With less than a week until you hit the Philadelphia Marathon starting line, it’s time to get serious about your race strategy.

On race day, pacing yourself correctly is likely the single greatest factor you can control. By demonstrating patience and discipline (more on that essential skill here) throughout the first two-thirds of the distance, you set yourself up for an awesome finishing stretch where you’re the one passing other runners. You’d like that, wouldn’t you?

To help runners nail this difficult task, many races like the Philadelphia Marathon and Half Marathon offer an enticing option to run with a pace group. This is where an experienced runner will help other runners reach the finish line at popular goal times, usually every 10 or 15 minutes starting close to the three-hour mark.

The pace leader typically carries a stick with balloons so that they’re easy to spot on the course. Often these pacers are very positive, motivating individuals.

Are pace groups right for you? Here are a few things to consider:

What kind of runner are you?

Do you tend to focus inward and block out others so you can concentrate and do your thing? Or are you more social and thrive on the energy of a group?

I know some runners who feel claustrophobic while running in a pack; they're constantly worried about tripping or chaos at each aid station. Yet others harness the power of the pack and find that placing their trust in the pace leader allows them to not worry about pace.

Does your pace match?

Usually you can find a group running a pace that closely matches yours, but sometimes your smartest pace happens to be between two groups. For example, you've trained to run a 4:10, but only 4:00 and 4:15 groups are offered.

If you really want to run with a group but still reach your time goal, then start with the slower group and leave them at some point after the halfway mark, once you're confident you can maintain the pace through the finish.

Beware, pace groups can be hit or miss

Sadly, pace group leaders aren't robots – because it would be fun to run with robots! – and not all have a wealth of experience.

Ideally, you'd want to meet the group leader ahead of time and ask them how many times they've been a pacer and what their best time is. I'd even ask them what their pacing plan is to see if I'm a match.

Watch out for pacers who have a significantly faster PR than the pace group they're leading. Frequently, these folks aren't as in tune with the rhythm or mechanics of that pace and will unconsciously speed up. Even if they slow down to compensate, it's inefficient to change paces during a marathon and ideal to run a more even tempo.

Once, I had a client who stuck with the 3:05 pace group and the leader brought them through halfway on 2:57 pace. This was way too fast. My client's mistake was to blindly follow the leader and ignore his keen sense of pace he'd spent so much effort developing in training. Next time, we agreed, he'd just trust himself.

At the end of the day, you're the one in control and you should be prepared to do your own thing if necessary. You can always speed up or drop behind the group, whichever works best for you!

John Goldthorp is the founder of Fix Your Run, a specialized fitness coaching business in Philadelphia that helps runners become faster and less prone to injury.