Should stretching be a part of a warm-up?

Warm-ups, which increase blood flow into the involved muscles and elevate muscular temperature, are performed for 5 to 15 min before engaging in the main exercise. Performing warm-ups can lower the risk of injuries in the muscles and tendons, as well as reduce heavy loads on the heart, which can occur when high-intensity exercises are suddenly starting. Stretching increases the range of motion of the joints and is effective for the maintenance and enhancement of exercise performance and flexibility, as well as for injury prevention. However, stretching as a warm-up activity may temporarily decrease muscle strength, muscle power, and exercise performance. Whether or not stretching was included in warm-ups performed by nonathletes before participating in recreational sports activities, no significant differences were found in regards to exercise performance. Warm-ups appear to provide psychological and physiological preparation for exercise performance. Although warm-ups did not have a statistically significant effect on the variables of physiological aspect, they seem to have a meaningful effect on athletic performance by affording psychological stability, preparation, and confidence in exercise performance.

Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5833972/