Is pre-run stretching of the hamstring muscles beneficial?

From the Guidelines

Stretching hamstrings before a run is not recommended as it can temporarily reduce muscle power and may not prevent injuries as once thought. According to the most recent study on returning to running following a tibial bone stress injury, a scoping review published in 2024 in the journal Sports Medicine 1, the focus should be on strengthening and flexibility exercises, including calf stretching and hip strength, rather than static hamstring stretches before running.

When considering a pre-run routine, it's essential to prioritize dynamic stretching or a light jog to increase blood flow, raise muscle temperature, and prepare the neuromuscular system for activity. Some key components of a pre-run routine include:

• 5-10 minutes of light aerobic activity, such as walking or easy jogging
• Dynamic movements like leg swings, high knees, or butt kicks to gradually activate the muscles used while running
• Saving static hamstring stretches for after the run when the muscles are warm and more pliable, holding each stretch for 20-30 seconds without bouncing

This approach is supported by the study's recommendations for flexibility exercises, including calf stretching and hamstring stretching, but emphasizes the importance of timing and type of stretch 1. By focusing on dynamic stretching and saving static stretches for after the run, individuals can help maintain muscle elasticity and improve recovery, ultimately reducing the risk of complications and improving overall running performance.

From the Research

Effects of Stretching on Hamstring Injuries

• Hamstring injuries are a common issue in sports, and stretching is often used as a preventive measure 2, 3, 4, 5, 6.
• Research suggests that static stretching (SS) and dynamic stretching (DS) have different effects on hamstring flexibility and stiffness 2.
• A study found that multiple bouts of SS were superior to DS in improving hamstring range of motion (ROM) in the acute and sub-acute effects, but there was no significant difference in the medium-term effect between the two stretching techniques 2.
• Another study found that short-duration SS (≤60 s per muscle group) trivially impairs subsequent strength and power activities, while longer SS durations (>60 s per muscle group) appear to induce substantial declines in strength and power performances 3.
• Chronic effects of static and dynamic stretching on hamstrings eccentric strength and functional performance found that static stretching training reduced eccentric torque and functional performance 4.
• A review of rehabilitation strategies for hamstring injuries found limited evidence to support the use of stretching exercises, but suggested that exercise to correct movement dysfunction could reduce time to return to full activity and the risk of re-injury 5.
• A review of injury prevention programs found that exercise interventions, such as eccentric strength training and Nordic hamstring exercises, can be effective in reducing the incidence of hamstring injuries 6.

Key Findings

• Static stretching can improve hamstring ROM, but may have negative effects on eccentric strength and functional performance 2, 4.
• Dynamic stretching may be more effective than static stretching in improving hamstring length and reducing stiffness 2.
• Short-duration static stretching may be beneficial for flexibility and musculotendinous injury prevention, but longer durations may have negative effects on strength and power 3.
• Exercise interventions, such as eccentric strength training and Nordic hamstring exercises, can be effective in reducing the incidence of hamstring injuries 6.