

You might find sitting tall comes easily in the morning, then by late afternoon you’re sinking lower and lower in your chair. That’s very common. Your muscles have been working all day, and your energy naturally dips. A few small changes can help you stay comfortable through the end of the day.
Research on office workers doing long stretches of computer work found that their heads and necks gradually bent further forward over time. As the day goes on, the muscles that hold you upright tire, and your focus on the task means you notice less.
Rather than relying on willpower, you could plan for it:
By the afternoon, it often helps to use your backrest more. Sitting all the way back, with your lower back supported, lets you stay upright without your muscles doing all the work.
Many people find that a short walk or a few minutes outside in daylight gives them a lift. Feeling more alert tends to make sitting tall easier too.
Set one reminder for mid-afternoon, and when it goes off, do your 10-second reset and stand up for a minute.