Research has shown that foam rolling before your workout can increase range of motion without the decrease in muscle power that can result from pre-workout static stretching.
Using a foam roller to achieve improved range of motion allows you to become stronger in that extended range. For example, if you are working on doing deep squats, foam rolling will facilitate a deeper squat thereby allowing improved engagement and strengthening of your glutes. So, if you are strength training as part of your half-marathon prep, you should be able to improve your time.
You can have postural imbalances caused by tight muscles and fascia. By releasing the right muscles and fascia with myofascial release you can help to correct these postural imbalances.
Foam rolling can also stimulate the lymphatic system and help to reduce fluid retention. This effect is short lived but by reducing a bloated appearance and dimpling in the skin, rolling will have you looking leaner for at least a couple of hours.
Read the full article here: https://www.thesocial.ca/wellness/fitness/2018/april/get-your-legs-looking-long-and-lean-for-summer