By Melissa Locker
Each product we feature has been independently selected and reviewed by our editorial team. If you make a purchase using the links included, we may earn commission.
Woman in Bed Looking at Phone
Credit: JGI/Tom Grill/Getty Images

What's the first thing you do when you wake up in the morning? For many of us, we grab our phones and check our email—even before we have coffee. If you recognize that action, you're not alone: according to Forbes, 66% of people check their email in the morning. While it seems like a convenient way to jumpstart the day while still lying in bed, according to some experts, checking email in the morning can actually harm your productivity.

Business Insider asked three productivity experts which of our daily work tasks are the biggest time wasters and they all said the same thing: email. Here's why: When you end the work day most of us have a sort of mental checklist of what needs to be done the next morning. There are calls to make, reports to finish, messages to return, files to update, etc. When you check your email, your to-do list can get shuffled around and what you knew you needed to get done gets shoved further down the list. For example, instead of finishing the report you were working on, you'll start replying to emails, solving problems, answering questions, adding more work to your pile, and generally responding to someone else's to-do list.

WATCH: Science Says People Who Are Always Late Are More Successful and Live Longer

"You are sacrificing one of the most productive periods of your day, the start, when you are fresh, alert, and not yet mentally fatigued to react to what everyone else wants from you versus using your focused energy to advance your goals," Carson Tate, author of Work Simply: Embracing the Power of Your Personal Productivity Style, told Business Insider.

If you dive into your inbox first thing in the morning, you may end up never completing the tasks on your own to-do list. The further you dive into your inbox, the less time you'll have for the work you prioritized yesterday, which can add to stress levels. Studies show that email is a major cause of stress in the workplace, with 92% of employees showing elevated blood pressure and heart rate when using email at work. That's part of the reason that Oprah favorite Julie Morgenstern titled her popular productivity book,Never Check Email in the Morning.

So when should you check your email? Most experts agree that it makes sense to give yourself the first hour of the day to do the tasks you laid out for yourself. Here's what some successful folks do in the first hour of their work day. After that, it's up to you. In The 4-Hour Workweek, Tim Ferriss suggests checking email just twice a day. In her book, Unsubscribe, author Jocelyn K Glei suggests setting aside no more than two or three blocks of 30 minutes a day for checking emails. If you're worried about missing an important email, services like AwayFind can monitor your inbox and get your attention when something notable arrives