Sleeping Apps: Can They Wake Up When Needed?

Sleep apps are designed to help users track and improve their sleep. They can monitor sleep patterns, provide insights into sleep quality, and offer features such as smart alarms and sleep schedules to help users optimize their sleep habits. However, a common concern among users is whether they will still receive calls when using these apps. This is especially important for those who are on-call or have jobs that require them to be available outside of regular working hours. While some sleep apps have a Do Not Disturb mode that blocks all notifications, users can usually customize their settings to allow calls to come through while still taking advantage of the app's sleep-tracking features.

Characteristics and Values

On-call work and sleep

On-call workers often experience sleep disruption due to the unpredictable nature of their work. This can have negative consequences on their long-term physical and mental health, as well as their performance the next day and immediately after waking up. When an on-call worker is woken up by a call, they may experience sleep inertia, which is a transitional state between sleep and wakefulness characterised by grogginess and reduced alertness and performance. This can last for up to an hour and has been implicated in workplace accidents, especially in high-stress and safety-critical situations.

To reduce the impact of sleep inertia, several countermeasures have been suggested, including the use of bright light, caffeine, and exercise. Caffeine, in particular, has been found to improve cognitive performance and reduce sleep onset latency when returning to sleep after being woken up. However, it is important to note that the impact of caffeine on sleep quality has not been extensively studied and may influence subsequent sleep.

While countermeasures such as natural waking, dawn simulators, and caffeine can be effective, they are only suitable when the worker has a planned sleep opportunity and known wake-up time. As on-call workers can be woken up at any time, these proactive countermeasures may not always be applicable. Instead, reactive countermeasures implemented upon waking may be more practical for on-call workers.

To manage sleep while working on-call, it is recommended to set up a sleep schedule and wind-down period, reduce distractions before and during bedtime, and use features like Sleep Focus on iPhones to filter out notifications and calls. Additionally, strategies such as prioritising sleep, maintaining a consistent sleep schedule, and creating a relaxing sleep environment can help improve sleep quality and reduce the impact of sleep disruption.

Sleep inertia countermeasures

Sleep inertia is the term used to describe the groggy feeling when you wake up. Sleep inertia can be caused by an increase in delta waves or high levels of adenosine, a nucleic acid compound found in the brain, upon waking. It is often experienced as 'grogginess' upon waking, and can also involve feelings of disorientation, drowsiness, and cognitive impairment. While the most severe symptoms typically last for 15–30 minutes post-waking, full recovery can take over an hour. Sleep inertia can negatively impact essential cognitive functions, such as reaction time, decision-making, memory, logical reasoning, and problem-solving.

Proactive Sleep Inertia Countermeasures:

• Waking naturally rather than to an alarm: Consistent wake-up times can help reduce morning sleep inertia.
• Using a dawn simulator: Gradually increasing light exposure can help simulate a natural sunrise and ease the transition from sleep to wakefulness.
• Caffeine before a short nap: Caffeine can improve cognitive performance upon waking and reduce sleep onset latency when returning to sleep. However, it is most effective when administered before sleep and may impact subsequent sleep quality.

Reactive Sleep Inertia Countermeasures:

• Bright light exposure: Investigations into light and temperature have shown promising results for improving subjective alertness.
• Caffeine: Caffeine is perhaps the most effective reactive countermeasure, although it is best taken before sleep.
• Exercise: Physical activity can help improve alertness and reduce the effects of sleep inertia.
• Cold air: Blasting cold air can help perk you up and improve alertness.
• Washing your face: Splashing cold water on your face can help you feel more awake and reduce grogginess.

It is important to note that reactive countermeasures upon waking may not be suitable for on-call workers who can be woken up at any time during their sleep period. In such cases, proactive countermeasures planned ahead of time may be more effective in reducing sleep inertia. Additionally, good sleep hygiene habits, such as a regular bedtime routine, a consistent sleep schedule, and limiting electronic device use before bed, can also help improve sleep quality and reduce the effects of sleep inertia.

Caffeine and sleep

Caffeine is a popular stimulant that promotes wakefulness and enhances performance. It is commonly consumed in the morning to boost alertness and throughout the day to ward off sleepiness. Caffeine is naturally found in many plants, including coffee beans, tea leaves, cacao pods, and kola nuts. It is also added to medications and energy drinks. While it can be an effective tool for improving alertness and performance, excessive or late caffeine consumption can interfere with sleep.

Caffeine affects the brain by blocking adenosine receptors. Adenosine is a sleep-promoting chemical that builds up in the brain during waking hours, making people feel sleepier the longer they have been awake. When caffeine blocks this process, people remain alert and vigilant. However, this interference with the natural sleep-wake cycle can disrupt sleep, especially when consumed in large amounts or close to bedtime.

