Training for a multi-day ultra

Running multiple races on consecutive days takes specific preparation, says GB international marathon and ultra-runner Holly Rush

Atlantic Coast Challenge

by Holly Rush |

For 2021 I’ve have partnered with the team at Votwo Events (, organisers of the Asics Coast Ultra Xtreme, a five-day ultra event on the stunning Cornish coast. Covering a total distance of 214km with 7400m of vertical ascent and individual stages between 27-60km, the event – held on October 6-10, 2021 – provides a significant but accessible challenge in comparison to other extreme multi-day events such as Marathon des Sables, Dragons Back and UTMB. For the avid ultra-runner, it offers a fast and unique course with four UTMB qualifying points and, for those running at the front, a guaranteed minimum of £2500 in prize money. For the first-timer, it’s tough but achievable. A single overnight site with accommodation or camping on offer, and daily transfers to and from the starts and finishes, provides a comfortable base from which to recover and refuel for the next day.

To help you prepare for this or another event, the Asics Frontrunner Community has plenty of insights and tips needed to successfully complete your first event.

A single day of racing is tough, but imagine running a series of those maximal efforts together for three or more days in a row. This significantly changes the plan, doesn’t it? During a stage race, you can’t just be done with it and go home when you finish for the day. Instead, you’ve got to get up and do it all again in the morning. For instance, the seven-day Marathon des Sables pits the runner against the sand and searing heat of the Sahara, while the Dragons Back takes runners over the mountains of North Wales to South Wales over five days with ascents adding up to twice the height of Everest.

Although each stage race has its own set of specific demands, there are some key universal areas that can be addressed during your preparation.

I’ve been lucky enough to take part in some pretty epic multi-day races all over the world. Here is what I’ve learned that might help you prepare for your next massive-mileage experience, such as the Asics Coast Ultra Xtreme this October.

Ultra-marathon training

Four-plus-day events or races with multiple ultra-legs aren’t for everyone. Many races acknowledge this on their websites by strongly recommending that participants have experience running marathons and in adverse conditions. Ultras compress into a single day the body and mind-bending challenges a multi-day race can present. The benefit of ultra-training includes relatively high training volume, refining an effective raceday fuelling routine, and mentally dealing with long days on the trail –components necessary for a successful multi-day finish. Use the daily distances of the stage race to determine the length of the preparatory ultra. For example, an athlete preparing for a stage race with stages less than a marathon distance should try to complete a marathon to 50k, while those training for events that have marathon and ultra-distance stages, such as the Asics CUX should try to include a 50k distance or more in their preparation.

Back-to-back long runs

Back-to-back long runs have proven effective for athletes preparing for stage races as they mimic amassing stage-race fatigue. This doesn’t always work for everyone and it’s important to not try these straight away, but they certainly give people confidence that they can run on tired legs. For example, I would do a three or four-hour run on the Saturday and a two-hour run on the Sunday. It’s important to practice race fuelling on both these days and space your back-to-back sessions two to three weeks apart to allow for proper recovery. Always progress slowly into these workouts, especially for those inexperienced with high mileage, by starting with relatively short back-to-backs during the pre-season months and building on those as the event approaches.

Training volume and intensity

This obviously depends on the athlete and the event length and distance, but I would recommend this approach... The training for an ultra-runner doesn’t differ much from that of a marathon runner: a long-distance run per week, a speed session per week and as much easy aerobic running as you can fit around your work and life. I would also suggest specifying some of your long runs according to the type of terrain the race will be covering, such as technical climbs and descents. The Coast Ultra Xtreme in Cornwall might not have the same level of elevation or descent difficulty as the Dragons Back, but with 7000m-plus and some technical descents, it will really help to get out and practice your ascending and descending. I would try not to worry about the specific numbers; just try to be as recovered as possible before your main sessions each week. Also, don’t be afraid to cross-train to supplement the aerobic training whilst lessening the impact on your body.

Ultimately, if you get to race day healthy and not over-trained, you have a much greater likelihood of success.


Address race-specific challenges early on in the training block. It goes without saying that terrain and environmental specificity must be accounted for in your training build-up. Acclimatise for heat or altitude. Practice on mountainous/hilly terrain with trekking poles. Run and hike with the exact pack, clothing, and shoes you will wear during the race. Ensure your gear functions properly in the sand, mud, water, and/or snow. Practice walking! This is something we all forget to do... Perhaps the biggest misconception around multi-day stage racing is that the aim is to run the entire way – it’s actually only a very small number of participants who do this (if any).

Strength work and self care

Weeks and weeks of consistent training will accumulate into training stress and fatigue, so in order to manage that you must make sure you develop a consistent self-care routine. This includes rest days, good sleep hygiene, massage/physio and, most importantly, a strength program aimed at strengthening muscles, bones, tendons and ligaments. This will ensure that your body is capable of withstanding the stress placed upon it during a multi-day ultra-race. I would suggest a total body strength programme, especially if using poles, as this distributes the load over the upper and lower body and it’s advantageous to be able to push with both.

Pay very close attention to any issues that pop up during your training so that minor tweaks don’t later develop into chronic problems.

Practising nutrition

It can be very challenging to meet the daily nutritional requirements of running all day. As a rough rule of thumb, the body can burn whilst running between 350-650 calories per hour for someone who weighs around 55kg. Obviously, calories burned per hour depends on weight and level of effort or intensity of exercise so always take any estimates with a pinch of salt. During exercise, it is recommended to consume 30-60 grams of carbohydrates an hour, not because that is how much you need but because that is all the body can process. Eating little and often is key and I try to eat every 45 minutes to an hour when running. It’s a good idea to set an alarm on your watch to remind you to eat. This might sound odd now but it’s very easy to lag behind on your nutrition, and once this happens it’s hard to claw your way back.

It’s also worth considering practising with a variety of foods. Eating and drinking the same stuff every day can be boring and lead to appetite suppression. I like to pack a mix of sweet and savoury as I tend to go off sweet stuff after several hours and instead start to crave salty foods.

Practising eating in training is a key activity and will massively benefit your preparation.

The sections above provide an overview of the approaches to training, kit and nutrition that you will need to consider in preparing for your first multi-day ultra. In the coming issues I will be unpacking kit, nutrition and strength work for your first multi-day ultra in greater depth to help you prepare for success. If you have any specific questions or queries I will try to help with these – just send your questions to

Look forward to seeing you out on the trails and hopefully in October at the Asics Coast Ultra Xtreme. More info on this Cornish multi-day race, visit

Just so you know, whilst we may receive a commission or other compensation from the links on this website, we never allow this to influence product selections - read why you should trust us