Antioxidants in the diet protect against natural and synthetic chemical fragments called free radicals that are a part of daily living. Lifestyle challenges may increase your requirements for antioxidants. Vitamin C and E are the main antioxidants in the normal diet although many other plant nutrients contribute to this effect. Pollution, stress, smoking, strenuous exercise, and illness may increase your requirements for antioxidant protection.
In a pilot study on youth with cystic fibrosis, supplementation of creatine at 12g for a week and 6g for eleven weeks afterward was associated with a time-dependent increase in maximal isometric strength reaching 14.3%, which was maintained after 12-24 weeks of supplement cessation (18.2% higher than baseline).[485] This study noted that more patients reported an increase in wellbeing (9 subjects, 50%) rather than a decrease (3, 17%) or nothing (6, 33%) and that there was no influence on chest or lung symptoms.[485] 

Despite creatine not interfering with UV(A) irradiation acting upon a cell or the production of oxidation due to it, creatine appears to prevent the functional consequences (such as mitochondrial DNA damage) due to preventing an ATP depletion in the cell, which would normally precede a reduction in mitochondrial membrane potential and mutagenesis, but this effect is prevented for as long as creatine stores are sufficient.[446] Creatine has also been noted to near-fully protect mitochondrial DNA from hydroxyl radicals and oxidative damage, although there was no protective effect for nuclear DNA, due to it being less sensitive to hydroxyl radicals.[447]

Whether you’re taking a supplement or not, creatine is already functioning inside you, doing its very important job. It’s an amino acid found naturally in the meat and fish you consume and, according to the Mayo Clinic, your liver and kidneys crank it out as well. The creatine is mainly stored as creatine phosphate in your muscles, ready for use in energy production.

Contrary to the sound of the name, glucosamine is not a glucose replacement drink but a naturally occurring compound that has received publicity and wide support as a supplement for the relief of arthritis pain and possible prevention of further joint damage. Glucosamine has been popular with sports people of all types, including weight trainers, particularly for knee arthritis and pain. Glucosamine seems to be safe to use.

Creatine is a hydrophilic polar molecule that consists of a negatively charged carboxyl group and a positively charged functional group [64]. The hydrophilic nature of creatine limits its bioavailability [65]. In an attempt to increase creatines bioavailability creatine has been esterified to reduce the hydrophilicity; this product is known as creatine ethyl ester. Manufacturers of creatine ethyl ester promote their product as being able to by-pass the creatine transporter due to improved sarcolemmal permeability toward creatine [65]. Spillane et al [65] analyzed the effects of a 5 days loading protocol (0.30 g/kg lean mass) followed by a 42 days maintenance phase (0.075 g/kg lean mass) of CM or ethyl ester both combined with a resistance training program in 30 novice males with no previous resistance training experience. The results of this study [65] showed that ethyl ester was not as effective as CM to enhance serum and muscle creatine stores. Furthermore creatine ethyl ester offered no additional benefit for improving body composition, muscle mass, strength, and power. This research did not support the claims of the creatine ethyl ester manufacturers.