Kick-starting your morning with a healthy breakfast is imperative - it is, after all, the most important meal of the day. Does breakfast in less than 10 minutes sound familiar? It's far too easy to grab something on your way to work. I'm guessing this will usually be a bagel, croissant or other pastry, as that's what I'm often tempted to pick up when I'm running late. But eating a healthy breakfast is essential for maintaining energy and attention levels, as well as for helping you avoid snacking, but there are variations you should focus on, depending on diet, fitness regime and your ultimate goals. We've chosen some of the most common athletic challenges and checked out what healthy breakfast choices are at your disposal when training. The muscle-builder's breakfast OK, so you can go the protein shake route, but really? They're unpleasant and, unless you're a complete muscle nut, no fun. You want to be enjoying your breakfast as well as building those biceps. Picking the right breakfast will not only help with muscle building but will also fill you with energy for the day ahead - a perfect pick-me-up. We're looking to kick-start your metabolism and get your body into an anabolic state by going for high protein, along with some complex carbs and healthy fats. An egg-white omelet with shredded chicken is a winner. Add some finely sliced chili to get the blood flowing and then serve with some avocado diced on top for a healthy fat. With a squeeze of lime (top off with cilantro if you have some), you have mastered the healthy breakfast choice. The marathon breakfast It's highly likely that if you're running a marathon, nerves will get the better of you first thing in the morning and you won't feel like eating. You'll need to try and put aside these fears as best as you can, as getting in the same food you'd consume while training is essential. You're going to need a boatload of foods that release energy slowly to keep you going across those 26.2 miles, but you also need to supply your brain with energy for mental stamina, another key factor in race success. You'll also want to pack in electrolytes (essential for muscle contraction). Oatmeal is ideal: Eat porridge with a banana and a little honey for some added sweetness. You won't be too full, and your body will have an easy time breaking down the foods to leave you ready to lead the charge. More From AskMen: Best Breakfast Cereals 6 Healthy Habits for Living Longer 5 Power Breakfasts 4 Quick & Easy Breakfast Ideas Breakfast Shakes The triathlon breakfast One of the difficulties of eating for a triathlon is that, quite often, you'll be away from home turf, staying in a rental accommodation and out of your culinary comfort zone - exactly the sort of circumstance under which you'd head to a fast-food joint to get a quick fix. Like the marathon runner, you're looking for foods with plenty of slow-release energy that are also convenient. Microwaveable stuff is a plus, but just anything that can be cooked with a minimum of kitchen equipment at your disposal is great. You're also looking for foods that hinder inflammation, as this is often a problem during long periods of exercise. Sweet-potato pancakes are a brilliant healthy breakfast choice for the triathlon runner. Use a pinch of cinnamon, an effective anti-inflammatory, in the batter. Scatter over a mixture of chopped cherries, blueberries, raspberries, and strawberries for some extra vitamins. The fitness challenge breakfast The first thing to do when preparing for a challenge like the Iron Man is to weigh up your opponent - the race itself. During a grueling, lengthy race like this, you'll be burning somewhere in the region of 7,000 calories. You're not only going to need to pack in the calories pre-race but also during - most easily done during the cycle period. You'll need to tailor your breakfast to suit each race, but aiming for a 1,000 to1,500 calorie breakfast is a must, and this is most easily achieved with a combination of foods: bagels with nut butter (try an almond butter for variation), bananas and oatmeal. During the race itself, you're looking to cram in calories quickly during the later stages. Gatorade and coke are ideal. The recovery breakfast The aftermath: You've run your marathon, completed your Iron Man, climbed your mountain, and now are wondering how you get your body back on track. Well, you'll need carbs to refuel your muscles, protein to help repair damaged muscles and potassium-heavy foods to replenish lost electrolytes (far better done with solid foods rather than drinks). A healthy breakfast choice like kedgeree, which is made with rice and smoked fish, is ideal. It's high in protein and carbohydrates, and is easily digestible (and tasty to boot). Dried fruits are often paired with curry flavors and are high in potassium, so add raisins and dried apricots to the mix. Remember that keeping your fluid level up is vital, so keep on drinking.