How to prepare for your first marathon: A beginner’s guide
It’s the ultimate goal for many runners. A legendary distance. The marathon attracts millions of runners worldwide, whether they are beginners or elite athletes. While some aim to break world records, others simply hope to finish. Regardless of the goal, the marathon has become extremely popular. However, running (and finishing) a marathon remains a significant athletic challenge. The effort can be daunting, and the distance should be approached with humility. So, if this season, your goal is to run your first marathon, here’s a guide to accompany you throughout your preparation, all the way to the finish line. Ready? Go!
Why Run a Marathon?
It’s the legendary distance in running, and running enthusiasts want to give it a try. Isn’t the marathon, alongside the 100m final, the most anticipated event in athletics? One crowns the most enduring person, the other, the fastest. But why is the marathon distance so legendary? You’ve probably heard about the Athenian soldier and messenger named Pheidippides. According to legend, he ran nonstop for 40 km to Athens to announce the victory at the famous Battle of Marathon. Pheidippides would be the first marathoner. At Marathons.com, we’ve explored the why and how of these 42.195 km.
Runners always crave more. It often starts with a simple 10 km for fun with friends, but it never stops there. “If I can run a 10 km, I can run a half marathon. If I can run a half marathon…” You know how it goes, we do too.
Being a marathon finisher is a source of pride for many runners, and rightly so. Whether it’s sharing experiences with friends, personal challenges, supporting a cause, or self-improvement, every marathoner has their reasons for running a marathon.

Planning and Goal Setting
Before discussing training, nutrition, and race day, let’s talk about goals. Depending on your running level, race experience, and desires, your goal and preparation for your first marathon will vary. Explanation: you already have substantial experience with a half marathon (several races under your belt) and want to tackle a marathon. You can clearly aim for a time goal based on your half marathon reference. On the other hand, if your running experience needs to be solidified, your goal is likely to finish your marathon without focusing on time. You might also simply decide to enjoy and discover the distance. Remember, it’s important to define your goal for your first marathon. It will directly impact your preparation and the choice of your marathon.
It might seem obvious, but deciding to run a marathon isn’t something to choose overnight. Although… we all know a runner who’s tried it. The preparation lasts at least 3 months. Again, each preparation is individual. It depends on the runner’s level and experience. Opt for a marathon at least three months away; this marathon calendar might interest you. Keep in mind, the longer your preparation, the more time you have to build a solid base, add preparatory races, and be ready on race day.
Training Program for marathon preparation
Did you run your first 10k or half marathon without preparation? Don’t count on doing that for a marathon. At least, that’s our advice. Worried about the distance? It’s normal. There’s nothing trivial about running a marathon. To have a unique experience on your first and fully enjoy your race, nothing beats good preparation. Various coaching solutions are available: a personal coach, training at a club, a coaching app, training alone… Decide which solution fits your profile best.
Building Endurance
Importantly, adapt our advice based on your level, experience, and goal. To prepare for such a long race (yes, 42.195 km is quite something), you need a solid running base. How is a marathon training plan structured? The core work is on endurance. 80% of the weekly training volume is dedicated to endurance work, meaning running at low intensity. The remaining 20% is for speed, hills, or specific pace work. Working on endurance improves the cardiovascular system and gets your body used to a higher training volume. Paradoxically, running slowly helps you run fast.
Working on Marathon-Specific Pace
“Spec session”, “marathon pace” – you’ve likely seen these terms in various blog posts or marathon training plans without quite knowing what they mean. Simply put, your specific pace is your race pace. The speed at which you’ll run your marathon. In marathon preparation, there are specific sessions to get you accustomed to race pace and train you to maintain it over several kilometers. These are intense sessions where your heart rate and muscles are severely tested. They’re less frequent than regular runs.
Strengthening the Body
For a comprehensive marathon preparation, don’t neglect physical preparation, also known as strength training. Why? Remember, you’re going to run 42.195 km, which requires significant work from your muscles, tendons, and joints. During your preparation, you’ll run several times a week and rack up kilometers. It’s essential to strengthen yourself to handle the distance and reduce the risk of injury.
Calculating Different Paces
How do you know your training paces? It’s a good question. If you have one or more references from a half marathon, you can project a time for a marathon. Your race pace can be easily calculated based on your target time. However, if you lack data, don’t panic. We recommend doing a simple test to calculate your maximum aerobic speed (MAS). This test involves running as far as you can in 6 minutes.
Example: You covered 1,400 meters in 6 minutes. Multiply 1,400 by 10, giving you 14 km/h. From this data, you can calculate all your paces. You can choose shorter preparatory races than a marathon to include in your program. Many runners do a 10k or a half marathon a month before their marathon. You can aim for a record on the distance or run at marathon pace to get used to the speed.

Nutrition and hydration: The basics
Start with the assumption that you’ll be running for at least 2 hours. Even the current world record holder for the marathon doesn’t go under 2 hours. Nutrition and hydration will be two factors that directly impact your race. Simply put, think of a car. To move, it needs an engine. The engine needs fuel to work. For runners, it’s the same. The engine (cardiovascular system, muscular system, etc.) needs energy to function. Carbohydrates provide this energy. It’s essential to have energy before the race and to replenish losses during the race.
