After countless hours of training and sacrificing time with family and friends, the last thing you want is for all your efforts to come to naught on race day.
Evan Chee paid special attention to the difficulty and challenges for the inaugural Bangkok Midnight Marathon in May, and was well prepared for it.
He said: " I felt pretty good, having clocked peak weekly mileage of about 120km.
"I knew it was going to be a hot and humid night race, just like in Singapore. And since we were racing on an elevated highway, I wanted to start conservatively to keep my heart rate in check."
His reward was emerging as the top Asian and fourth overall.
Like Chee, who is managed by ONEathlete, you can also enjoy an optimal race -day experience.
BEFORE THE RACE
For starters, get a good rest two nights before race day as it is near impossible to get enough sleep the night before. Insufficient rest results in fatigue and a greater risk of getting yourself injured.
You would have probably done carbohydrate loading in the preceding days. As one's energy stores will still deplete to some extent while you sleep, it is important to consume carbohydrate-rich and fast-digesting food about two hours before flag-off.
Eat only foods that you are familiar with and do not make drastic changes to your race-day breakfast. Drink about 300 to 400ml of water at least 11/2 hours before flag-off to optimise hydration and allow adequate time for toilet breaks.
Avoid alcohol as it causes dehydration and predisposes one to low blood sugar levels.
Get to the race venue early so you have time to deposit your baggage and go for toilet breaks, if needed.
Remember to write your medical history and drug allergies (if any) on the back of your race bib so that the appropriate treatment can be administered in the event of a medical emergency. Do not forget to include the phone number of your loved one(s) as well so that they can be contacted if the need arises.
What if you feel unwell on race day?
If you have symptoms in the areas below the neck, such as fever, generalised fatigue, chest congestion, upset stomach or body aches, I would advise you not to run.
Symptoms that show up above the neck - runny nose, nasal congestion, sneezing, minor sore throat - are more forgiving and you may proceed with the race. However, consider reducing your running speed or stopping, should you feel more unwell during the race.
Running with a fever can cause your temperature to rise even higher and put your heart under greater strain.
Doctors make the worst patients. I once ignored medical advice and attempted to run while stricken with influenza: 38 deg C fever, body aches and chills. I lasted about 2km and had to stop as I was feeling more feverish than ever and also developed heart palpitations.
For morning races, note that it gets especially hot from 9am onwards. If you anticipate you will be running at that time, consider applying sunscreen to reduce the risk of sunburn.
To avoid painful skin abrasions, apply petroleum jelly to areas such as the nipples, underarms and inner thighs. If you dislike the idea of using petroleum jelly because it stains the running apparel, Band-Aid plasters can be a good alternative in preventing nipple abrasions.
DURING THE RACE
At drink stations, do not jostle or rush. Consider collecting drinks at the further end of the station, where it is usually less crowded. Drink just enough to quench your thirst. Drinking beyond the point of thirst can result in low blood salt levels (hyponatremia) which can cause giddiness, confusion and even loss of consciousness.
For short races less than an hour, water is the fluid of choice. For longer events, glucose-electrolyte drinks are ideal. If you consume energy gels, ensure that you down them with a few mouthfuls of water to help in absorption.
If you run with earphones, ensure the volume is at a low level so you can still hear your surroundings. Situational awareness is important.
Look behind you before coming to a sudden stop. Move to the left if you decide to slow down to allow faster runners to pass. Just as drivers check their blind spots before changing lanes and overtaking, take a quick glance diagonally behind you before overtaking others to avoid hitting fellow runners.
Stay safe and enjoy your race.
•Dr Wang Mingchang is a family physician with the National University Hospital Sports Centre. He has completed 10 marathons.