A regular workout routine is important for your body, but if you stick with the same workout day after day, you may stop seeing results. There are a lot of factors that affect how much your workout will alter your physique. Two of the most important: Consistency and timing.

When you first start a routine, you tend to score quick fitness gains. Yet after a couple of months, you may feel like you’ve plateaued and aren’t seeing further progress. Most fitness experts suggest changing your workout routine every six to eight weeks to avoid this plateau. Ultimately, your muscles adapt to a consistent workout and need confusion in order to continue to grow. Here are some signs that you should switch up your workout.

1. Your workout has become easy

When you start a new routine, you’ll most likely feel the burn from start to finish. The longer you do the routine, the easier this becomes until it’s eventually too easy. At this point, the best move is to increase the weight and/or reps.

2. You’re bored

Doing the same routine in the same order day after day will inevitably get boring. In order to stay engaged, add variety: cardio, weightlifting, interval training, and bodyweight exercises.

3. Your heart rate isn’t challenged

If your heart rate is staying relatively low during what used to be a tough exercise, it’s time to change your routine. Aim to keep your heart rate at 60-80% of your max for most of any high intensity or cardio workout for the best results.

4. You aren’t sore afterwards

We’ve all heard the saying, “no pain, no gain.” And while you should never overwork your muscles to the point of exhaustion or injury, every time you lift weights you should feel slightly sore afterwards. Once the ache is gone, it’s a good signal to increase the weight.

5. You’re completely exhausted afterwards

Extreme fatigue is a sign that you need to eat more, get more rest, or dial back on the intensity of your program. Again, a good workout is just that—work—but it shouldn’t completely drain your energy.