Research has shown that caffeine consumption can reduce total sleep time and sleep efficiency, increase sleep onset latency, and decrease the amount of deep, slow-wave sleep, which is crucial for feeling refreshed the next day. These effects can lead to insomnia, anxiety, and headaches. It is recommended to avoid caffeine at least 8 to 13 hours before bedtime to ensure better sleep quality.

For on-call workers who need to perform immediately upon waking and then return to sleep, caffeine can be beneficial. Studies have shown that caffeine improves cognitive performance and helps people fall back asleep after being abruptly woken up. However, it is important to note that caffeine may impact sleep quality during subsequent sleep, and the effects of caffeine on sleep can vary depending on individual sensitivity, the timing of consumption, and the dose.

To optimize sleep while using a sleeping app, it is advisable to avoid caffeine close to bedtime and be mindful of the potential impact on your sleep quality and duration. While a sleeping app may not wake you up when a call is received, caffeine's effects on alertness and wakefulness could influence your sleep patterns and overall restfulness.

Sleep schedules

Sleep is a vital component of human health, and the amount of sleep a person needs changes with their age. The quality of sleep and how rested you feel afterward is as important as how much sleep you get. While 7 to 8 hours a night is recommended for most people, children and teenagers need more. Older people tend to do fine with less sleep at night but may still need about 8 hours of sleep over a 24-hour period.

There are three types of sleep patterns: monophasic, biphasic, and polyphasic. A monophasic sleep pattern is the "normal" sleep pattern, where an individual sleeps once per day, typically for 8 or so hours a night. This became the norm during the industrial revolution's longer-than-normal working hours.

A biphasic sleep pattern is when someone sleeps twice per day, sometimes referred to as a siesta sleeping pattern. Some cultures engage in biphasic sleep patterns, sleeping at night and during a daily afternoon nap.

A polyphasic sleep pattern involves breaking traditional sleep schedules into multiple shorter periods. Polyphasic sleep schedules are not for everyone and may cause sleep deprivation. They can vary in duration and timing to accommodate irregular work schedules. Polyphasic sleep schedules involve sleeping over more than two sleeping periods each day. These periods could be quick nap breaks throughout the day balanced with a reduced time asleep during the night.

There are several popular polyphasic sleep schedules:

• Uberman Sleep Schedule: Six 20-minute naps are spaced evenly throughout the day, totaling two hours of sleep per 24-hour period.
• Everyman Sleep Schedule: This schedule includes sleeping for three hours during the night and supplementing with three 20-minute naps throughout the day, for a total of four hours of sleep each 24-hour period.
• Triphasic Sleep Schedule: Three short sleep periods happen after dusk, before dawn, and in the afternoon, providing a total of four to five hours of sleep per 24-hour period.

Anecdotal reports from followers of polyphasic sleep schedules often include claims of increased productivity, alertness, and ability to learn and retain information. However, credible evidence to support these claims is lacking. It may be that polyphasic sleep schedules feel more productive simply because the sleeper has more time, rather than more energy, to get tasks done.

If you are experiencing insomnia, which is difficulty falling asleep or staying asleep, you can relieve it by making a few simple lifestyle changes. Find ways to manage stress by learning relaxation techniques such as guided imagery, listening to music, or practicing yoga or meditation. Develop a sleep routine by waking up and going to bed at the same time every day. Make sure your sleep area is quiet, dark, and at a comfortable temperature. Avoid caffeine or alcohol in the evening and heavy meals at least 2 hours before going to sleep.

VoIP Push notifications

VoIP, or Voice over Internet Protocol, is a service that allows users to make and receive phone calls over an Internet connection rather than through a device's cellular services. VoIP push notifications are a way to update a VoIP application in the background state and wake it up when a VoIP call is received.

Before iOS 8, VoIP apps needed to maintain a persistent connection with the server to receive calls using an Internet connection, which was problematic in terms of battery life and app crashes. With the introduction of iOS 8, Apple introduced PushKit, which improved battery life, performance, and stability for messaging apps. PushKit notifications are never presented to the user and are instead delivered with high priority directly to the app, which is woken up only when VoIP pushes occur.

To configure your app to receive VoIP push notifications, you need to link to the PushKit framework in your app delegate, create a PKPushRegistry object, and set its delegate to self to register to receive VoIP pushes. Next, implement a delegate method to handle updated push credentials. If your app receives both standard and VoIP push notifications, it will receive two separate push tokens, and both must be passed to the server to receive notifications. Finally, set up a delegate method to process pushes. If your app isn’t running when the push is received, it will be launched automatically.

Frequently asked questions