Lack of Time

A lack of time is perhaps one of the most common excuses many people use to avoid exercise. Misinformation about what actually constitutes physical activity can make beginning a formal exercise routine daunting, to say the least. Even finding time for the recommended 30 minutes of daily aerobic activity can be tricky for many busy people. But according to the American Heart Association, adding small doses of extra activity to your daily routine can add up to a big chunk of time. If you divide physical activity into three 10 minute segments each day, you'll reap the same benefits as if you exercised for 30 minutes straight. Even performing simple tasks like taking the stairs or parking your car farther from the store or the office count.

Lack of Motivation

Many people simply have a lack of motivation to exercise, according to licensed mental health counselor and behavioral specialist Jenny Shaw in an article for BenefitUAmerica. People sometimes just cannot find a "good enough" reason to get out and start exercising, even if deep down, they know they should. Often, people begin an exercise regimen to slim down for a special event or vacation, but once the event passes, their motivation to continue exercising also subsides. Long-lasting motivation to exercise usually comes from creating goals that involve improved health or fitness, not just better physical appearance.

Lack of Self-Confidence

Although a lack of time or motivation might be common reasons many people decide to avoid exercise, Deborah Dunham suggests in an article for Blisstree.com that the real reason behind these excuses might be a lack of self-confidence. A lack of self-confidence can lead to reduced feelings of self-efficacy, which essentially means that you won't exercise if you feel like you can't do it or that you will ultimately fail if you even give it a shot. The irony is that you only reinforce your feelings of failure by continuing to rely on this excuse. Even taking the first steps toward beginning an exercise program, such as walking around the block after dinner, can help increase your self-confidence and prove that you can succeed.

Lack of Money

People often assume that it costs a lot of money to exercise. You might think the expenses of joining a trendy fitness club or purchasing pricey exercise equipment are reasons enough to avoid exercise, especially if you're on a tight budget. But you don't need to spend your hard-earned money to perform many types of exercise -- running or walking only requires a decent pair of sneakers. And according to fitness and wellness expert Jessica Smith in an interview with "Shape" magazine, walking or running outdoors is one of the best ways to burn calories and improve coordination and balance.