There are things you want to achieve in this life. Say, you want to write a novel, or complete a half-marathon, or start getting up at 6am. A first blush of excitement and enthusiasm can power our motivation. Eventually — and perhaps sooner than we think — enthusiasm wanes and we need a little more help accomplishing our goals. How do you keep hitting your word count and logging your miles when you've lost the spark? Here's how to keep trucking when the going gets tough.

Tackle your toughest task first

Given that energy is highest in the morning, this tends to be a good time to take care of our most difficult tasks. Knocking the most onerous item off your to-do list first thing may also make the rest of the day seem like a breeze, writes Brian Tracy in Eat That Frog (The book's title comes from a Mark Twain expression: "If you eat a frog first thing in the morning that will probably be the worst thing you do all day.").

...Or tackle your tiniest

On the other hand, studies have shown that you can trick your brain into increasing dopamine levels by setting and achieving even the most minuscule goals. Tim Herrera of the New York Times calls it "micro-progress" and "the magic of just getting started."

Eliminate distractions

Internet off. Phone locked up. Use apps that block you from your biggest distractions if you must, but set yourself up for success by barring access to some of the most offensive time-sucks.

Act as if

Feeling low-energy, blue, and ineffective? Imagine that you're feeling high-energy, upbeat, and productive and act accordingly, suggests Psych Central. This "fake it till you make it" method is used in Alcoholics Anonymous in which you act as if something we're already true. Act as if you're super stoked to get out of bed, can't wait to get to the office, or would totally rather hit the gym than happy hour after work. When you don't give yourself the time to talk yourself out of something, you may actually find that you do really enjoy that cup of coffee, or listening to that podcast on the way to work, or sweating out your aggression in a 6pm spin class.

Give yourself breaks

A study published in Nature Neuroscience found a 20 to 30 minute nap can halt a deterioration in performance, and an hour-long nap can even reverse that deterioration.

Try stepping away from your desk. To do our best work over the long term, we need "opportunities for restocking [our] mental energy," Ron Friedman, founder of ignite80, the consulting firm, and the author of the book, The Best Place to Work: The Art and Science of Creating an Extraordinary Workplace, told the Harvard Business Review. Duck out for a yoga class or have lunch away from your desk. "Stepping away from your computer gets you out of the weeds and prompts you to reexamine the big picture," he said. "It's often in the intervals between thinking really hard about a problem and then stepping away that solutions becomes apparent."

You may also try working with on-off intervals, such as the Pomodoro method, or breaking for 15 minutes after every 45 minutes of work.

Build a team

A team can help hold you accountable and offer support when motivation is flagging. Enlist a buddy to share your goal of running a half-marathon or saving $50 a week. Hold yourself accountable for paying for things like exercise classes in advance so you'll be more motivated to go.

Visualize how you'll feel after

You know you'll feel strong and fierce after your three mile jog, and that a weight will be lifted after you finally call the insurance company. When you don't feel like doing something, take a moment to vividly imagine what the results of the task will be. That may be enough to get you out of your slump.

Reward yourself

You accomplished your micro-goal of the day, then your weekly goals, and finally the big finish. Be sure to give yourself rewards along the way and be sure to actually give them to yourselves. You wouldn't trick a child or a dog out of the treat you promised; don't do it to yourself, either.