There’s no one way to run a marathon. You need to find out what works for you and exploit it. While you’re figuring out your strengths, avoid these common marathon mistakes that will keep you from reaching your marathon goals.

Wrong Goal: This is crucial. Just because the friend you are running the marathon with wants to try and finish in under four hours does not mean you have to. Your goal should be based off of your pace and your running ability. If this is your first marathon, focus on the finish and make a goal for your next race based on your results.

Wrong Training Plan: Some training plans are for six days a week, some for three days a week. Find one that works best for you. Running every day is not for everybody and if you pick a plan with much more running than you are already used to, you will set yourself up for failure. Check out www.runnersworld.com to make your own personalized training plan.

Lack of Belief: If you go into this training and race thinking “I probably won’t finish, but here is to trying,” you probably won’t finish. Endurance running is 90 percent mental. Do you think your body enjoys running 26.2 miles? Of course not. That is why you need to strengthen your mind to push your body through. Believe in yourself and visualize crossing that finish line.

Lack of Support: Running a marathon is a huge accomplishment and you cannot do it without the support of family and friends. Whether you have a buddy you are training with or friends and family that you update your training with, support is key. Also, make sure you have people at different mile markers on race day. When you are 15 miles deep and you see a friend or family member on the sideline, it will give you a burst of energy and inspiration.

Underestimate Stretching: Stretching is just as important as the running element of your training program. Your muscles and hip flexors especially will start to get pretty tight, so keep up with consistent stretching to help your legs stay fresh and avoid injury.

Starting Too Fast: This is common for beginner and veteran marathoners alike. Sometimes the excitement at the start of the race gets your adrenaline pumping so hard that you throw all your pacing goals to the wind. It may seem like everyone around you is booking it at the start. Be patient. It is always better to have enough energy to kick it into gear at the end, rather than crawling to the finish line because you started too fast.

Not Practicing Nutrition: Never wait until race day to try a new gel pack or a power bar. Experiment with nutrition during your training runs. There are certain products that may upset your stomach and it is better to find out during a training run rather than on race day.

Not Eating/Hydrating enough: Not fueling correctly before a long run or a race can cause your body to break down fast. Sometimes after long runs you will experience a “running hangover”—this is normal. However, a running hangover after a run in addition to not being properly fueled will be worse. Your body will feel like it is going into shock if you do not hydrate and eat properly. Do not let it get to this point.

Follow these general guidelines and you’ll be well on your way to finishing a successful marathon.