Even for normal runners, marathon training is a steep learning curve. If you run a few times a week and tear it down every Saturday in your parkrun, you do not have to worry too much about what equipment to wear. If you need to cover the long distances for a 42.2-kilometer race, you need to consider how to avoid injury to adapt and vary all that you need to do, and last but not least, how to use your body for all refuel this exercise.
Most, if not all, fuel should be fueled by your body's diet, but there are times when it is not possible or desirable to consume real food – one of which is the race itself – and here can help supplements.
The key supplements to consider are those that replenish your carbohydrate reserves and electrolytes during long runs and those that help you to replenish and recover during a strenuous exercise regimen. There are also supplements like beetroot juice and caffeine that can boost your performance. In short, there are many different supplements that you can use to help your body meet the demands of marathon training. Here are the top types you will come across.
Probably the most common supplement to marathon training. These are mocked by runners during long runs (over 90 minutes each) to replenish their carbohydrate reserves. In the marathon itself, you'll probably go through four out of five gels ̵
Buy at SiS | £ 28 for 20 Mixed Flavors
This is a combination of carbohydrates and electrolytes that can be refueled well before or during longer runs. You do not want them with you for the event itself, which is why most people opt for portable gels and electrolyte tabs, but they are good during exercise or if you can take them along during the race.  Try: Lucozade Sport
Buy at Amazon £ 15 for 12
Pop them in water and dissolve quickly to form an electrolyte-rich cocktail that contains minerals like sodium, potassium, and magnesium that help the body self to hydrate. Carb gels generally do not have electrolytes that you need to replenish during prolonged exercise and sweat a lot. If you have the tab with you, you can just bring water during the race and make your own electrolyte drink.
Try: High5 Zero
Buy at Amazon £ 5.99 for two 20-tab tubes
Studies on nitrates in foods such as beetroot, spinach, and rocket suggest that they can positively impact performance in endurance activities – Apparently, Leicester City used beet juice in their Premier League title season with great effect. Beet It Shots contain 400 mg of nitrate from food. Try to drink them daily in the week before your event and have a couple in the 12 hours before.
Try: Beet It
Buy At Amazon | £ 21.26 for 15
When weightlifters finish a workout, they grab a protein shake. But even though runners need protein, it's more important to replenish carbohydrates and electrolytes. If you are on a busy exercise program and have no time or inclination to do so through meals, then a recreational drink such as SiS REGO, which contains carbohydrates, egg whites and electrolytes, is useful. 
Try: SiS REGO Rapid Recovery +
Buy from SiS | £ 43 for 1,54kg
We do not mean to drink coffee before running, especially because this is a gastrointestinal risk that only the daredevil would go for, but versions The above supplements containing caffeine can give a timely boost. Store a running gel or electrolyte drink with added caffeine for kilometer 30 of your marathon – it could be just what your body and brain need to get you to the finish.  Try: OTE Caffeine Gel
Buy at OTE | £ 35.10 for 20
Wear a bag of it while running, and you can use it to mix a sports drink wherever you find water by removing the carbohydrates of a running gel and the electrolytes deploy from a tab in one go. The bags are a bit bulkier than gels or tabs, and pouring the powder into a bottle requires some skill, but if you master the trick, you'll have everything you need to reach the finish line.
Try: Maurten 320 Drink Mix
Buy at Maurten | 44,80 € (around 40 €) for 14 bags
They are heavier on the road than a sports drink or gel, but energy bars generally have the advantage that they are probably all tastier and less palatable Rupture gastrointestinal feathers. If you're running an ultramarathon or attending events that stop you refueling, energy bars are a good choice. They are also suitable for a great snack before the race.  Try: Clif Bars
Buy on Amazon £ 17,048 for 12 bars