In reality, the more you are prone to lying, the more you have to fabricate details and events to create a cover story. Lies breed more lies. Research indicates the accompanying stress can be harmful and even exhausting. The longer a person attempts to “keep a story straight,” the more stress and strain is felt.
That discomfort can possibly lead to more serious side effects in the future. A Columbia University study shows stressed-out people were 27 percent more likely to have heart attacks compared to those who worried less. Stanford researchers conducted a study to measure the effect of lying on a group of participants. Acknowledging dishonest acts made physical tasks such as working out or helping someone move feel more taxing. In addition, deceptive participants suggested that hills seemed steeper and distances seemed farther.
Deceptive thoughts may activate parts of your brain tied to perception and vision in the same way as when you are physically weighed down. This can lead to physical overexertion, exhaustion and stress. Therefore, the heavier the lie you’re dealing with, the heavier those bench presses may feel. Notre Dame researchers found that subjects that were told to explicitly tell the truth reported lying less frequently and reported having improved relationships, better sleep, and less tension, as well as fewer headaches and sore throats.
Source: http://www.today.com/health/how-one-lie-can-ruin-your-whole-day-1D80224805#