(C)

Author/s—Year	Study Design	Population	Intervention	Analyzed Results	Main Conclusions
Zamora et al., 1995 [29]	Placebo-controlled, double-blind, randomized	24 ♂ healthy students; 22.9 ± 2.1 y; 68.0 ± 8.7 Kg; 178.1 ± 6.6 cm; Body fat 11.2 ± 4.4 % PbG n = 12 ♂ 22.5 ± 2.0 y; 67.3 ± 7.0 Kg; 177.4 ± 7.0 cm; Body fat 10.1 ± 3.9 % SeG n = 12 ♂ 23.28 ± 2.36 y; 68.78 ± 10.44 Kg; 178.7 ± 6.3 cm; Body fat 12.3 ± 4.8 %	Supplementation: 180 μg Se (Seleniomethionine) once per day * 10-week period PhA: 10-week endurance training programme (3 sessions per week) after a 4-week period of restricted		At rest		Post-PhA
					Pre-PhA vs. Post-PhA	SeG vs. PbG	Pre-PhA vs. Post-PhA	SeG vs. PbG
				Muscle mitochondria morphometric parameters QA Aa â	↑*SelG ↔ PbG ↑*SelGr ↔ PbG ↔ SelGr ↔ PbG	#SelGr vs PbG #SelGr vs PbG #SelGr vs PbG	↑*SelG ↔ PbG ↑*SelG ↔ PbG ↔ SelGr ↔ PbG	#SelGr vs PbG ↔ SelGr vs PbG #SelGr vs PbG
				VO2max	↔ SelGr ↔ PbG	† SelGr vs PbG	↔ SelGr ↔ PbG	† SelGr vs PbG
				Body fat %	↔ SelGr ↔ PbG	† SelGr vs PbG	↔ SelGr ↔ PbG	† SelGr vs PbG
				BMI Kg*m2	↔ SelGr ↔ PbG	† SelGr vs PbG	↔ SelGr ↔ PbG	† SelGr vs PbG
Tessier et al., 1995 [30]	Placebo-controlled, double-blind, randomized	24 ♂ healthy; 22.9 ± 2.1 y	Supplementation: 240 μg organic selenium (70% selenomethionine) Selenion® once per day *10-week period PhA: 4-week deconditioning period with no training, followed by running endurance training lasting 10 week (3 sessions/week).		Pre-PhA vs. Post-PhA		SeG vs. PbG
				[Se]	↑*SelG ↓PbG		† SelGr vs PbG
				Vitamin E	↓SelG ↑PbG		† SelGr vs PbG
				GPx muscle
				PhA cronic	↓SelG ↓PbG		† SelGr vs PbG
				PhA acute	↑*SelG ↓*PbG		# SelGr vs PbG

♂: Men; ♀: Women; NW: Normal weight; OW: Over weight; y: Years; Kg: Kilograms; m: Meters; cm: Centimeters; BMI: Body mass index; PhA: Physical activity; Se: Selenium; [Se]: Plasma Selenium levels; ↑*: Statistically significant increase; ↑: Non-statistical increase; ↓*: Statistically significant decrease; ↓: Non-statistical decrease; †: Change without statistical significance; #: Change statistical significance; ↔: Without changes; LH: Lipid hydroperoxidase; GSH: Reduced glutathione; SOD: Superoxide dismutase; TAS: Total antioxidant status; PbG: Placebo group; SeG: Selenium group; GT_total: Glutathione total; GSSG: Glutathione oxidized; GPx: Glutathione peroxidase; EGPx: Erythrocyte glutathione peroxidase; EGR: Erythrocyte glutathione reductase; VO₂max: Maximum oxygen consumption; Tt: Total testosterone; Tf: Testosterone free; [La]: Plasma lactate; CK: Creatine kinase; Cyt Ox: Cytochrome C oxidase; SDH: Succinate dehydrogenase; MCH: Myosin heavy chains; Q_A: Density of the mitochondria profile; A_a: surface of all the mitochondria profile area; â: mean surface of individual mitochondria profile area.