Nutrition and hydration before a marathon
Before you continue scrolling, remember this golden rule: never try new things on race day. Let’s be honest, the healthier, varied, and balanced your diet is during preparation, the better. However, the most crucial time for good nutrition is the week before the race. You need to provide your body with the necessary resources before even starting. Considering hydration, it’s advised to drink at least 2 liters of water per day and avoid sugary drinks. Regarding nutrition, here are a few tips to stay in shape and avoid gastric issues:
- Avoid alcohol
- Choose quality foods with a low glycemic index (brown rice, quinoa, sweet potatoes, buckwheat, honey, and agave syrup…)
- Avoid fibers and raw vegetables that may not be well tolerated
- Limit high glycemic index foods: white pasta, white bread, sugar, fried foods…
Nutrition and hydration on race day
Marathons generally start in the morning. Breakfast is the only meal a few hours before the race. To avoid digestion problems, it’s advised to have the last meal (usually breakfast) 3 hours before the start. Continue to hydrate well (0.5 liters per hour) until race start. You can also plan a waiting drink to consume between breakfast and the start. For breakfast, some prefer sweet, others salty. It’s based on your habits. Some foods to avoid right before a race: sodas or fruit juices, high-fiber foods like whole-grain bread, and dairy products.
And during the race? Let’s keep it simple and effective even if the subject could fill several pages. You’ll consume a lot of energy as the kilometers pass. You’ll need to replace these losses with carbohydrate and water intake. The goal is to find a balance to provide enough energy to your body without causing intestinal issues. Carbohydrates can be found in gels, sports drinks, bars, or purees. Each has its pros and cons, and it’s up to you to find your own recipe. That’s why we recommend testing your nutrition strategy during training to avoid unpleasant surprises on race day.
Getting the right gear for the marathon
Gear won’t make you a good runner, but it will make your effort more comfortable and reduce the risk of injury. To be clear, the gear list for a marathon will be much lighter than an ultra runner heading for 24 hours in the mountains. A pair of socks and running shoes, shorts, a shirt, and four pins are the essentials. Add to that a cap and sunglasses, a GPS watch to track your pace or see how many kilometers left to run. In cooler weather, arm warmers, small gloves, and a neck gaiter won’t be too much. Finally, to carry your personal nutrition supplies, a belt or bottle holder. Your race gear is complete.
Remember you might have to wait several minutes at the start line and it’s better to keep your muscles warm after warming up. Tracksuit bottoms, tights, and a jacket are advised while waiting.
Same golden rule as for nutrition: don’t try anything new on race day, even the new socks you bought at the event expo. You might regret the blisters after 20 kilometers. Use your long preparation period to test all your gear during training.
The final week before the race
The final week before a marathon is like the days leading up to Christmas: you prepare everything carefully without giving in to excitement (or stress). Training-wise, you eased up a week ago; you’re in the peak phase. This means the training volume has decreased, but you continue to maintain some quality work. This process allows you to arrive at the race with optimal freshness. If you’ve skipped sessions, there’s no need to cram them into the last week, as you risk exhausting yourself before the race. As for nutrition, as mentioned earlier, prioritize quality carbs. Sleep is an important component right before your race. Make it a priority to recharge your batteries. Use this lighter training week to finalize logistical details.
- How will I get to the race?
- Where should I park?
- When and where can I pick up my bib?
- Do I have all my gear and nutrition supplies?
- Are my pacing times ready?
- Which starting corral am I in?
Race day
The most awaited day of your preparation: race day. Sometimes, trying too hard can lead to small mistakes. In the morning, set an alarm early enough to have breakfast 3 hours before the race. Then, put on the outfit you’ve tested and approved. Remember: it’s a marathon, not a fashion show, so stick to your tried-and-true favorites. Plan to arrive with a bit of time to spare on-site, but not too early. Waiting in the cold for an hour isn’t the best strategy. Take the time to warm up properly before entering your starting corral. It’s time to remember all your preparation and enjoy the moment. Don’t forget, it’s your first marathon, and you can be proud to be at this starting line. Once the race starts, stick to your planned pace, even if the urge to sprint like Usain Bolt tickles you. Remember, it’s 42 kilometers. Above all, enjoy it! Smile at the supporters, savor the cheers (even if the “Go Mimi!” sign isn’t for you). Save some energy for the final stretch and a smile for the photographers.
Recovery and reflection
You’ve ticked off the “Marathon” box – congratulations! Yes, you can brag at the coffee machine on Monday morning. Because even though there were many runners at the race start, remember this figure: according to a study by RunRepeat, about 1.3 million people ran a marathon in a given year. That represents only 0.01% of the world population.
A few hours after your race, another marathon begins… recovery. You’ll need several days to regenerate, and that’s normal. Keep hydrating well and treat yourself to a nice post-race meal. Accept that going down stairs might feel like an Olympic event.
Reflect on your first marathon experience. Consider how it benefited you as an athlete and as a person. Assess how much you enjoyed this marathon project. Take some time to think about what’s next; you might decide to go for another marathon to beat your record. Yes, it’s quite addictive!
This time, you have all the information you need to prepare for your first marathon thanks to this beginner’s guide. Running a marathon is a great sporting challenge, congratulations on this goal. Remember, preparation for such an event is essential, but also personal. Find your perfect recipe to be ready on race day. Here’s some inspiration to find your next marathon, and if you want to stay in France, we’ve discovered the best marathons in the country. Happy training!