If you're looking to get faster you need to be doing interval work. This could be 10x 400m, 8 x 800m, or anything that allows you to push close to lactate threshold. Running paces faster than your goal race pace is the best way to have this pace feel more comfortable. For example my race pace is 6:05, which is why I'm doing all sets at around 5:20 pace. If you'd like me to build you a speed workout, please let me know!