When I was young I never seemed to be aware of how tired my brain could feel. Maybe it was just youth, or maybe I wasn't really stretching it to the limit. These days, between writing columns and books and consulting, I often feel some aspect of brain fatigue. I get to those moments where I have been making so many decisions, or trying so hard to be creative, or doing so much analysis, that I just start to wander and mentally move slowly.

For the most part, my clients and readers are not concerned with how efficient or productive I am; they desire only the output. So the responsibility of overcoming fatigue and boosting my brain falls 100 percent on my shoulders.

My number one remedy for brain fatigue is people watching. Luckily, I live in Manhattan, where there are plenty of interesting people to watch. I find that the visual stimulation of real-life activity makes my brain wake up and think in new ways. Just imagining the stories behind these active, busy people is enough to trigger my imagination and sharpen my powers of observation. So next time you feel like you just can't think, go get a dose of humanity. Try any public transportation, around the 5 p.m. commute.

Here are more brain boosters from my Inc. colleagues.

1. Try alternative activity.

The easiest way for me to get a boost is to stop working and start working out. (But don't go too hard; then all you can think about is your next breath.) Moderate-intensity exercise strips away the mental clutter and opens you up to some cool mental places. If that's not possible, whenever your work makes you sluggish, simply go do something else. Go do anything else. When you're stale, that means you're not excited--so put the present aside and turn to something that will excite you. That energy will automatically bleed over into other areas of your business or personal life. --Jeff Haden, Owner's Manual

Want to read more from Jeff? Click here.

2. Take some steps.

One of my favorite things to do when I'm feeling fried or played out is to go for a walk. Walking soothes the brain--so much so that Buddhists use it in their meditation practice. Many of my best ideas, headlines, and the first few lines of many articles and book chapters have come to me while taking a walk. It doesn't have to be a long or vigorous hike--10 to 15 minutes is enough. My brain works best when I walk someplace very familiar. Not having to think about where I am seems to free my mind and get it working again. --Minda Zetlin, Start Me Up

Want to read more from Minda? Click here.

3. Grab a liquid jolt.

One word: espresso. OK--two words: grande mocha. Truth be told, there's nothing like a quick jolt of caffeine to give my brain a quick boost. I'm careful not to overdo it though--too much of a good thing can be too much. That said, my espresso machine is never far away from my desk. --Peter Economy, The Management Guy

Want to read more from Peter? Click here.

4. Enjoy a distraction.

The brain is like any other part of the body; it tells us when it's had enough, yet we often ignore the signals. I've learned that rather than attempting to force creativity or concentration, I stop whatever I'm doing and engage in a "no-brainer" activity. From playing with the dogs to running errands, activities that are of a physical nature are great distractions and refuel the mind. Just yesterday, I treated myself to a massage--that really helped! Everything seems to fall into place when I go back to the drawing board feeling mentally refreshed. Take the path of least resistance, and your brain will reward you! --Marla TabakaThe Successful Soloist

Want to read more from Marla? Click here.

5. Do Something Alone

The solitude of swimming laps at my local gym is the best way to think through a problem and get the blood flowing through my brain. There is no Internet, no email, no phone, no social media--just the solitude of the pool and the ability to focus on a task or problem I am trying to work through. Other people use cycling, running, or a walk through the woods in the same way. While you may argue that exercise is not a quick boost, I find that I lose more time not taking the break and willing myself to "be creative" or "find inspiration." It's in those active times away from my desk that the cobwebs clear and my thoughts are refreshed. --Eric HoltzclawLean Forward

Want to read more from Eric? Click here.

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