In 2000, DePino, et. al., conducted study about Muscle flexibility which is a crucial aspect of overall mobility and physical performance. Static stretching has long been acknowledged for its potential to improve muscle flexibility. While various studies have highlighted the immediate benefits of static stretching, there is a gap in our understanding regarding how long these flexibility gains persist, especially after same-day stretching. In this study, we aimed to assess the duration of enhanced hamstring flexibility resulting from an acute static stretching protocol, specifically focusing on knee joint range of motion.
A group of thirty male participants with limited hamstring flexibility in their right lower extremity took part in this investigation. Their average age was 19.8 years, with an average height of 179.4 cm and weight of 78.5 kg. The participants were randomly assigned to either the control or experimental group.
The study involved a pre-established warm-up routine of six active knee extensions, with the final repetition serving as a baseline measurement. Subsequently, the experimental group executed four static stretches, each held for 30 seconds and interspersed with 15-second rest intervals.
Post-exercise measurements of active knee-extension range of motion were taken from both the control and experimental groups at various time intervals: 1, 3, 6, 9, 15, and 30 minutes after completing the stretching routine.
A detailed analysis using Tukey’s post hoc method indicated a significant improvement in knee-extension range of motion among participants in the experimental group. However, this improvement was found to last only for a duration of 3 minutes after the cessation of the static stretching protocol. Subsequent measurements taken beyond the 3-minute mark did not display any statistically significant differences compared to the baseline measurements. Furthermore, a dependent t-test revealed a noteworthy increase in knee-extension range of motion when comparing the first active warm-up repetition to the sixth repetition, suggesting an overall positive impact of the warm-up routine.
The findings from this study underscore the potential benefits of a series of four consecutive 30-second static stretches in enhancing hamstring flexibility, as evidenced by an increased knee-extension range of motion. However, the notable increase in flexibility was short-lived, lasting only 3 minutes after the conclusion of the stretching regimen. This investigation sheds light on the need for further research to explore alternative stretching techniques that can potentially yield more enduring flexibility gains on the same day. Understanding the temporal aspects of flexibility enhancements can aid athletes, fitness enthusiasts, and healthcare professionals in optimizing stretching protocols to suit their specific requirements.
Reference: DePino, G. M., Webright, W. G., & Arnold, B. L. (2000). Duration of maintained hamstring flexibility after cessation of an acute static stretching protocol. Journal of athletic training, 35(1), 56.