The Mattress Experiment: What Actually Changed

I have slept on four different mattresses since beginning my sleep optimization protocol. Three were purchased specifically for the sleep improvement purpose. One was the mattress I had before this process began. Here is the honest accounting.

Mattress 1 (Original, 2019-2022): A mid-range memory foam mattress from a now-discontinued brand. This was the mattress I slept on when I first became aware of the sleep problem. Whether the mattress contributed to the problem, I cannot determine — I don't have pre-mattress baseline data. It has been replaced. The replacement data is what I have.

Mattress 2 (Purple Original, 2022-2023): I purchased the Purple Original based on its temperature-neutral claim, which my data suggested might be relevant — my body temperature variability showed a pattern Dr. Chen noted as potentially correlated with certain types of sleep disruption. The Purple's hyper-elastic polymer grid is temperature neutral in ways standard foam is not.

Data after 90 days on the Purple: average wake events decreased from 3.4 to 2.9. Sleep onset latency decreased from 35 minutes to 31 minutes. HRV improved slightly. I noted these as improvements. I also noted that "improvements to a problematic baseline" is not the same as "the problem is solved." My readiness score average on the Purple: 67. The number was moving in the right direction.

Mattress 3 (Casper Original, 2023-2024): I wanted a comparison point. The Casper is a standard foam mattress with zoned pressure relief. It cost less than the Purple. The data after 90 days: performance approximately equivalent to the Purple in most metrics, slightly worse on temperature-related wake events (which I attributed to the less temperature-neutral foam). I reverted to the Purple.

Current state: Eight Sleep Pod 4 cover on the Purple mattress. This combination produced the largest improvement I've measured. The Eight Sleep data is in a separate review.