Built With Science founder Jeremy Ethier and Dr. Milo Wolf, PhD, of Sport Science, collaborated in early August 2024 to unravel research suggesting that training in loaded stretched positions can create significant muscle growth.
Focusing more on the stretch could [make] lagging muscles a lot bigger.
If it sounds too good to be true, recent studies show similar accelerated gains from optimizing tension in a stretched muscle. Moreover, using “bad” form could still have benefits. Ethier and Wolf explained common mistakes that cause many to miss out on these stretch-loading benefits.
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Mistake 1 – Lifting Too Heavy/ Short Reps
Many people, especially inexperienced exercisers, train with too much weight, which prevents them from moving through their full range of motion (ROM). They intentionally stop short of their full ROM to avoid the most challenging part of the exercise.
Common culprits for suboptimal form include not touching the bar to the chest during a bench press or performing half-rep squats. These exercises are more challenging in the stretched position.
It’s better to use less weight and train a muscle through its full motion, especially during compound lifts. The lift and stretch are equally important, as determined by several scientific comparisons using various testing methods (1).
Mistake 2 – Fast Negatives
Rep tempo, or how fast a rep is performed, can affect the quality of a loaded stretch. Whether lifting too heavy, lacking experience or having poor habits, many exercisers speed through reps, prioritizing the concentric while missing out on a good stretch.
Dr. Wolf recommends slower eccentrics, pausing for a second at the bottom position, and then lifting explosively.
Best Exercises To Challenge Muscles in the Stretch
Certain exercises combine stretching and tension better than others. If comparing chest presses, for example, a barbell stops at the chest, whereas dumbbells can lower past the chest for a better stretch.
Even better, says Dr. Wolf, are deficit push-ups where the upper body is elevated between two objects. As you lower, the pecs stretch as much as your range of motion allows.
Another way to enhance muscle growth is by using variations that place more tension on certain parts of a muscle. For example, preacher curls cause greater growth in the lower biceps than incline curls because they place more strain on the lengthened biceps near the elbow joint. (2)
The most significant comparison was a 2023 study that found 40 percent more muscle size when performing overhead triceps extensions versus triceps pushdowns (3).
5 Golden Exercises for Bigger Muscles
Below are exercises to prioritize for muscle growth:
- Preacher Curl (Biceps)
- Dumbbell Flye (Chest)
- Overhead Extension (Triceps)
- Reverse Cable Flye (Rear delts)
- Behind the Body Lateral Raise w/Cable at Wrist Height (Side delts)
Why “Bad” Form = More Gains
While core training fundamentals haven’t lost their relevance, exercise science is ever-evolving. Recent literature shows favorable gains when using “bad form” (i.e., half reps when a muscle is lengthened versus only full range of motion reps). (4)(5)
When you can’t do any more full range of motion reps, push past failure by doing half reps in that stretched position.
The best exercises to capitalize on partial rep gains include calf exercises, most back movements (e.g., lat pulldowns and rows], chest flyes, reverse flyes, dumbbell lateral raises, and leg extensions).
[Related: The 10 Best Exercises for Long-Length Partial Reps]
While the evidence for loaded stretch training benefits is promising, questions remain if it applies to all muscles and all parts of a muscle. To find answers, Ethier will partner with the University of British Columbia (UBC) in September 2024 to fund and participate in a study “To determine how much challenging the muscles in the stretch position leads to growth.”
They’ll use three custom machines that apply more tension during the stretch or contraction. The study will include tests for the chest, shoulders, and glutes.
“It’s a big project to take on, but it will help shape the way we work and the exercises we choose to maximize growth,” says Ethier.
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Featured image: @jeremyethier on Instagram