These days, everyone and their mother is running a marathon. So maybe it’s time you took the endurance racing up a notch. Or five. Yep, we’re talking about completing an actual Ironman triathlon. That’s a 2.4-mile swim, 112-mile bike ride and then a 26.2-mile run.

To help you with this ultimate act of fitness badassery, we tracked down two-time Ironman champ Chris Legh, whom you may have noticed in a certain Gatorade commercial from the mid-aughts. Fresh off a top-55 finish at this year’s Ironman World Championship—at the age of 40—Legh shares a few pro tips below. Good luck!

“There’s a scene in Braveheart where Mel Gibson says, ‘It’s time to go pick a fight.’ And with the Ironman, you’re picking a fight with yourself.”

1. Build up to an Ironman.
The biggest mistake I see now is people just pinpoint an Ironman as their goal from day one, as if it’s just something to tick off a box. You should start with some shorter races. Olympic-length triathlons. Half-Ironmans. Learn a lot about yourself, build up your aerobic strength and physical strength. And then go and do an Ironman. It might take two or three years—it did for me—but I think you’ll enjoy the training process and the race itself a lot more.

2. Train with a partner.
Sometimes I’ll get asked, what do you do on days when you don’t feel like training? The short answer is: train. The slightly longer answer is: find some training partners to motivate you, and get out there. I love training, and for the rest of my life I’ll do that. But I think having friends and great training partners is the key to keeping that training consistency and the enjoyment of training.

3. Learn the difference between fatigue and laziness.
Some days you won’t feel like training. The trick is to figure out if it’s because you’re fatigued—mentally or physically—or if you’re being lazy. If you’re just being lazy, push through it. If you’re truly tired, give yourself some rest. As you progress through your career, you get better at differentiating between the two. For example, when he wasn’t sure if he was feeling tired or lazy, [six-time Ironman world champ] Mark Allen would get on his bike and go ride for a half-hour. And if that fatigue remained, he’d turn around and come home.

4. Aim for quality training over quantity training.
I strive for four really good training days in a week. One day I’ll train for eight hours. But heading into that day, I’ll be rested and ready for it. That wasn’t the case when I was younger. Back then, I would train for maybe five hours the day before. And that doesn’t really work because you’re so tired on the eight-hour training day, you’re really not achieving anything.

Congrats, you finished the swimming and biking. Now all you have left is a MARATHON.

5. Increase your strength—especially in the core.
There’s a lot more to Ironman training than just swimming, biking and running. Like most sports, triathlons are becoming more power-oriented. You need to be strong, particularly through the second half of the marathon. One of the ways to improve your strength is to build up your core. [Six-time Ironman world champ] Dave Scott, for example, places a huge priority on core. You could spend an hour a day on core exercises—planks, Swiss ball work, etc.—and you’d see a huge return.

6. Don’t overdo the pre-race carbo load.
At a lot of triathlons, there’s a carbo dinner the day before the race. And you’ll see people walking back to the buffet line three or four times with pasta. That’s definitely overdoing it. For me, it’s a case of probably six meals in a row where I cut back a little on protein and my carbohydrates go up. So the portions stay the same but the composition changes. Once your muscles and your liver are full of glycogen, the job’s been accomplished. It’s like a gas tank in a car—once it’s full, it’s full.

7. Stay fueled during the race.
You lose a lot of sweat and sodium during an Ironman, so you have to stay hydrated. I should know—I almost died in 1997 from complications due to dehydration. When the race starts, we have our bottles on a fuel belt or in a fuel box. I start off with Gatorade Endurance Formula, a liquid. Then later, I’ll take some Gatorade carb energy chews. There will also be gels and other drinks on the course. But then halfway through the bike portion we pick up a bag that’s stocked with whatever we want.

8. Keep talking to yourself.
I remember [eight-time Ironman world champ] Paula Newby-Fraser saying that the Ironman is “just one long, tedious conversation with yourself.” And that’s a perfect way to put it. I’ve got another saying. There’s a scene in Braveheart where Mel Gibson says, “It’s time to go pick a fight.” And with the Ironman, it’s time to go pick a fight with yourself. Over the years, I’ve learned to really enjoy that battle with myself. You go through these highs and lows, but the reward at the end is fantastic.