Goals are important. Without them, we’d lack the drive and focus to get anything done. Some researchers have even argued that the complexity of human goal-oriented behavior is what differentiates us from other species.

Interestingly, failing to achieve goals is also very human, and, as it turns out, very necessary. When it comes to mastering a new skill, our development is maximized when we try something that is somewhat difficult that results in failure about half of the time. (Who knew?)

However, creating goals that are too far out of reach—or when it comes to health and fitness, are not constructive—can lead to defeat, and ultimately giving up. Learning how to create suitable goals is worth the effort, as it can help you better focus on what you want to achieve and get you there with smaller losses and bigger wins.

Goals That Stick

In terms of health and fitness, goal setting is strongly related to behavior change, well-being, and performance. It’s most effective when they are:

  • SMART (specific, measurable, attainable, realistic, and time-bound)
  • Challenging (but not too challenging)
  • Targeted for the near future (months, rather than years)
  • Focused on self-mastery instead of outperforming others (wanting to become better than before instead of competing against peers)
  • Accompanied with progress-related feedback (self-monitoring through tracking physical activity or diet)

Goals That Aren’t Attainable

One of the fastest ways to set yourself up for a big fail is to aim for an unattainable goal. A classic example is to set a goal to lose a lot of pounds in a very short time frame. The weight-loss recommendation for a typical person—that is, a person who is not on a medically supervised weight loss regimen—is to drop about 1 to 2 pounds per week. Losing weight at a more rapid rate (e.g., 30 pounds in 30 days) results in excess losses of body water and muscle tissue, neither of which is a good idea for optimal health.

Other examples include goals that require you to completely overhaul your life in a short period of time. While it might be physiologically possible for you to take up a new, intense workout program and adopt a specialized diet for a few months, your work and family life might not allow you the flexibility to sustain something that rigid long-term.

For greater success at setting goals you’ll actually achieve, ditch the following ones and opt for more reasonable approaches instead.

1. Don’t focus on a specific number of pounds you want to lose.

The bathroom scale can be deceiving and demotivating, as it doesn’t differentiate between fat and lean weight, or between being bloated and dehydrated. Setting goals based solely on losing body weight may set you up for feelings of failure, especially when you weigh yourself frequently and see the pounds fluctuating.Having a targeted weight to shoot for is fine, but in addition to weight loss, track your body composition (i.e., the percentages of fat and lean mass that make up your total body weight). If you’re exercising regularly and eating a nutritious diet, you’ll likely be gaining muscle and simultaneously losing body fat, so the bathroom scale might not give you the whole picture.Do this instead:Set behavior-based goals around improving your health.Find a goal that will enhance not just how you look, but how you feel, like improving strength, flexibility, or stamina. Examples include adding a yoga routine to your weekly workouts, training for a 5K, or even just adding an extra few minutes to a daily walk to go a bit further.If you like the way these new habits make you feel, you’re more likely to stick with them, which ultimately results in achieving a better body composition. The scale may or may not show weight loss, but the you’ll look and feel better.

2. Don’t go to extremes when you’re not ready.

Competing in extreme fitness challenges such as obstacle course races, marathons, and triathlons are lauded as striking accomplishments, as well they should be. These endeavors push competitors to the limits of their physical and psychological capacities. As such, extreme fitness events like these are best reserved for athletes who have logged months, if not years, of performance training.If you’re just getting started, focus your goals on lesser challenges, at least in the beginning. Certainly, setting a goal to one day compete in an extreme event isn’t problematic. But it becomes risky when a person signs up for an event without a clear understanding of the training effort required and competes prematurely.For example, in the case of running, some evidence suggests that training errors, including excessive distance and sudden changes in training routines, are the cause of 60-70 percent of all running injuries.Do this instead: Try more sustainable challenges that lead to continued exercise habits.Frame your training around slowly building fitness at a steady pace instead of throwing yourself into a challenge you’re not physically ready for. If your goal is to run a marathon, give yourself plenty of time (at least a year) to prepare. In the short term, set your sights on competing in a shorter challenge, like a 5K, to give yourself a timelier deadline. This approach will allow you to self-select your exertion during exercise; reduce the risk of musculoskeletal injuries associated with doing too much, too soon; and help you stick with it.Keeping yourself injury free is one of the best ways to ensure that your exercise routine remains enjoyable. You’ll also be building strength and endurance to eventually challenge yourself to do bigger races.

3. Don’t aspire to look like fitness models.

Comparing yourself to unrealistic (and potentially fake) imagesof models is enough to make anyone feel less than. Feeling bad about yourself is not an effective long-term motivation strategy. The fact is, not all bodies are shaped the same way, nor will they respond similarly to the same diets or exercise programs. Placing pressure on yourself to conform to an unrealistic body image might motivate you to hit it hard in the gym for a while, but it’s likely to make you eventually drop out and wind up with feelings of shame and guilt.Do this instead: Find physical activities that spark joy.Research demonstrates that people who report enjoyment during exercise are more likely to adhere to being active in the future. Seek out physical activities that you enjoy and that will keep you coming back for more. If you like to dance, set a goal to enroll in a dance class and attend regularly, or join a local sporting league with supportive friends.When you’re happy and regularly active, it’s bound to improve your physical condition, which over time can lead to the outward signs of fitness. You’ll be developing the healthiest, happiest version of you, and who wouldn’t find that sexy?

What If You Fail?

Even reasonable goals that seem attainable can sometimes lead to failure, and that’s OK, as long as you don’t use it as an excuse to give up. Sometimes failing is necessary to learn what doesn’t work. In fact, success rates for adults who make multiple attempts at self-change are higher than for those who undergo a single attempt. Don’t be too hard on yourself. If you don’t reach your goal, refine it and try again.

Sabrena Jo is the senior exercise scientist for the American Council on Exercise, where she gets to follow her passion of relentlessly pursuing ways to help people start and stick with physical activity. Follow her on Instagram and Twitter.