Most endurance runners are well acquainted with the idea of a gradual ramp-up of speed and distance over several months. But how about all the other stuff that is not necessarily in a training guide?
1. How to avoid raw thighs
Chafing and blisters happen because of friction. Take two objects rubbing together (your thighs, or your toe and sock), add heat and you will get friction.
And sweat just makes it worse.
To avoid it, choose smooth, seamless fabrics that wick away moisture and use anti-chafing products.
Mr Carl Ford, a running coach and a finisher of 24 marathons and two ultramarathons, said smear anything that "sticks out".
Nipples? Yes. Inner thighs? Yes. And, also, unexpected areas such as the stomach.
There are nipple protectors on the market, but small circular bandages might do the trick.
Mr Lee Firestone, a Washington podiatrist and running coach, recommends tight acrylic socks and reliable running shoes, and keeping toenails short.
Lace your shoes higher to prevent your foot from moving around in your shoe, which can cause too much skin friction. "We often get blisters running downhill because the foot is moving forward in the shoe," he said.
2. Energy without gastric distress
"Part of your training is to figure out when and what to eat and drink, depending on the distance you're running," Mr Ford said.
See what works in your body, said triathlon coach Debi Bernardes. Some athletes eat two to four hours before a training run or race, while others just have water. For longer runs and races, many runners need some food mid-run. Sports gels are popular, although some prefer "real" food.
Surprises can include cramps and diarrhoea. The likely reasons for so many runners having gastric distress include jostling of the organs, nerves and anxiety, and a lack of blood flow to the intestines.
Coaches recommend hydrating appropriately, avoiding caffeine and alcohol, and reducing anxiety as much as possible.
3. Slow down on hot days
Whether you are training or racing, a hot day is likely to mean a slower pace. Or, as Mr Ford experienced in a marathon a few years ago, you might get lead legs with a significant distance to go.
"The last part was a death march," he said. He was taking part in a marathon in New Orleans in late February and it was humid.
"I didn't fully account for the humidity and my pace was too fast in the beginning," he said.
And make sure you are dressed properly for the weather. Many runners wear clothes for weather above the actual temperature.
Many use throwaway layers they can discard during the race.
4. Hydration: Early and often
If you train early in the day, Ms Bernardes recommends water with a pinch of sea salt when you wake up, to replenish the salts you lose breathing throughout the night.
"Too many athletes just drink water, not realising that they are actually flushing their store of electrolytes," she said.
The main thing about hydration is to never wait until you are thirsty.
The amount of hydration needed is dependent on several things, including your sweat rate.
To find out how much you need to hydrate, Mr Firestone recommends checking the colour of your urine after training runs and weighing yourself to see how much weight in fluids you need to replenish.
Also, if you are racing, make sure your stomach can tolerate the particular sports drink featured in the race. You can usually find out the brand on the race website. Buy a can and try it on a training run.