See how foam rolling was shown to improve blood flow to targeted muscles for an extended amount of time, and the implications for warm-up and cool down benefits.
Hotfiel, T., Swoboda, B., Krinner, S., Grim, C., Engelhardt, M., Uder, M., & Heiss, R.U. (2017). Acute effects of lateral thigh foam rolling on arterial tissue perfusion determined by spectral Doppler and power Doppler ultrasound. Journal of Strength and Conditioning Research, 31(4), 893-900.
Purpose of the study:
The purpose of this study was to assess the impact of foam rolling on arterial blood flow and tissue perfusion by spectral Doppler and power Doppler ultrasound. The researchers hypothesized that foam rolling would increase local arterial blood flow directly after rolling, but the changes would last for less than 30 minutes.
21 healthy, uninjured subjects (12 male and 9 female) participated in the study. All subjects had more than 3 months experience with foam rolling. Additionally, all subjects had normal blood pressure and no chronic diseases.
Procedure or Methods:
All 21 participants received spectral and power Doppler ultrasounds from an initial resting condition. Participants were re-examined directly after and 30-minutes after foam rolling.
The foam rolling protocol consisted of 3 sets of 45-seconds each of foam rolling the lateral thigh (IT band). 20-seconds rest was allowed between each set. Participants rolled from the lateral tibial condyle upward to a position superior to the greater trochanter and back to the starting position. Foam rolling occurred at a constant velocity (as much as possible) of 1 rolling per 2-seconds. The intervention was controlled by a physical therapist.
Improvements in arterial blood flow of the lateral thigh were measured both immediately after foam rolling and 30-minutes later.
This study found that arterial blood flow of the lateral thigh increased directly after and 30-minutes after foam rolling in comparison to resting conditions. Absolute blood flow (Vmax) improvements measured directly after foam rolling corresponded to a relative increase of almost 74%. After 30-minutes a statistically significant increase in tissue circulation was still measured, with absolute blood flow corresponding to a 53% relative increase.
The authors suggest that these findings contribute to the ongoing discussion and understanding of local physiological reactions of foam rolling. The advantages of the enhanced blood flow may be important for warm-up and recovery. The results of this study support the use of foam rolling in physical activity if enhanced tissue circulation is required.
Take away for NASM-CPTs:
This study found that blood flow of the lateral thigh increases significantly after foam rolling in healthy participants. These findings indicate that foam rolling is a valuable part of an integrated dynamic warm-up as blood flow is of importance to reduce the chance of injury. Increases in circulation lasted for up to 30-minutes. Additionally, foam rolling as part of a cool down is also supported. While muscle soreness from a workout is largely contributed to the microtrauma that the muscle fibers sustain, recovery may be sped up by actively encouraging the metabolic waste out of the working muscle.
*It should be noted that this study did not include any measures of movement performance, flexibility, or range-of-motion. Thus, the data is generalized to blood flow in the lateral thigh. However, with improvements being recognized locally it is likely that increases in circulation will be experienced in any muscle group receiving foam rolling or self-myofascial release.