If you run and enjoy improving your times or 'having a good time', probably you've already wondered 'how fast can I handle my marathon / half marathon / 10km'?
The answer is far from obvious. It depends among other things on your aerobic capacity, of your endurance level et of your running economy. Since it is difficult for amateur athletes to isolate these different variables, I often suggest using recent running results to assess your current ability.
These are often called preparatory competitions. These competitions can be used in two ways:
Running the given distance as fast as possible
When choosing this approach, you should select an event that is approximately half the distance you are preparing for. Then you prepare for this event as if it were your final competition. You take the opportunity to test bedtime, diet, equipment, etc. On the other hand, on race day, instead of going to the limit and giving your 100%, you limit yourself to giving 99% of your maximum performance. This will allow you to recover much faster.
Then you can use the McMillan calculator to compare the result of your test (current fitness level) with the level you would need to accomplish your goal (your goal).
This will help you see if your goal is realistic.
Generally, I suggest doing this test 3-8 weeks before your primary goal. The longer the distance, the more you should test yourself in advance. For example, if you are preparing for the Quebec City Marathon, you could come and prepare for the Challenge of the Cité-Limoilou.
As a long workout
The other way to test yourself is to do a long workout, with a portion at the pace you want to keep on your longer distances. Usually it is easier to do this type of training in a formal event. Here are some typical sessions you could do:
In preparation for a 10 km: 4 km warm-up, then 5 km at the target pace for your 10 km, then 4 km to calm down.
In preparation for a half-marathon: 7 km warm-up, then 10 km at the target pace for your 10 km, then 3 to 5 km to calm down.
In preparation for a marathon: 7 km warm-up, then 21,1 km at target pace, then 3 km to calm down.
Please note, these training sessions require a good training baggage over the chosen distance. If this is your first time doing your chosen distance, I suggest that you instead focus on covering the distance rather than testing yourself for the exact pace you can achieve.
Good preparation and good challenge!