Deborah KayBy Deborah KayJune 13, 20226 Minutes

Optimising my deep sleep

Deep Sleep Time

Over the last three years, I doubled the amount of deep sleep that I get – on a good night, I get between 2:20 and 2:40 hours of deep sleep. Here’s what I did.

I started tracking my sleep with the Oura Ring in June 2019.

The Oura is meant to be the best sleep tracker in the market with near-perfect for resting heart rate (r² = 0.996) and extremely high for heart rate variability (r² = 0.980) when compared to a medical-grade ECG device.¹

In addition, the Oura was found to be 76-78% accurate for 4-stage classification (light, deep, REM, and wake) Oura was 92-93% accurate for 2-stage classification (sleep, wake) Oura’s latest sleep staging algorithm outperforms older versions, especially for younger adults.²


Analysing Oura trend data

Looking at my Oura trend data from 2019 to 2022, the biggest statistical correlations are:

Deep Sleep and Average RHR

  • Strong negative correlation between deep sleep and average resting heart rate (0.78)
  • Strong negative correlation between deep sleep and lowest resting heart rate (0.75)
  • Strong positive correlation between deep sleep and HRV (0.75)

Both are general health and recovery metrics, hence I will conclude that improving my deep sleep has to be correlated with improving my overall health and recovery.


What I did

  • Cutting alcohol consistently over years
  • Sleeping in very cold room. My Ooler (mattress cooling pad) made a huge difference to my sleep scores
  • 3 months of HRV breathwork (with no alcohol) also made a huge difference to my sleep scores
  • Consistent cardio and improving overall health
  • Reducing stress levels (via sauna, yoga, meditation and eliminating annoying work and people from my life)
  • Good sleep hygiene (consistent bed time, not picking up phone during wake ups)
  • Recently I put my phone on airplane mode when I sleep. Not sure about EMF but mentally it helps me not pick the phone up when I wake up at night
  • No late food which impacts digestion
  • No caffeine after 11am and no more than 1-2 coffees a day
  • Magnesium Threonate (good for brain and sleep) – see Supplements

It’s also interesting to see the big drop in RHR in February 2021. I go dry every year in the month of February but in 2021, I also did 100 days of HRV breathwork using the HRV4Biofeedback app. This seems to have made a big difference in my resting heart rate and deep sleep!


What did not work

  • Blue light blockers – it never made a difference
  • Sauna bathing also did not appear to have a big impact on that particular night’s sleep, though I strongly believe that sauna bathing is good for overall reduction in stress levels so may contribute to better sleep in the long run


Other points to note

If you are comparing your sleep scores to mine using a different sleep tracker (Fitbit, Garmin etc), sleep trackers are notoriously inaccurate for sleep staging so I wouldn’t fuss about absolute numbers. Just for illustration, check out the difference in sleep staging as measured by my Oura vs my Garmin Venu2S.

Oura vs Garmin Sleep Staging


I take Magnesium Theorenate (this is the best version of magnesium to boost brain levels of magnesium for sleep) and Zinc to help with my sleep. If I am very stressed and I feel that my cortisol is elevated, I will also take Ashwagandha (must be KSM-66 – the most clinically studied ashwagandha extract), an adaptogen that is known to reduce cortisol.

However, I don’t take Ashwagandha every night as I’ve heard anecdotal evidence from the Oura Ring Facebook group that you can build a tolerance to it, and that your sleep may be affected if you stop after prolonged use.


Brands I’m taking:



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