Direct and Cross Effects of Adaptation to Systemic Hyperthermia: Impact on Quality of Life, Neurohormonal and Psychophysiological Human Status

Hyperthermic Fitness Treatment (HFT) is proved in many applied and clinical trials to be a helpful tool for enhancing thermal acclimation, physical tolerance and endurance, improving cardiovascular dysfunctions, normalizing metabolic status and body weight in patients with chronic non-infectious diseases and in aged healthy individuals. Clinical effects of hyperthermia acclimation or repeated sauna's sessions were investigated in series of well-designed placebo-controlled studies at different cohorts of Bronchial Asthma (BA), Chronic Obstructive Pulmonary Disease (COPD), Cardiovascular Disease (CVD) Metabolic Syndrome and Obesity (MS-O) patients, qualified professional sportsmen and healthy volunteers.

Effects of sauna bathing and hyperthermic treatments (acclimation to systemic, whole body dosed hyperthermia, which leads to core temperature increase on 2,0-2,5oC) are accurately described in well-controlled medical studies, performed by experienced researchers imposing different protocols (from 1 session lasting 15-20 min, daily 1 week up to 2 sessions per day, 3 weeks).

The generalized result of the most trials suggests adaptation to hyperthermia (sauna bathing sessions) is accompanied by a multi-faceted molecular, cellular, organic and systemic, organismic responses - by progressively increased resistance to thermal stressors, increased bronchial conductivity and pulmonary ventilation, sweating; stimulated activation of neuro-humoral and cardiovascular systems, boosted microcirculation and, as a consequence, providing more efficient transport and utilization of O2 by body tissues, resulting in increase of exercise tolerance, physical activity, normalization of appetite, balancing thermogenesis and heat release.

Mechanisms underlying the described clinical effects are partially connected with increased production of some neurotransmitters, hormones and peptides, among them - Brain derived neurotropic factor (BDNF), Somatotropin (Human Growth Hormone - HGH), Heat Shock Proteins family as cell signaling pathways inducers etc.

In spite of difference in study design, protocols, and hyperthermic mashines - devices, it is safe to make the conclusion that periodic individually adapted hyperthermic sessions are capable to induce haematological, neuro-humoral, cardiorespiratory and antioxidant adaptation to provide pathogenetic treatment and rehabilitation of patients with chronic non-infectious diseases.

Enhanced stress resistance and improved oxygen transfer/utilization are basic mechanisms whereby the organism increases its resistance to any physical and environmental stressors and to variety of pathogenic factors.

The described Hyperthermic Fitness Treatment (HFT) method is safe, has no significant complications or adverse side effects and is generally very well tolerated by sportsmen, healthy persons and different clinical patients' groups.

Inclusion criteria

• Outpatients, young healthy volunteers
• Age > 19 years (20 - 30)
• Gender: male
• Healthy state (no chronic noninfectious diseases, documented by medical check-up results, obtained in 1-2 months before, not later), mobility (absence of orthopedic problems), satisfactory level of fitness
• Ability to perform activities of daily living
• Ability to attend all treatments and clinical-laboratory measurements
• Signed informed consent form

Exclusion criteria

• Infectious diseases
• Increased body temperature before any step of the study
• Individual hyperthermia (sauna) intolerance
• Any condition which in the opinion of the investigator would make it unsafe or unsuitable for the volunteer to participate in this study e.g. expected survival <1 year
• Participation in another clinical study with an investigational product within 28 days prior to enrolment or previous randomization to an investigational product in another ongoing clinical study