Adaptive Stress Response: The Hot Yoga Study

This is a small scale intervention pilot study which is aimed at characterizing "hormesis" or the "adaptive stress response" in a small cadre (n = 28) of women aged 30-45 years performing moderately vigorous physical activity, Bikram Yoga, in a hot environment, simply referred to as "Hot Yoga". The primary question is:How does the body physiologically adapt to performing moderately vigorous exercise in a hot environment?

The hypothesis of this study which underlies the primary question is that a protective and health-promoting adaptive stress response can be induced in living humans through exposure to mild heat stress and moderately vigorous physical exercise while practicing hot yoga. The central premise is that a combination of environmental stressors during each hot yoga session will induce changes in molecular networks and metabolism that will enhance physical/mental health and physiological resilience.

Primary, secondary and tertiary study endpoints:

Characterize the physiological changes brought on by the adaptive stress response using an "omics" approach. Lipidomics and metabolomics will be used to identify changes in small molecule species found in circulating plasma that are associated with the physiological changes the investigators anticipate will occur with the adaptive stress response.

Characterize the adaptive stress response by measuring the changes in the inflammatory response using common inflammation biomarkers: C-reactive protein (CRP), Tumor Necrosis Factor Alpha (TNF-alpha), and Interleukin-6 (IL-6). A complete blood count (CBC) w/Differential assay will also be performed at baseline and after the last Hot Yoga practice to assess any changes in blood components (red blood cells [RBC], white blood cells [WBC], platelets, etc.) that may have occurred in response to the intervention. In addition, the investigators will use buffy coat to assay all WBCs and will perform both typing and counting of WBCs to assess changes relevant to the adaptive stress response. Finally, buffy coat will be used for DNA isolation to genotype for single nucleotide polymorphisms (SNPs) that are related to the adaptive stress response.

Characterize the acute effect that exercising in a hot environment has on emotional stress and well-being using:

Positive and Negative Affect Schedule - Short Form (PANAS-SF) PROMIS - Global Health Scale

Assess long-term effects of the intervention on emotional stress and well-being using a battery of questionnaires that include Warwick-Edinburgh Mental Well-being Scale (WEMWBS) Patient Health Questionnaire (PHQ-9) Generalized Anxiety Disorder (GAD-7) Perceived Stress Scale (PSS)

Importantly, circulating levels of small molecule metabolites will be determined with metabolomic and lipidomic analyses utilizing HPLC-tandem mass spectrometry. Levels of blood inflammatory and stress biomarkers interleukin-6 (IL-6), Tumor Necrosis Factor Alpha (TNF-α), and C-reactive protein (CRP) will be measured utilizing standard enzyme linked immunosorbent assays (ELISA). These assays may be performed in-house or at Sonora Quest Laboratories.

The investigators will implement the use of biostatistics, bioinformatics, and other statistical methods to analyze, interpret, and express the found data and dependent upon the findings, then use the data as the base for grant funding to conduct a full scale clinical trial testing the aforementioned hypotheses.

Inclusion criteria

• Healthy, non-menopausal women between the aged 30 to 45 years (≥30 years and ≤45 years)
• Not pregnant/not planning to get pregnant during the study duration
• Have not previously participated in hot yoga in the last 12-months
• Able to give informed consent and be willing to participate for the entirety of the study
• Agree not to take interfering medications (stated in 'Exclusion Criteria' section below) during the duration of the study
• Agree to allow samples to be stored for future use
• Pass the preliminary health screening
• Answer no for every question on the Physical Activity Readiness Questionnaire (PAR-Q ) during preliminary screening

Exclusion criteria

1) Menopausal 2) Answered "Yes" to any question on the Physical Activity Readiness Questionnaire (PAR-Q) 3) Currently lactating 4) Currently pregnant or plan to get pregnant within the duration of the study 5) Has participated in hot yoga within the last 12-months 6) Used tobacco products (smoked, smokeless, electronic) within the last six months 7) Have diabetes, cancer, heart attack or vascular surgery within the past year, be diagnosed with heart disease, high blood pressure, history of stroke, atherosclerosis, asthma, multiple sclerosis or chronic joint disease 8) Have gallbladder disease or had gallbladder removed 9) Have any of the following health conditions:

• fasting Triglycerides greater than 150 milligrams/deciliter
• Blood pressure greater than 130/90
• Body Mass Index equal to or greater than 30 or less than 19
• Fasting glucose greater than 125 milligrams/deciliter.
• Having a pacemaker or a defibrillator 10) Taking any of the following drugs:
• Taking greater than 100 mg aspirin/day
• Taking non-steroidal anti-inflammatory drugs or oral corticosteroids
• Taking monteleukast-type of allergy medications
• Use of statins, niacin or fibrates or other lipid lowering medications