Is your goal marathon time realistic?

With 4-8 weeks left before your spring marathon, you’re right in the thick of prime training time. Now is when it becomes pretty common to wonder, “can I really hit the goal time I’m aiming for?” Or, if you haven’t thought about a goal time yet, well, no time like the present!


There’s no way to know for sure what will happen on race day. But there are ways to tell if your goal time is realistic, or if it’s time to make an adjustment before you head into the last couple months of training. Those final weeks of training you should be spending a lot of time running at goal pace, so getting that pace locked in now is key.


Depending on how ambitious your goal time is, the approach to know if it’s realistic will vary:


GOAL: Just PR (even if it’s by a few seconds)


APPROACH: Compare past training to current training


If you goal is to “just” PR, you can use the training you did leading up to your PR race as a good guide to see if you’re on track to improve on that time:


  • Running more mileage than last time?
  • Posting better times in workouts?
  • Long runs going better than last time?


Answering “yes” to any of those questions provides a very good indication that you’re on track to run faster than previous races.


GOAL: Big-time PR — 2-5% improvement
(3 to 9 minutes for a 3-hr marathoner, 6 to 15 minutes for a 5-hr marathoner)


APPROACH: Compare past training + Look at tune-up races


If you’re aiming for something more ambitious, just looking at your training may not be enough to gauge if you’re on track. That’s where checkpoint races become an important part of your training plan.


Racing a half-marathon in the final 3-6 weeks before your marathon is a great way to gauge your current fitness. You can input that time into a race predictor calculator, or use a general guideline of:


Marathon pace = Half-marathon pace +20-30 seconds


That prediction will be more accurate if the half-marathon course is similar to your marathon course in terms of elevation profile, surface, etc. That’s why a half-marathon is more helpful than 10k or 5k races, too — the closer to the race distance, the better the prediction.


And, of course, this assumes that you will be well-trained for your marathon. If your longest long run is 16 miles you might be able to run a great half-marathon but struggle in the later miles of a marathon.


GOAL: MAJOR PR — 5-10% improvement
(9 to 18 minutes for a 3-hr marathoner, 15-30 minutes for a 5-hr marathoner)


APPROACH: Compare past training + Look at tune-up races + Look at your background


When you’re shooting for the stars, everything has to line up just right. You need to step up your game in training, you need checkpoint races along the way that show you’re on track, and you still need more. Generally, it helps to be relatively new to marathons (trained seriously for 3 or less).


If you’ve trained seriously for several marathoners in the past, the odds of an improvement over 5% go down dramatically. It’s always easiest to drop time when you’re just starting out, and that is true for the marathon, too.


If you’re a veteran marathoner who was well-trained in the past and you’re looking to make a big leap, I think it’s still possible if you’ve got some other factors working in your favor:


  • You made significant changes to your training program, mileage, etc.
  • Dealt with injuries in the past and now have put together several injury-free training cycles
  • Significant weight loss
  • Favorable course / weather compared to previous marathons
  • Lifestyle change that allows for more training / recovery time


If none of those factors are in play, I think it makes more sense to aim for 5% improvement now and 5% in your next training cycle rather than count on 10% improvement in one race.


About Coach Carl
Coach Carl is a USA Track & Field Level 2 endurance coach who works with runners of all ability levels to reach their goals. He has been featured in Runner’s World, Women’s Health, and Competitor and is a regular contributor to Running Times.