Exercises: Healthy usage habits

State three effects that spending many consecutive hours on your cell phone or computer can have on your health, and propose a simple guideline to prevent each one.

Explain why it is not a good idea to use your phone in bed just before going to sleep and propose two specific alternatives for the last half hour of the day.

The figure represents a study workstation in front of a screen.

Indicate the approximate recommended distance between eyes and screen (the gap ?) and explain two more guidelines, visible in the scene or deducible from it, that help protect your eyesight and back.

Explain what the 20-20-20 rule for resting your eyes consists of (every twenty minutes, look for twenty seconds at something about six meters away) and what specific problem it relieves.

Explain what "text neck" is, why tilting your head far forward towards your phone multiplies the weight supported by your neck, and describe two ways of holding your phone that reduce this.

Eating while looking at your phone has been linked to eating more and less healthily. Explain what role attention plays in the feeling of satiety and propose a simple rule for mealtimes at home.

Explain what blue light from screens is, how it interferes with melatonin and sleep, and which phone settings (night mode, brightness, scheduled times) help reduce its effect at night.

State three physical signs that you have been playing or looking at the screen for too long at a stretch (dry eyes, neck pain, heavy head...) and explain what should be done as soon as each one appears.

The digital well-being report on a cell phone summarizes average daily use: $2\ \text{h}\ 30\ \text{min}$ of social media, $1\ \text{h}\ 45\ \text{min}$ of video and $45\ \text{min}$ of gaming. Express each time in hours as a decimal (remember that $30\ \text{min} = 0.5\ \text{h}$), calculate the daily total and the weekly total, and determine how many hours per week would be gained for physical activity if that screen time were halved.

Describe how you would set up an ergonomic study workstation at home: height and position of the screen, chair, keyboard and lighting. Explain what health problem each decision prevents.

A friend plays online until two in the morning on weekdays and arrives at school having barely slept. Explain what immediate and long-term consequences this habit can have and what specific change you would propose to them to start with.

The figure divides the twenty-four hours of a student's day between sleep, school and leisure screen time, as shown in the figure.

Calculate how many hours remain free (the sector marked with ?), assess whether this distribution is healthy, and propose an alternative distribution, using numbers that also sum to $24\ \text{h}$, explaining what it improves.

Many games offer "loot boxes" with random rewards. Explain why unpredictable rewards are more addictive than fixed ones, how this mechanic resembles slot machines, and what sign indicates that the game is designed to keep you playing.

Studies on attention show that the mere presence of a phone on the table, even if silent, reduces concentration. Explain why this happens and design your "study mode": what you do with your phone, notifications and breaks to perform well.

Propose three ways to use technology to benefit physical health (workout apps, step challenges with friends, sports technique videos) and one precaution or limit for each, so that they remain healthy.

A friend compares themselves to the "perfect" bodies seen on social media and has started skipping meals. Explain what is artificial about those images (filters, angles, editing, picking the best moment), what risks their health faces, and how you would speak with them and with a trusted adult.

An app measures your "screen time" while rewarding you with badges and streaks for opening it every day. Analyse the contradiction between its stated well-being objective and the techniques it uses to hook you, and evaluate whether this type of tool really helps reduce usage.

Based on the following weekday usage log of a 3rd year ESO student (4.2 h of daily screen time: 2.5 h on social media, 1.2 h on video games, and 0.5 h on schoolwork; last connection at 00:30 from bed; recurring morning sleepiness):

1. a) Design a realistic healthy use plan for their Monday-to-Thursday afternoons. It must redistribute digital leisure time and establish two concrete measures (one regarding device configuration and another regarding physical space organization) to ensure disconnection.
2. b) Justify why the mobile phone should not be charged in the bedroom from the perspective of sleep quality and nighttime impulsivity.
3. c) Define two measurable indicators (one quantitative and one qualitative) to evaluate after one month whether the plan has been successful.

The weekly digital wellbeing report issues the same red alert ("Excessive use: 3.5 h daily") for two students. Lucía spent that time programming an application in Scratch and editing a school podcast; Dani spent it scrolling through short videos on a social network.

1. a) Technically refute the report's conclusion ("Both present the same digital health risk") by justifying the cognitive, emotional, and mental fatigue differences between active and passive use.
2. b) Propose two alternative metrics or criteria that a digital wellbeing tool should incorporate to reflect the real impact of screen time beyond total minutes.

A student wants to test whether using her mobile phone in bed reduces her sleep quality. For one week, she uses her phone until falling asleep, and the following week, she turns it off one hour earlier, but stays up late reading notes under intense light. Noticing no improvement in her grades or in her morning fatigue, she concludes: "I have proven that screens have no influence whatsoever on rest".

1. a) Identify two methodological flaws in her experiment (uncontrolled variables or sources of bias).
2. b) Redesign the experiment for two weeks: define the independent variable, two measurable dependent variables (at least one quantitative), and which factors must be kept constant for the data to be reliable.

A video platform replaced the manual "Watch next" button with autoplay featuring a 3-second countdown. Following the change, the average time spent on the platform increased by 35 %, but user ratings of wellbeing and satisfaction dropped significantly.

1. a) Explain this phenomenon using the concepts of "design friction" and "choice architecture" versus conscious self-control.
2. b) Design two technical or interface modifications that return conscious control to the user and make "the time to stop" easier without simply resorting to forcing the app to close.

A school is debating a total ban on cell phones. Argue from the perspectives of health, social cohesion and learning for and against it, and propose a realistic compromise rule (stored away upon entry, specific educational use), defending why it would work better than a total ban or total freedom.

A sports app rewards training every day with "streaks", the same mechanic used by social media. Analyse why in one case it is considered healthy and in another dangerous, where the line is drawn (training when injured, anxiety if a day is missed) and what difference there is between consistency and dependency.

Evaluate weekend "digital detoxes" (leaving your cell phone behind for two days) as a solution to bad habits: what they can offer, why their effect is usually short-lived and what daily habit change, more modest but permanent, you would suggest instead.