Stretching before exercise has long been considered a common practice among athletes and fitness enthusiasts. However, recent studies have shed light on the potential drawbacks of static stretching before certain types of workouts, particularly resistance training.
This blog post examines the findings of various research studies that investigate the effects of stretching on muscle strength and size. Specifically, we will focus on the reasons why static stretching before resistance training might not be the best approach for maximizing muscle hypertrophy.
Comparing Flexibility Training Before Resistance Training (FLEX-RT) with Resistance Training Without Flexibility (RT)
In one study, participants were assigned to either RT or FLEX-RT groups. Both groups performed leg extensions, but FLEX-RT incorporated static stretching before the resistance training. After 10 weeks, the results showed that the RT group had higher numbers of repetitions and training volume. Additionally, the muscle size increased more significantly in the RT group (12.7%) compared to the FLEX-RT group (7.4%). While both groups exhibited similar strength gains, these findings suggest that flexibility training before resistance training may reduce muscle hypertrophy.
Stretching Effects in Elite Athletes
A study conducted with 15 elite male athletes from football and basketball examined how different durations of stretching affected muscle strength. The athletes performed stretching exercises after jogging, with varying durations of 15, 30, and 45 seconds. The results revealed that 15 seconds of stretching increased muscle strength, while 30 and 45 seconds of stretching led to a decrease in strength. These findings emphasize the importance of optimizing stretching protocols to enhance athletic performance.
Static Stretching and Muscle Strength in Sedentary Individuals
Another study analyzed the impact of static stretching on knee muscle strength in 14 sedentary women. Similar to the previous research, the participants engaged in static stretching exercises. The results indicated that the muscles became weaker at both slow and fast speeds due to static stretching. This study aligns with previous research findings, further highlighting the potential detrimental effects of stretching on muscle strength, especially for sedentary individuals.
Stretching for Muscle Recovery in Active Men
In a separate study, researchers explored the effects of different levels of stretching on muscle recovery after eccentric exercise in 30 active men. The participants were divided into high-intensity stretching, low-intensity stretching, and control groups. The stretching exercises were performed for three consecutive days after the new exercise. The results demonstrated that low-intensity stretching was likely more effective in reducing muscle soreness and improving muscle strength compared to high-intensity stretching or no stretching. However, it is important to note that stretching did not significantly impact markers of muscle damage and inflammation.
The evidence from these studies suggests that static stretching before resistance training and certain exercise regimens may not be the most optimal approach for improving muscle strength and hypertrophy. While stretching has been shown to enhance flexibility, it may have adverse effects on muscle strength, particularly in sedentary individuals and elite athletes. Therefore, athletes and fitness enthusiasts should carefully consider their stretching routines, tailoring them to specific training objectives and exercises to achieve the best outcomes in their fitness journey.