This plan provides an 8-week focus on lactate threshold training for runners with at least four years of training experience who are targeting an event from 50K to 50 miles.

The plan holds training volume relatively constant while focusing on intervals at or below your lactate threshold. The purpose of this training phase is to raise your lactate threshold by improving lactate tolerance and decreasing lactate accumulation, which allows you to stay aerobic at faster speeds.

The plan is part of the Alp Fitness ultra running series designed to take you through a progression of training phases over a period of about six months to prepare you for your ultramarathon. The recommended progression through the series: Aerobic Base Conditioning (optional) > VO2max Training (4 weeks) > Lactate Threshold Training (8 weeks) > Endurance Training (12 weeks) > Taper (2 weeks).

The plan integrates mental skills training into your running workouts, and includes a strength training program to supplement the run training.

Begin this plan about 22 weeks out from your target event and follow it with the endurance training plan to help you build volume for your goal event. Before beginning this plan, it is recommended that you’ve completed the VO2max training plan — or the equivalent in training.

The plan assigns running volume based on training hours and training stress score (TSS). Adjust the frequency, volume, and number of intervals up or down based on your personal starting point — see the guidelines within the plan to customize the plan for your own situation.

To target and monitor your training intensity, the workouts provide training zone descriptions based on breathing and talking cues to help you gauge your perceived exertion, as well as heart rate ranges, if you use a heart rate monitor. The Alp Fitness training zones are also compatible with running power. But you are encouraged to learn to judge your effort levels "by feel" even if using these other tools.

No matter where you want to go, you must start where you are with your own unique goals in mind. This plan — like any training plan — represents an initial draft, rather than a final document set in stone. You will write the final version over the coming weeks as you glean feedback from your training and adapt the plan to your specific situation and goals. Train smart!