The participants (sedentary men and women ages 50 and over, without known health conditions) drank 1 liter of either hydrogen-rich water (providing 24 milligrams of molecular hydrogen) or a control water daily. All of the participants underwent a supervised resistance training program that involved 2 to 3 weekly sessions of 8 to 10 exercises.

Although hydrogen-rich water had no effect on health-related quality of life, it increased cortisol levels and prevented a postexercise increase in creatine kinase and myoglobin (both of which are biomarkers of muscle damage). There were no effects on strength, blood lipids, or sleep quality.

One of the researchers was employed by Natural Wellness Now Health Products, Inc. (the manufacturer of the hydrogen-rich water product).

Does hydrogen-rich water improve health-related quality of life in older adults? Original paper