Lifting and lowering weights builds muscle, obviously. But did you know weighted stretching does too? Here’s how and when to do it.
Stretch and Grow!
We know lifting and lowering weights leads to muscle growth as long as it’s done with high effort. Well, the same is true with stretching. The “high effort” part is key. If normal stretching led to muscle growth, we’d have jacked yoga moms winning the Ms. Olympia!
Normal stretching won’t do much to build muscle, but that doesn’t mean stretching can’t lead to muscle growth. After all, a lot of people lifting weights aren’t gaining muscle either: they simply aren’t doing it with a high enough level of strain and effort.
Those who do will get bigger and stronger. And stretching with the proper level of effort can do the same (1, 2, 3).
Loaded Stretching: How to Do It
The best way to ensure the proper level of strain and effort is to stretch against an external load. It’s something I’ve been using for over 20 years. It’s also been in the toolboxes of experts like Dante Trudel, John Meadows, John Parillo on the bodybuilding side, and Jay Schroeder and Dan Fichter on the performance side.
Using an external load you’re trying to resist (yielding isometrics) while in a lengthened position is a surefire way to make the muscle fibers produce tension while you’re stretching them.
In reality, this type of work is really a veeeeery slow eccentric/negative action. As muscles fatigue under load, they’ll resist less and less – the weight will move down very slightly. It’s barely noticeable, but there’s a gradual increase in stretch depth.
This form of training effectively stimulates muscle growth, especially if done as a supplement to regular weight training and performed at the end of your workout. Lifting and loaded stretching work via different and complementary mechanisms.
We’ll go further in depth below, but the steps are simple:
- Use a challenging load.
- Do an exercise where the target muscles are still under load when they’re in the most lengthened position.
- Go down to the lowest point you can reach in the range of motion.
- Hold the weight there. Even better, voluntarily tense and flex the muscle while it’s in the lengthened position.
- Hold for 60 to 90 seconds. Rest a couple of minutes and do 3-5 total sets.
For this to trigger hypertrophy, the set must reach a point where you’re working really hard and straining under the load. If you pick a set duration of 60 seconds, then it should be hard to complete that 60 seconds. You should want to give up around 45 seconds in.
Proper Stretch Duration
After tons of experimentation, I concluded that (for hypertrophy) doing sets of loaded stretching lasting more than 90 seconds isn’t necessary and can become counterproductive.
So perform sets of 60 to 90 seconds with a very challenging resistance. I’ve found that 2-3 minutes of rest between sets is best for hypertrophy. Less than that leads to too much central fatigue and makes each set less effective.
Here are the loading parameters:
- Do 3-5 sets of 60-90 seconds with 2-3 minutes of rest between sets.
- Do one or two loaded stretches at the end of each workout. If you’re doing two, use an alternating format:
- Exercise 1 – Set 1
- Rest 2 minutes
- Exercise 2 – Set 1
- Rest 2 minutes
- Exercise 1 – Set 2
- Rest 2 minutes
- Exercise 2 – Set 2
- Rest 2 minutes
- Exercise 1 – Set 3
- Rest 2 minutes
- Exercise 2 – Set 3
You can use any exercise where your target muscle is under tension. However, I’d recommend more “general” exercises to get a muscle-building stimulus on several muscles at once. That’s simply from a time-saving perspective since loaded stretching can be fairly time-consuming.
For that strategy, I use the dumbbell bench press, split squat, and Jefferson curl. You can also use a more targeted strategy when you want to use loaded stretching specifically to fix a lagging muscle.
Here are some examples:
- Biceps: Maltese Stretch
- Glutes: Folded Split Squat Stretch
- Calves: Standing or Seated Calf Stretch
- Traps: Shrug Stretch Hold (ideally with a slight forward bend)
Note: The pecs and anterior delts don’t really need a targeted movement. The dumbbell bench press stretch (pecs, anterior delts) and biceps Maltese stretch (anterior delts) are effective for these muscles.
