Whether you’re dealing with a serious health problem, or you’re faced with a financial crisis, tough times are inevitable. And it’s during those tough times that your mental strength will be tested.

Without adequate mental strength, life’s inevitable challenges will likely fill you with self-doubt and anxiety. Those uncomfortable feelings can lend way to negative thinking. And negative thinking will affect your behavior–which can inadvertently turn your catastrophic predictions into a self-fulfilling prophecy.

Accept reality.

Acceptance doesn’t mean agreement. Instead, it’s about acknowledging what is happening from a realistic standpoint. So while you may not agree with things like racism, you can accept that it happens.

Digging in your heels and saying, “I shouldn’t have to deal with this,” only wastes your valuable time and energy. Accepting what is happening right now–regardless of whether you think it’s right–is the first step in deciding how to respond.

For example, one person stuck in a traffic jam says, “This isn’t fair! Why do these things always have to happen to me?” His thoughts cause him to feel angry, frustrated, and anxious. He starts banging his fists on the dashboard and screaming at other drivers.

Another driver who is stuck in the same traffic jam reminds himself, “There are millions of cars on the road every day. Traffic jams are bound to happen sometimes.” His point of view helps him stay calm and he listens to a podcast while he waits for cars to start moving again.

Accepting reality is about recognizing what’s within your control. When you can’t control the situation, focus on controlling yourself.

Behave productively.

Accepting reality helps you manage your thoughts and regulate your emotions–which are key to productive behavior. The choices you make when you’re faced with problems determine how quickly you’ll find a solution.

Unproductive behavior, like complaining or throwing a pity party, will keep you stuck. Those behaviors will rob of mental strength.

So it’s important to ask yourself, “What’s one thing I can do right now to help myself?” Whether productive behavior involves facing a fear, or doing something you really don’t want to do, take action.

Control upsetting thoughts.

Your mind can be your best asset or your biggest enemy. If you believe your negative thoughts, your self-limiting beliefs will prevent you from reaching your greatest potential.

Thinking, “This will never work. I’m not good enough,” or, “I can’t stand one more minute of this,” will derail you from your goals. It’s important to recognize when your inner monologue becomes overly pessimistic. Remember that just because you think something, doesn’t make it true.

Talk to yourself like you’d talk to a trusted friend. When your thoughts become catastrophic or unhelpful, respond with a more realistic statement that confirms your ability to handle your struggles.

Build Mental Strength Before Strong Is the Only Choice You Have

Building mental strength is similar to building physical strength. While you may not think about your mental muscle until you need it the most, a crisis isn’t the best time to build mental strength.

Similarly, you don’t want to wait until you have to lift a heavy object to start building physical strength, right? Pumping iron for five minutes before you move a couch isn’t going to do you much good. But steadily building strength over time can ensure you have the muscle you need when you have more weight to carry.

Think of mental strength in the same way. There will be times when you’re going to need all the mental strength you can muster. So it’s important to make mental strength training a daily habit.

And then, when you find yourself going through tough times, practice the ABC formula. Those three steps will ensure your struggles make you even stronger.