For casual long distance runs, this is typically true, but not for a road race.

Although it depends on the total distance, for most competitions, it's often good to start fast (at least for the first few seconds or meters) to secure a good position. Studies have shown this initial burst will not impact your overall race. Even though you end up running the same pace as other runners, you'll be way ahead of them.

For the rest of the race, it's generally best to maintain an even, consistent pace slightly above what you're used to during training. If you do it correctly, you should not have much energy left at the end of the race. Some professional runners also speed up around turns to pass other runners. Note, sometimes it feels like you're running faster toward the end even though you're maintaining the same pace because you're tired.

This type of control can be achieved through proper training. In addition to building endurance, training should include timed intervals and speed work. Use a stop-watch, try to run outdoors whenever possible, and take advantage local tracks.