Effect of Inhaled Molecular Hydrogen on Recovery Process After Downhill Walking on the Treadmill

The main aim of this randomized, double-blind, placebo-controlled crossover study is to assess the effect of molecular hydrogen inhalation on recovery after downhill walking with an additional load of 15% of body mass on the treadmill with a negative slope of -15% at a speed of 6.5 km/h for 90 min. The study includes 12 participants, healthy males aged 20-35 years. The study consists of two experimental sessions, one using molecular hydrogen inhalation and the other using placebo inhalation. Randomization is performed using a computer random generator. Molecular hydrogen is colourless, odourless, and tasteless, so it cannot be distinguished from placebo by the human senses. The washout period between sessions is set at four weeks. One week before each session, participants are asked to follow diet and physical activity rules. Variables measured during the 48 h recovery are as follow: creatine kinase level, perceived muscle soreness, reactive strength index, malondialdehydes level, and interleukin-6 level. The following variables are also measured during exercise: heart rate, ventilation and gas exchange, and blood lactate level. Analysis of variance for repeated measures and Fisher's post hoc tests are used for statistical analysis. The significance level is set at 0.05.