A Long Hot Soak versus the Gym

Japan has the third largest physical activity economy in the world, at US$21bn ⁽¹⁾. Active participation is a relatively high 70%. The Global Wellness Institute also estimates that average per participant spend (including enabling supplies) is US$495 versus US$582 in Europe and $1,345 in North America.

Despite this Japan has 36% inadequately active. ⁽²⁾ This reflects the country’s prosperity. High-income countries average 37%, Middle-income countries average 26%, and Low-income countries average 21%.

Is there an alternative to the gym?

The health benefits of physical exercise have been studied for 3/4 decades. Academic research is now investigating passive heating, “thermal therapy”, and early results indicate comparable benefits.

Studies have found that passive heating can induce numerous health benefits, such as improvements to cardiorespiratory fitness, vascular health, glycemic control, and chronic low-grade inflammation. ⁽³⁾

The table below summarizes the research program to date. Research into the commonalities of the underlying mechanisms is ongoing.

The table is formatted to be read in landscape:

Summary of Chronic Adaptions to Exercise (Ex) and Passive Heating (PH)

BI: Beneficial Increase, BD: Beneficial Decrease, NE: No Effect, ME: Mixed Evidence, ?: Lacking Evidence

Cardiorespiratory fitness	Ex	PH	Vascular health	Ex	PH	Cardiometabolic health	Ex	PH
VO(2max)	BI	BI	Endothelial function	BI	BI	Fasting glucose concentration	BD	BD
Left-ventricular function	BI	?	Peripheral arterial compliance	BI	BI	Fasting insulin concentration	BD	BD
Left-ventricular structure	BI	?	Peripheral arterial wall thickness	BD	NE	Fasting lipid concentrations	BD	BD
Plasma volume	BI	BI	Central arterial stiffness	BD	BD	Resting CRP, TNF-α, IL-6 concentration	BD	ME
Mitochondrial biogenesis	BI	ME	Central arterial wall thickness	BD	BD	Body mass	BD	NE
Capillarisation	BI	BI				Resting blood pressure	BD	BD

Note: The health benefits of passive heating and aerobic exercise: To what extent do the mechanisms overlap ⁽³⁾

Source: Paper noted above, Conceptasia, June 2021

Fortunately, Japan has the most extensive network of thermal springs in the world, ⁽⁴⁾ further facilitating a long hot soak as an alternative/complement to time spent in the gym.

References:

1. Move to be well: The Global Economy of Physical Activity, by Global Wellness Institute, October 2019
2. Asian Development Outlook 2020, Update, Theme chapter: Wellness in Worrying Times, by ADB, September 2020, data from the The Lancet – Worldwide trends in in sufficient physical activity from 2001 to 2016: a pooled analysis of 358 population-based surveys with 1.9 million participants. October 2018
3. The health benefits of passive heating and aerobic exercise: To what extent do the mechanisms overlap? by Tom Cullen, Neil D. Clarke, Matthew Hill, Campbell Menzies, Christopher J. A. Pugh, Charles J. Steward, and C. Douglas Thake, September 2020
4. J-Wellness 2020: The economics, career options, and investment opportunities, chapter five, by Peter Eadon-Clarke & Yoriko Soma, August 2020