said the data were not enough to conclude that stretching between sets beats traditional training, only that adding it did not compromise adaptations in the first 8 weeks in untrained people. Twelve people in one group is a thin base for big claims.

The neutral ones: trained lifters and a one-leg design

In a 5-week trial, 16 untrained men trained flywheel squats twice a week, with one leg randomly assigned to inter-set stretching and the other leg as control. Flexibility improved more on the stretching side, isometric knee extension strength rose more, but quadriceps thickness did not differ significantly (7.3% vs 8.0%) (Nakamura et al., 2021).

An 8-week trial in 22 recreationally trained men and women compared the two approaches directly. Stretching lowered total training volume. Strength gains were similar. No significant between-group differences appeared for any strength or muscle outcome (Businari et al., 2024). Triceps thickness rose in the stretching group, but the groups did not differ.

The acute cost

In one crossover study, 17 trained men did 7 sets of seated cable fly at 10RM. Between sets they either stretched the chest for 45 seconds or rested passively. Stretching produced lower total load lifted, less muscle swelling and lower blood lactate than passive rest (de Camargo et al., 2022). The authors suggested using it on lower intensity days to reduce session stress.

Why do the studies disagree?

Several things differ, and any of them could explain the mixed results.

• Who was tested. Beginners grow from almost anything, so a trial that finds a difference in beginners may not carry over to people with years of training.
• Which muscles. Gains varied by site. The Evangelista result was strongest at one quad site and flat at others.
• Stretch dose and intensity. 30 seconds at maximum amplitude is not 45 seconds at “comfortable”.
• Total volume. If stretching leaves you fatigued, you might lift less, which can cancel a small bonus.
• Sample size and duration. All of these trials are small and 5-8 weeks long. Differences of a few percent in muscle thickness can come from measurement noise alone.

This is early-stage science. Not a verdict.

What do the bigger reviews say about stretching and growth?

Zooming out helps, because inter-set stretching is a subset of the wider static stretching literature.

A 2024 meta-analysis of 25 studies concluded that the chronic effect of static stretching on hypertrophy is unclear, with a trivial point estimate (SMD 0.118). Trained individuals showed larger effects than recreationally trained or sedentary people, and longer total stretching time was linked to bigger gains. The authors said stretching may not be very effective unless training duration is high (Arntz et al., 2024).

A separate 2024 meta-analysis of 42 randomized trials with 1,318 participants found a small but significant hypertrophy effect (d = 0.20), larger with longer stretch durations and intervention periods (Warneke et al., 2024).

Two meta-analyses, two readings of roughly the same message: modest at best, dose matters, certainty is low. And these cover stretching in general, not specifically between sets.

Does stretching between sets hurt your next set?

It can. The two studies that measured workload in trained lifters both found a cost: lower total training volume over 8 weeks in one, and less total load lifted in a single cable fly session in the other.

That matters because rest itself is a lever. In a trial of 21 trained men, 3-minute rests produced greater quadriceps thickness and strength gains than 1-minute rests over 8 weeks (Schoenfeld et al., 2016). Stretching does not shorten your rest, but if it leaves your muscle more tired when set two starts, you pay for it in reps. Our guides on 2-3 minute rests versus short rests and the penalties of short rest explain why reps matter so much.

Picture a lifter who stretches hard through the rest period and then gets 7 reps on set two instead of 10. Same time, less work.

Where does it make sense to try it?

Think of where the fatigue cost is smallest and the stretch is easy to hold.

Good candidates, where the stretch is easy to hold and fatigue costs little:

• Cable or pec dec flys for the chest.
• Leg extensions for the quads.
• Calf raises. A calf stretch is simple to hold, and our calf hypertrophy guide covers the exercises themselves. I could not confirm a calf-specific inter-set trial for this article, so I would not promise a calf-specific result.

How to test inter-set stretching safely

If you want to try it, run it as a clean experiment rather than an all-in lifestyle.

1. Pick one or two isolation exercises. Leave your main compounds alone.
2. Stretch for 30-45 seconds. That is the range the trials used. Use a firm, tolerable stretch. No bouncing, no pain.
3. Keep your normal rest. Do not shorten your recovery. Stretch inside it.
4. Log your reps. Write down reps and load on set 2 and set 3. If they fall compared with your usual numbers, drop it.
5. Give it 8 weeks. Most of the trials ran 5-8 weeks. Two weeks tells you nothing, and even after 8 weeks you will not be able to measure small growth differences by eye, so judge it mainly on whether your performance holds up.
6. Compare with a baseline. Use the same weekly set count, which you can check with our training volume calculator.

Watch the clock. If you start holding the stretch past your usual rest, the session quietly gets longer, which removes the main selling point.

What should you do instead if you want more stretch stimulus?

Before you add a new trick, check the basics that have stronger support. Train through a full, controlled range. Use exercises that load the muscle at long lengths. Our guides to long muscle length training and lengthened partials cover those methods, and they use the set itself as the stimulus rather than the rest gap.

Also compare it to the post-workout stretching people do for soreness. That is a different goal with a different answer, covered in stretching after workouts and soreness.

If you need a structured plan to run these ideas in, the free push pull legs plans are a good base.

When to skip it or see a doctor

Skip the experiment if you are recovering from a muscle strain or tear, have a hypermobile or unstable joint, or feel pain rather than a stretch. A pop, sharp pain, numbness or joint pain that lingers after training is a reason to stop and see a doctor or physiotherapist. A stretch in a fatigued muscle should feel like tension, not injury.

The bottom line

Stretching between sets is an interesting idea with a thin evidence base. A few small trials show a benefit at some sites, others show nothing, and trained lifters tend to lose training volume when they do it. None of it is strong enough to rewrite your program.

If your sets, your load progression and your rest are already solid, you can run a careful 8-week test on isolation exercises. If they are not, fix those first. That is where the real growth is.