Summary of "Cách Ngủ Ít Mà Không Mệt"

Key Wellness Strategies and Productivity Tips for Sleeping Less Without Feeling Tired

Understanding Sleep Cycles

Sleep occurs in cycles of approximately 90 minutes. Each cycle consists of 5 stages:

Stage 1 (Lull): Falling asleep.
Stage 2 (Light Sleep): Body starts relaxing; about 50% of total sleep.
Stage 3 (Deep Sleep): Less than 10% of sleep; restorative.
Stage 4 (Very Deep Sleep): Deepest rest for organs.
Stage 5 (REM Sleep): Active brain stage; eyes move, limbs paralyzed.

A full night’s good sleep usually consists of about 5 cycles (7.5 hours).

Why We Feel Tired Upon Waking

Waking up during deep sleep stages (especially Stage 4) causes fatigue, irritability, and panic because the body is not ready to wake. The ideal wake-up time is at the intersection between the end of Stage 5 (REM) and the beginning of Stage 1 of the next cycle when the body is prepared to wake.

Formula to Calculate Optimal Wake-Up Time

Wake-up time can be calculated as:

Wake-up time = Bedtime + (1.5 hours × number of sleep cycles) + time to fall asleep (average 14 minutes)

Examples:

Bedtime at 10:00 PM Wake-up time = 10:00 PM + 7.5 hours + 14 minutes ≈ 5:44 AM
Bedtime at 1:00 AM (for 3 cycles, minimum recommended) Wake-up time = 1:00 AM + 4.5 hours + 14 minutes ≈ 5:44 AM

Adjusting Sleep Cycles Based on Wake-Up Needs

Minimum of 3 cycles (~4.5 hours) to avoid extreme tiredness.
Maximum of 6 cycles (~9 hours) for those needing more rest.
If you must wake up early after going to bed late, reduce sleep cycles but still aim to wake at the cycle boundary.

Additional Tips

Avoid hitting snooze or lying back down after waking, as this can cause you to enter a new sleep cycle and wake up tired.
Train yourself to wake up immediately and get out of bed.
Understand that 8 hours of sleep is not a universal requirement; individual needs vary.
Use this knowledge to optimize sleep and reduce fatigue, especially when staying up late.

Encouragement for Sharing

Share this knowledge with friends and family to help them avoid morning fatigue and improve daily mood and productivity. Being well-rested positively affects relationships and work performance.

Presenters / Sources

Presenter: Web5ngay channel (Vietnamese business and self-improvement educator)
Source of sleep cycle methodology: Westlife company (referenced from an article on Telegraph.co.uk)