PHASE 2: THRESHOLD RUNS

In my pre­vi­ous arti­cle I dis­cussed the the con­cept and ben­e­fits of build­ing a strong foun­da­tion while incor­po­rat­ing some short higher inten­sity seg­ments (strides/hill sprints.) Once you have estab­lished a strong foun­da­tion and are close to your max­i­mum weekly mileage it is time to add a weekly thresh­old or high aer­o­bic run into your train­ing. Thresh­old runs are some­times referred to as tempo runs although the term “tempo” is often used loosely.
Thresh­old runs are a great way to boost fit­ness with a rel­a­tively low stress fac­tor on the body com­pared to more stress­ful work­outs such as inter­vals. This means the risk of over­train­ing and injury is sig­nif­i­cantly less. For half marathons and marathons I feel thresh­old runs pro­vide the most bang for your buck and should be a sta­ple in your train­ing fol­low­ing your foun­da­tion build­ing phase.
Thresh­old pace cor­re­lates to a pace where blood lac­tate lev­els are ele­vated but steady. What does that mean? For the large major­ity of run­ners this is the max­i­mum pace one can hold for about an hour. For an elite run­ner this is likely close to half marathon pace while for a recre­ational run­ner (who may not have the best genet­ics) this is likely closer to 10K pace. For most of us it is close to our 15K race pace. If you train with a heart rate mon­i­tor this is typ­i­cally between 88% and 92% of max­i­mum heart rate. To read more on Max­i­mum Heart Rate … See Below.

MAXIMUM HEART RATE

There are var­i­ous meth­ods to esti­mate max­i­mum heart rate, some more accu­rate than oth­ers.
The most widely used, and basic, method to find your max­i­mum heart rate is to sub­tract your age from 220. How­ever, there can be sig­nif­i­cant vari­ance using this method. There are other “cal­cu­la­tions” that are typ­i­cally more accu­rate, but below I am going to sug­gest a cou­ple “field tests.” Make sure you are prop­erly warmed up before you begin.

If you run a 5K race all-out you should hit, or be close to max heart rate by the end, assum­ing you are, indeed, going all out. Another method is to run 5 one minute (steep) hill sprints (or repeats) in suc­ces­sion, with 30 sec­onds recov­ery in between each repeat. Run the first one at 80% effort. The 2nd at 90% effort. The 3rd, 4th, and 5th at 100% effort. You should be very close to your max­i­mum heart rate on your 4th or 5th repeat.
If you are going to use a heart rate mon­i­tor make sure you know why you are using it and what to do with the data. Most of my ath­letes (includ­ing the fast ones) do not wear heart rate mon­i­tors pri­mar­ily because it does not fit their per­son­al­ity and they like to run more based on effort or pace.

There are many ways to struc­ture a thresh­old run but we are going to pro­vide two sim­ple exam­ples below. Make sure the Easy por­tion is indeed easy. WIth the ath­letes I coach I typ­i­cally use paces from the pace cal­cu­la­tor at www.McMillanRunning.com (You input a recent race time and the cal­cu­la­tor tells you what your esti­mated paces at var­i­ous efforts should be based on physi­co­log­i­cal test­ing.) You can build up to a max­i­mum of 30 min­utes at thresh­old pace or you can break it into two sets like we do in exam­ple 2.

Exam­ple 1

30 min­utes Easy
20 min­utes Thresh­old Pace.
15 min­utes Easy

Exam­ple 2

30 min­utes Easy
15 min­utes Thresh­old Pace
10 min­utes Easy
15 min­utes Thresh­old Pace
15 min­utes Easy Running.

Your thresh­old pace should get faster as you com­plete more runs at this pace. This will pro­vide huge ben­e­fits for your next half marathon.