The Science: Why Does It Work?
The main driver of hypertrophy is muscle fiber tension. If the fibers are required to produce a high enough level of tension – to a point where the effort becomes very demanding – you’ll trigger muscle growth pathways.
It doesn’t matter if the tension is present during a concentric, eccentric, isometric, or “stretching” action. If both variables are present (high tension to the point of significant difficulty), it will stimulate growth.
And there might be additional benefits to having those conditions present while you’re stretching a muscle:
- An increase in the IGF-1 receptor sensitivity.
- An increase in IGF-1 level if the duration and effort are sufficient.
- A hypoxic effect from decreased oxygen uptake into the muscle – the stretch plus contraction compresses the capillaries, making it much harder for blood to come in or out of the muscle.
- A bias of muscle-fiber recruitment toward the fast-twitch fibers, which don’t require oxygen because of the hypoxic state. This would allow you to have the fast-twitch fibers under tension for a long time, providing a very strong growth stimulus.
- An increased tensile strength in muscle fibers during their lengthened position, which would significantly reduce the risk of injuries.
- An increase in muscle growth, mostly in the part of the muscle closer to the tendons. This also reduces the risk of injuries.
Are There Drawbacks?
As with every training method, there’s a trade-off. Aggressive stretching, even if it’s loaded, will decrease strength for up to 30 minutes.
This happened to T Nation contributor Tom Sheppard. When he did loaded stretching for his pecs to start his workout, his strength dropped by 10 percent! But don’t be scared by that effect – it’s transient. In fact, loaded stretching can make you stronger.
The reason why it decreases strength for 20-30 minutes afterward is that stretching will…
- Reduce motoneuron excitability. It makes muscles less sensitive to excitatory drive, basically causing them to relax.
- Decrease tendon and muscle stiffness.
- Cause significant central fatigue.
These factors reduce force production potential both by lowering voluntary force production and the contribution of the stretch reflex. So this is a method better used at the end of your workout. And I see a further benefit to doing loaded stretching while the muscles are pumped from the workout.
Another potential drawback is the significant amount of central fatigue caused by loaded stretching. Central fatigue is a weakening of the signal from the nervous system to the muscles. A weaker signal makes it harder to recruit fast-twitch fibers. As a result, strength and power potential go down. It also makes it harder to stimulate growth.
Central fatigue is caused mostly by afferent signals from the muscles, tendons, and fascia to the nervous system. Those signals relay information to the CNS regarding what’s going on when doing the exercise. Pain, discomfort, and effort signals will cause an inhibition in the CNS, leading to the weaker excitatory drive we discussed.
A properly done loaded stretch is very uncomfortable and painful for 60-90 seconds. The result? Loaded stretching can lead to central fatigue accumulation. But it won’t matter if you do it at the end of your workout. Even if performance potential decreases, it’s not a problem if you don’t have to perform anymore. Doing the loaded stretch at any other point in the workout will negatively impact the rest of the session.
Too Many Benefits to NOT Do It
The simple fact that loaded stretching will represent a novel training stimulus – leading to immediate growth – should motivate you to add this training method to your program.
But its benefits go way beyond that. From increasing mobility to reducing the risk of injuries and improving muscle resilience, it’s truly a “jack of all trades.” If you’re an athlete, it must be in your program! And if you’re just trying to look and feel better, the return on investment is huge.
- Warneke K et al. Long-Lasting Stretching Induces Muscle Hypertrophy: A Meta-Analysis of Animal Studies. J. of Sci. In Sport and Exercise. 21 October 2022.
- Nunes JPO et al. Does stretch training induce muscle hypertrophy in humans? A review of the literature. Clin Physiol Funct Imaging. 2020 May;40(3):148-156. PubMed.
- Warneke K et al. Sex differences in stretch-induced hypertrophy, maximal strength and flexibility gains. Front Physiol. 2023 Jan 4;13:1078301. PubMed.