[boxcarr]

From the blog post:

> Interestingly, those who felt the greatest boost in mood also experienced the biggest drop in heart rate variability.

A drop in HRV isn't generally good. So I check the paper, and found this:

> No significant changes were found in heart rate variability or resting heart rate over the course of the study in either of the groups (Figures 4C and 4D)

There was a reduction respiratory rate for those an increase in daily positive affect. Bottom line, unclear if this particular study points to a positive health outcome other than feeling happier.

[curiouska]

From the paper:

Interestingly, change in respiratory rate was negatively correlated with change in daily positive affect (Figure S5; r = - 0.24, p < 0.05), suggesting that participants who showed the highest reduction in respiratory rate also showed the highest daily increase in positive affect over the course of the study (Figure S5).

[curiouska]

But as you said, the main finding reported was an increase positive affect.