The entrepreneurial workday is grueling, and it usually doesn't end at a mere eight hours. Because you want to stay efficient and produce high-quality work, you'll need to be on your game mentally and cognitively. Certain days your work hours fly by and you feel productive and highly energetic the whole time. Other days you feel cumbersome, slow, and unmotivated.

Producing more of those positive days is made even more challenging when you're bogged-down by other factors. In particular, you may have draining events in your life happening outside of the office. Family and personal drama, as well as other inconveniences that come with living, make it harder to sustain stamina and attention at work.

When you feel slow, distant, or lack vitality, try these five-minute energy boosting activities. These will help sustain your hard work -- all day long.

Jumping jacks, push ups, or other quick physical exercise

When you're sitting all day long, getting up to move can serve as a refreshing and motivating break from the tasks at hand. You can perform these exercises at your desk, in the break room, or even outside if it's a nice day.

A study this year by the Journal of Cognitive Enhancement showed that physical exercise can boost cognition both during and following exercise. Therefore, know that quick exercise can get you out of your routine and get that brain firing on all cylinders.

Even if it's just for a few minutes, getting your heart rate up and burning calories is positive for your physical health.

Think back on pleasant memories

In 2016, European researchers organized a study in which they asked people to stop and pay attention to how memories made them feel. Their results, published in the Journal of Behaviour Research and Therapy, showed that participants experienced more positive emotions when thinking back on a past positive memory.

You can take advantage of this. Recalling a time that made you happy takes mere seconds. Even more, it's a break from whatever tedious, detail-oriented task you're doing. Take a moment and recall a pleasant past event. Within minutes you'll create positive emotions that can boost your effort to get work done.

This may sound too easy to actually work. But in my experience it does. I keep an ongoing file of past work achievements on hand for this. 

Sit up straight

This one may seem trivial too at first. But, body language can have a serious impact on the way you feel.

A 2015 study in the Journal of Emotion and Cognition found that sitting up straight helped subjects recover from a negative mood. People felt happier when they were in a neutral mood, then how they felt when they were slouching.

When you feel low energy, take a break and focus on your posture. Sit up straight instead of being hunched over, and you may just start to feel better.

Remember that time is scarce

It may seem counterintuitive, but people who know they only have limited time to accomplish something often feel better than those who don't know. In 2016, Cambridge researchers asked study participants to live as if they were going to be leaving their current city soon and that time was scarce. When imaging in this way participants reported higher levels of positive emotions. They said they felt more satisfaction in life and had lower levels of negativity.

All of this makes sense. Researchers said participants felt greater connectedness, competence and autonomy. Recalling that time is limited may force you to seize moments and make the most of situations.

When considering your personal work, it may take some thought to reflect on how this applies to you. But, imagine if you only had a limited time to complete whatever work might be important to you right now. This could help galvanize you into action and greater productivity.

Watch an inspirational music video

One trick that always works is watching an inspirational music video when I am feeling low energy. Queen's Live Aid performance does the trick for me. The combination of the music itself, and the incredible effort and talent here, injects energy into the most comatose work day. When I return to work after watching some of that, I attack what's on my plate with deeper dedication and vigor.

Think about the music that inspires you and why. It'll largely depend on your preferences and interests. I personally like watching the YouTube channels COLORS and NPR Music because they show musicians performing live. It inspires me to show-up more productively and actively in my own life. If these musicians can create such joy for the world, then I also want to give my full energies to bring readers the finest pieces of my work.