Running a marathon is not a decision you can make on a whim. It's not like you can whack on a bib at the last minute and just see what happens.
It involves months of preparation in terms of both training and nutrition, and if you don't know what you're doing, don't expect for everything to 'be okay on the day.'
In order to get you race ready, HuffPost Australia spoke to the experts. Here's what they had to say.
How long do I need to prepare for?
"You need to give yourself months of preparation. I would recommend for a first timer, at minimum, four months of training preparation," former NRL player turned endurance runner Ben Lucas told HuffPost Australia.
"The second part to that point is you need a plan for that.
"That's actually one of the things I love love love about marathon running. If someone has a healthy body, I can get anyone to cross the line on a 42.2km run if you just stick to the plan.
"You need a proper periodised plan to hit that goal. It's not just running as hard as you can every time. There is going to be hills, intervals, there are going to be slower runners. You need months of preparation and you need a detailed periodised plan to help you [navigate] that."
How to train for a marathon
Obviously you'll need to be running, but that should be just one component out of your overall strategy, and to focus on it exclusively would be a mistake.
"Other things you need in your plan is strength work," Lucas said.
"It's not just running. It's a combination of the running, core and strength work. You need to sleep more. you need to up your hydration.
"Probably one of the biggest battles of the marathon is getting to the start line healthy. Where most people get it wrong is they do all their running work but don't do their recovery work which is stretching, yoga, massage, increased sleep, nutrition and hydration.
"It's not just about the training. It's about helping your body recover to train better, mainly focusing on your core and legs and glutes."
Lucas also recommends taking the time to get fitted properly for running shoes.
"Have a look at the gear you are wearing," he said. "You need to train in the right shoes for your body. Equipment is often under looked.
"Don't get the best shoes for aesthetics. Get them for your your body. Do you roll in or out? Do you have flat feet or a high arch?
"I would highly recommend going to a specific running shop and getting fitted out for their best shoe."
Finally, Lucas warns against the temptation of over-training in the weeks leading up to the event.
"One week out, guess what, you're not going to get any fitter, stronger, faster," he said.
"One week out you want to be really looking after your body, really focusing on sleep, stretching, nutrition.
"You are going to be a bit itchy, you're going to want to be out there flogging yourself, but all the hard work is done.
"You can't get any fitter in the last two weeks and it's much better coming in feeling fresh.
"In the last week I'd do two to three shorter, quicker runs of 25 to 30 minutes, max. I'd be upping my carb levels and hydration, focusing on sleep and stretching, and really aiming to come into race day feeling bang on."
What's the best way to recover after training?
According to Lucas, there's no 'best way', just as long as you're doing something.
"It comes down to what people like," he said. "I use a float tank. There are a number of different ways. Some might be sleep. It could be active recovery, like going for a gentle walk or swim or ride. Yoga, Pilates. Just some non-impact movement that gets the blood flowing."
Nutritionist Moodi Dennaoui (aka the Diet Doctor) also stressed the importance of recovery, especially as you draw closer to race day.
"Focus on the recovery component," he told HuffPost Australia. "In the weeks leading up, the more relaxed your musculoskeletal system is, the better.
"I'd be focusing on massage therapy, foam rolling, stretching, warming up correctly... all the things that could potentially prevent you from performing on the day.
"The last thing you want is to run really intensely for a couple of weeks and then realise that you're too tired or exhausted for the event that really matters.
"On that note, I'd say you'd want to train at 70 to 80 percent maximum capacity. You never want to go 100. you want to save it for the day that counts."
In terms of what to eat after a bout of training, Dennaoui recommended "a fast digesting protein, a whey protein".
What should I eat before a marathon?
In the weeks before
You diet leading up to the event is key, as well as your general health and well being. As such, Dennaoui advises to focus on both micro and macro nutrients and to invest in a multi vitamin to help boost the immune system.
"If you are going to be running in the lead up to the event, you want to focus on your immune system. The last thing you want is to feel ready and then have a cold," Dennaoui told HuffPost Australia.
"Adding garlic to your food is really good, as it increases your blood flow. Vitamin C is important. Hydration is key.
"Although protein, carbs and fats do matter, you have to remember your cells communicate via micro nutrients.
