The sunny summer months are a perfect time to increase your productivity at work without spending an exorbitant amount of time there.

In the U.S., we tend to correlate longer working hours with greater productivity and efficacy in a business.

However, spending more time at work may not really be helping us. Consider a few studies:

• In a study of consultants, managers couldn't distinguish "between employees who actually worked 80 hours a week and those who just pretended to" (HBR).
• "Employee output falls sharply after a 50-hour work-week, and falls off a cliff after 55 hours — so much so that someone who puts in 70 hours produces nothing more with those extra 15 hours" (IZA).
• White-collar professionals who worked 10 hours a day were 60% more likely to have heart problems than those who worked seven hours a day (UCL).

So it's not just a matter of productivity — it's a matter of health.

Consider these tips to get more done at work in fewer hours, so you can get out and enjoy the summertime. For more productivity ideas, check out our interactive infographic 10 Scientifically Proven Tactics to Stay Productive.

1. They set aside time for deep work.

First, understand what "deep work" means for your role. Cal Newport, author of the NYT bestseller Deep Work, explains that “deep work is what produces real value. Deep work is what allows you to improve your skills rapidly. Deep work is what allows you to produce things that are rare and valuable. And in the end, that’s really the key currency in our in our current economy. The stuff that you can do that’s really valuable and not easily replicable is the only thing that is going to move the needle.”

So, what does this look like in practice? Deep work usually means that you're heads-down in a project that requires your utmost concentration. Set aside a block of at least 90 minutes without meetings each day so you can accomplish this all-important work.

2. They create a "must do" list for each day.

Personally, I like to start my workdays with a list of must-dos instead of to-dos. This lets me first worry about all the must-do items before I begin to tackle the "maybe today, maybe tomorrows." My work day is often rerouted from what I thought it would be — by random meetings, semi-urgent emails, and chat messages requesting my help. So if I don't start on the must-dos until 3 or 4 p.m., there's no way I can finish work at a decent time.

That's why I aim to start with only 1-2 must-dos for each day, so I'm only leaving work after I accomplish the truly necessary stuff. For those of us who also suffer from a touch of perfectionism, this also helps decrease the self-expectation of finishing a massive task list every day.

3. They seriously don't multitask the important stuff.

By now, you probably know that multitasking isn't really a thing. But even frequently switching tasks can hamper our productivity by 40%. Task-switching can feel like a way of life in many high-stress professional jobs (phones are ringing; chats are coming in; emails are popping off), but do your best to switch off as many tasks as you can so you can truly concentrate and make fewer mistakes.

In general, switching from task to task is only going to introduce errors into your work as you lose your train of thought. So while it may be fine to answer a quick email on your phone while you're walking to a meeting, it's probably not a good idea to edit an important document while talking on the phone.

4. They turn off Slack, text messages, email, or whatever ails them for a designated time.

Of course, you need to be available when your teammates need you. But that doesn't mean you need a distracting alert popping up every time someone from the office just wants to say hey.

When you're really angling to complete a project by a deadline (or get off work on time), turn off these distractions until you're finished. You can always let your coworkers know the plan so they're not surprised when you don't immediately reply.

5. They hide their phones.

For most of us, our smartphones are always lurking nearby, providing ample distraction via Facebook, Instagram, Snapchat, stock market updates, and more. Turn off the visual cue that your phone offers for distraction ("Hey, check me again!") by simply putting it away during prime working hours.

6. They block off time on their calendars when they have to stop working.

Whether it's putting a virtual block on your calendar for after 5:30 p.m. or scheduling a daily walk with a friend, you'll get more done if you have an actual deadline for when a day's work must be completed. If you let work hang into the early evening and beyond, you'll never let your sense of urgency kick you into overdrive to complete a project.

7. They create external deadlines.

Self-imposed deadlines are better than nothing, but external deadlines are the true productivity boosters. In one MIT study, self-imposed deadlines improved performance, but people typically didn’t set their own deadlines to really push themselves. In other words, we tend to go easy on ourselves. So to truly increase your productivity, set deadlines for key projects — then tell others about those deadlines to hold you accountable. This strategy will definitely help you get those projects finished without working until 7 p.m. on a summer Friday.

8. They make 15- or 20-minute meetings the norm.

Think about how much time in meetings is wasted. You probably have to get approval from your manager for a $500 expense... but you can call a one-hour meeting with 20 people and no one notices. Time is money, and we can often spend the first 5-10 minutes making small talk or introducing the topic because there's no sense of urgency.

Instead, focus on making the most of everyone's time by scheduling shorter meetings (say, 15-20 minutes) and only going longer if the subject matter truly warrants it. Attendees will get to the point more quickly once they know there's an imminent ending.

9. They get meeting agendas and goals ahead of time, or else, they don't attend.

A meeting without an agenda and clear goals is a meeting that's going to take too long. If someone calls a meeting and can't be bothered to explain what it is ahead of time so you can come prepared with ideas, it may not be worth attending.

10. They stop reading blog posts about productivity and get to work.

Of course, I'm half-joking. I'm happy to have you reading my blog post. But the more time you spend reading about productivity, the less time you'll have to actually complete whatever it is that you need to do today. And the less time you'll have to enjoy a beautiful summer evening. So get and stay focused, and, like Nike always reminds us, just do it.

Are you a true procrastinator? Or you're tackling a massive project? There's lots more productivity advice where that came from, and we all have our own working styles. Explore our interactive infographic 10 Scientifically Proven Tactics to Stay Productive for even more ideas — so you're sure to find something that works for you.