Welcome to the first 8 weeks of your 24 week marathon plan.
This plan is meant for athletes that are time constrained. The heavy intensity of the workouts are meant to replace the workouts that you would normally do in a higher volume plan.
If your marathon is less than 24 weeks away, you should still start with this plan.
When you are finished with this plan, you should advance to the "The Workday Grind - Build Phase", which is another 8 weeks of training: https://www.trainingpeaks.com/my-training-plans/Low-Volume-Build-Plan
The final block of training is the "Race Specific Low-Volume Marathon Plan" (8 weeks). This is meant to build fitness and experience specific to your race goals, and taper you so that you're properly rested for race-day. This is only meant for athletes that have finished the initial 16 weeks of the marathon plan.
NOTE: Although heavy intensity workouts result in quick and significant gains, they can and often do result in injury. This is why it's important to NOT skip the lifting workouts of this plan. The lifting is specifically designed for injury prevention as well as performance enhancement.