"As such I tell people not to get obsessed with macros in the lead up to the event. Make sure your vitamins and minerals are covered, too."
The night before people go, 'hey I've got this big run tomorrow so I'm going to eat 10 kilos of carbs' and that is not a good plan.Ben Lucas
Assuming you're looking after your vitamins and minerals, Dennaoui says it's time to embrace whole foods.
"Whole food proteins are definitely what I would recommend," he said. "But always have variety with protein. For instance, fish, chicken, meat all have protein. Whey protein has protein. But all offer different micro nutrients which are critical."
Many people think they need to carb load but Dennaoui says it's not necessary in the weeks before.
"You wouldn't overload with carbs a week out," he said. "Normally, you might find you're maybe eating a little bit more, maybe 25 percent more, but you're not loading up."
The night before
On the subject of carb-loading, both Lucas and Dennaoui are of the opinion there is such a thing as having too much, so be careful.
"The night before people go, 'Hey I've got this big run tomorrow so I'm going to eat 10 kilos of carbs' and that is not a good plan," stressed Lucas.
"If your body isn't used to eating foods of that type and in that volume and you jam it all in the night before... they feel like shit the next day. I would be slowly increasing my carb intake the fortnight before, using foods you would normally eat, just in a greater amount. More fruit, more rice, more sweet potato."
"When carb loading the night before, you want low GI carbs like sweet potato, brown rice or quinoa," Dennaoui said. "And you're not sticking to one type of carb, either, the reason being that every carb has different biological value.
"Not only do they have a different set of micro nutrients to offer the body, they also release into the bloodstream at different stages.
"So if you're running a marathon, the type of energy you use at the very beginning is different to the type of energy you use half way through or three-quarters through.
"You want to have a multi stage energy release in the blood. You can have a little bit of protein but don't overdo it. That's more for the recovery process."
The morning of
"The ideal breakfast should be eaten about three hours to 2.5 hours out," Dennaoui said. "You want it to be absorbed and digested so you are ready to utilise the energy.
"I would recommend a nice big bowl of oats with some banana -- so that's for potassium and magnesium to prevent cramping -- and some manuka honey for initial energy.
"If you are going to eat protein, eat them before the carbs."
Lucas has other things on his mind the morning of a big race, and that's making sure you get your bowels working.
"You want your higher GI carbs the morning of the event, so bread and jam or bananas, things like that. Sticky carbs that your body is going to store," he told HuffPost Australia.
"Lots of water and personally I have a coffee early the day of the marathon to make sure the train leaves the tunnel so to speak. You don't want to have that come out during the race. You want to flush that out."
Directly before and during the race
Before the race, Dennaoui recommends eating what he calls "rice cake sandwiches".
"So that's 30 to 45 minutes out from the event," he said. "What they are is a sandwich, but using organic rice cakes as opposed to bread. Put a little bit of nut butter on, so almond butter for example, and banana again and manuka honey.
"These fats help to slow down the release of the carbs in the bloodstream and give you a slow sustained release of energy."
As for those gels you've probably seen people have during the race? Dennaoui isn't moved, but Lucas said they can help given you have trialled them prior to the race and have your preferred brand. He also suggested saving them to drink later in the race (such as the 17km mark) rather than at the beginning.
His other advice?
"During a marathon you must drink. You must -- exclamation mark times one thousand -- drink.
"It's much better to stop at every race station and have some water even if you don't feel like it, because when you do feel like it it's too late.
"The seconds you might cost yourself [at a drink station] might save yourself tens of minutes at the end of the race if you are dehydrated.
"Play the long game and focus on keeping yourself hydrated."
Other racing tips
"Put your ego in your back pocket," Lucas advised. "Before you start a marathon, after all the training that you've done, you're pretty much aware of how fast you are and what time you are going to run.
"Stick to that time. If you are a five minute per kilometre runner, even if you feel amazing on the day and you see people racing past you at four and a half minute k's, do not do that.
"Pace yourself. If you feel good in the last 10 km, open it up there. It's much better to be saving your energy, running at your designated race pace -- which is what you should be at for at least the first half -- and then if you still feel good, to open it up in the last half or even 10 km."