If you skip your stretching and opt for another set of curls this new study will make your think twice if your looking to increase muscle size and strength.

Stretching is widely recognised for its benefits in increasing flexibility and range of motion (ROM), but recent research shows it can also contribute to muscle growth. A study published in early 2024 sheds light on how static stretching can promote muscle hypertrophy similarly to resistance training. Tim Wohlann and his team aimed to investigate the effects of stretching versus traditional resistance training on muscle thickness, strength, and flexibility of the pectoralis major (chest muscles) over eight weeks.

Eighty one participants were allocated either a static stretching, strength-training or control group. Pectoralis stretching was applied for 15 min/day, 4 days per week, while resistance training trained 3 days per week, 5 × 12 repetitions.

The results shocked the researchers and fitness enthusiasts alike.

The study found that static stretching alone can increase muscle thickness and hypertrophy. This means that stretching contributes to muscle growth.

The main takeaways from the study were:

1. Increase in Muscle Thickness: The study’s participants saw an increase in pectoral muscle thickness, even from static stretching alone. This was previously underappreciated, as hypertrophy was primarily associated with resistance-based exercises.

2. Enhanced Range of Motion (ROM): Unsurprisingly, stretching improved the ROM in the shoulder and chest, enabling participants to achieve better flexibility in the chest area.

3. Strength Benefits: Though strength gains were significantly greater in the resistance training group, those performing static stretching also showed modest increases in strength.

The study suggests that static stretching may stimulate muscle growth through a few possible mechanisms:

• Muscle Tension: Stretching involves applying prolonged tension to muscles, which can stimulate the mechanotransduction pathways known to trigger muscle protein synthesis. These pathways are often activated by resistance training, but they can also be activated through sustained muscle tension, as seen in stretching.

• Fascicle Lengthening: Long-duration stretching could lead to muscle fibre elongation. As fascicles (the muscle bundles) lengthen, they may respond by growing thicker to maintain optimal strength, contributing to hypertrophy.

• Cellular Response: The study indicates that stretching might trigger a cellular response similar to that of traditional resistance exercises. By placing muscles under consistent tension and stretch, a cellular signalling pathway is activated that promotes muscle fibre growth.

So what takeaways can you adopt in your fitness journey from this new research. Number 1 when exercising opt for resistance exercises that elicits a stretch or that challenges your range of movement. For example Romanian deadlifts, Cable chest flys or lunges. Number 2 Add stretching sessions to your weekly routine, ideally this should be done away from the gym in a relaxed environment using the following protocols.

Type: Static assisted and pre contraction stretching (post isometric relaxation PIR)

Frequency: minimum of 5 min per muscle group per week, 60-120 minuets full body total per week

Duration: 50 seconds per stretch

Intensity: 70-80% perceived intensity

Placement: Separate from exercise

The study by Wohlann et al is groundbreaking in demonstrating that static stretching can positively impact muscle growth. Adding stretching sessions will benefit overall muscular wellness and would complement any resistance training routines aimed at building muscle size and strength. While stretching does not replace the strength gains achievable through weight training, stretching 100% offers an effective supplementary strategy to improve muscle thickness as well as flexibility.