Too Much of the Same Old Cardio Routine 

The body responds best to exercise when it doesn't know what to expect. Sticking with the same form of cardio each time that you work out may seem comfortable and familiar, but it isn't going to give you the resistance that you need. If possible, it should be switched up each time. Perhaps, one day a week is used for speed walking around the track, and three other days are spent kickboxing or dancing. Then, switch this routine up the next week, so that the walking is replaced with jogging or biking. 

Avoiding Strength Training 

Sometimes, people involved in an active adult life stick with cardio exercises because they think that weightlifting is only for bodybuilders. This simply isn't true! It helps increase lean muscle mass, which is important for fat burning. Bone density is also improved with weight-bearing exercises. A good way to start out is with a small pair of hand weights that are just one or two pounds each. Then, increase the amount of weight over time. Gravity can also be used as a form of resistance to work against though. Planks and push-ups are two strength training exercises that can give a person the same effect without weights.  

Training Too Much 

Working out seven days a week for hours at a time isn't necessary. It can actually be counterproductive and increase the risk of an injury of the joints and muscles. The body needs time to heal in between workouts because too much inflammation will develop. This is especially dangerous for those who have previously sustained injuries. Shorter, more intense workouts are more effective because they increase fat burning and muscle mass faster.  

Setting Unrealistic Goals