It's super hard to perform at peak levels when you feel tired and sick. Everyone succumbs to the occasional cold or stomach bug, but have you noticed the most successful people seem to be nearly invincible?

It's no coincidence. Successful people value themselves highly and invest in their own well-being. They enjoy life, and don't want illness or injury to disrupt their trajectory. With winter and the holidays ahead, there is no better time to be thinking about staying healthy. To keep you at your best, here are seven simple habits that will help you stay healthy and enjoy your rise to the top.

1. They schedule their eating.

Sporadic munching leads to unhealthy snacking and inconsistent energy. Food is a foundation of life. Successful people make sure they regulate the foods they eat so they avoid massive highs and lows. All caffeine and sugar all the time will lead to a crash-and-burn scenario that will limit long-term performance. The more rhythm you put on your eating, the less you will focus on hunger or thirst. You can then refocus that energy on more important things.

2. They integrate their diet.

Busy business people can't easily control the food available to them everywhere they go. There are always events, travel, and gatherings that will dictate the foods available. Partake of just what's there and you'll end up increasing your clothing size regularly. Successful people know which foods are healthy and can improvise in any scenario. They create habits of healthy eating that keep them feeling at the top of their game. They master moderation of food and drink so they can stay healthy and sharp. Mentally monitor your intake appropriately for your activity. You never want to miss an opportunity from rushing to the bathroom or being sloshed from the fifth tequila round.

3. They amortize their exercise.

As people get older, exercise is less of a quick fix for poor diet habits (trust me, I learned this the hard way). Exercise, however, is critical for conditioning of the body and long-term health. Successful people commit enough time to being active without overcommitting to a binge and purge exercise regimen. Regular walking and being active can help you maintain health if you manage your diet appropriately. Commit to what your time will allow so you don't abandon your activity when you get busy.

4. They treat their mind like a muscle.

The mind needs to be exercised, fed, and relaxed just like any muscle in your body. Successful people know that great thinking doesn't come without practice and conditioning. Schedule your creative thinking for when you are up to the task and make sure you take a break when feeling fatigued and overtaxed.

5. They maintain a positive attitude.

When negative energy is flowing, it can eat at your soul and your body as well. Successful people find ways to relieve the emotional stress and find the positive in the challenges of the day. They reward themselves for little wins so their endorphins are flowing regularly. Most of all, they laugh. There is very little that is so serious in business that a good-natured chuckle now and then isn't readily available to pick up the spirit.

6. They rely on professionals.

Young people often feel invincible and treat their health care accordingly. Unfortunately for many, serious issues can show themselves at any age unexpectedly. An annual checkup goes a long way toward prevention. Successful people know it's far better to find out some concerning news early than it is to hear dramatic news that didn't have to be.

7. They give themselves a rest.

The body requires rest to perform at its best. Not only does shortchanging sleep take its toll on health, but relaxation is also required for maximum performance. Successful people schedule time to rest. They use advanced techniques such as meditation to calm the mind and truly rejuvenate. Best to let the body take on it's natural regeneration process so you can take it to its limit when you really need to.