My advice is to take time off in order to get acclimated before the marathon. To arrive one week before the start will be enough to get acclimated successfully. If you have extra time and willingness, you can climb Mount Elbrus, in addition to your race trip. You may relax after the race for 3 days and then you are ready to climb. But you need to remember about your safety and climb with a reputable guide or a group of skilled friends. Speaking of outfit, the list of necessary equipment given by organizers is not to be neglected. I came to it from my own experience. I have been participating in EWR for 3 years and weather conditions were different each year. In 2016 and 2017 the weather was hot, therefore I didn’t need all the equipment from my backpack. However, in 2018 the weather went bad. At the pass we faced wind and rain, so most of participants needed almost all the equipment they had. So an equipment list can be very useful. Moreover, good-quality equipment is lightweight and long-lasting.
The Marathon distance is a 46-kilometer route that consists of the Trail distance (34 km) plus one more loop. The distance is technically challenging because of the rocks, that is why you will definitely need good running shoes with foot support.
Turning to trekking poles, unlike the second time, I didn’t use them when I was passing the distance for the first time. Trekking poles can be very useful when you start climbing, however, when you go through the stone loose, you better put them to your backpack or at least make them shorter, otherwise they can be bothering or even break. On the way down you should use trekking poles only if you are skilled enough, in that case you better practice beforehand. You will need trekking poles again when you start climbing up the second slope, it’s very steep and rocky as well as the way down. You should be careful on the path after the descent, it’s very rocky, you can easily stumble.
By the way, the second climb way stretches along the river where you can freshen up and take on water. I suggest using soft flasks instead of hydration reservoirs, because they are more convenient. Pay attention to feeding stations marked on the map in order to distribute your food stocks appropriately. Don’t forget to plan a convenient access to food and water, decide where to put each thing. To participate in the Marathon, you need to have good balance and coordination skills, and your back, leg and ab muscles should be strong as well. If your muscles are not strong enough, the strain puts on your joints. My advice is to train with a balance board and to try slacklining during your preparation for the race. Also wearing a stretch tape can be very useful while racing.