Table 2.

Main characteristics of the studies included in the systematic review.

Author, year, country	Sample characteristics	Study design	Intervention characteristics	Follow-up	Exercise test	Main results (curcumin vs. control groups)
						Primary outcome	Secondary outcome
Tanabe et al. (2015) Japan	n: 14 young individuals Gender: M: 14 Age: 23.5 ± 2.3 years old Weight: 65.2 ± 11.3 kg	Single-blind crossover randomized controlled trial	G1: 300 mg/day of curcumin (Theracurmin-Theravalues®) G2: 300 mg/day of placebo (starch)	1 day Capsules administered 1 h before (150 mg) and 12 h after exercise (150 mg)	50 maximal eccentric contractions of the elbow flexors separated by 4 weeks	↔ IL-6, TNF-α ↓ CK ↔ muscle pain ↔ ROM ↑ MVC torque	↔ Total work, mean peak torque, upper-arm circumference
McFarlin et al. (2016) USA	n: 28 young individuals Gender: M: 10 W: 18 Age: G1: 20 ± 1 years old G2: 19 years old Weight: G1: 62.4 ± 11.4 G2: 65.0 ± 10.3	Double-blind randomized controlled trial	G1: 400 mg/day of curcumin (long-life) G2: 400 mg/day of placebo (rice flour)	6 days 48 h before exercise and for 72 h after	6 series of 10 repetitions of eccentric exercise (leg press) with initial load set at 110% of the estimated 1RM	↓ IL-8 and TNF-α ↔ IL-6 and IL-10 ↓ CK ↔ muscle pain	↔ ADL
Tanabe et al. (2019a) Japan	n: 24 healthy adults Gender: M: 24 Age: PRE: 28.8 ± 3.6 years old POST: 29.8 ± 3.4 years old CON: 28 ± 3.2 years old Weight: PRE: 65.2 ± 11 kg POST: 71.2 ± 5.6 kg CON: 65.7 ± 5.9 kg	Single-blind parallel randomized trial	PRE: 180 mg/day of curcumin capsules (Theracurmin-Theravalues®) POST: 180 mg/day of curcumin (Theracurcumin-Theravalues®) CON: 180 mg/day of placebo	PRE: 7 days before exercise POST: 4 days after exercise CON: 4 days after exercise	30 eccentric contractions of the elbow flexors	↔ CK (PRE and POST) ↓ muscle pain on POST ↑ ROM on POST ↔ MVC torque, ROM initially	↔ total work during exercise
Tanabe et al. (2019b) Japan	n: 20 healthy adults Gender: M: 20 Age: Exp 1: 28.5 ± 3.4 years old Exp 2: 29 ± 3.9 years old Weight: Exp 1: 64.9 ± 10.1 kg Exp 2: 70.7 ± 5.8 kg	Double-blind crossover, randomized controlled trial	Exp 1: G1: 180 mg/day of curcumin capsules (Theracurmin-Theravalues®) G2: placebo (starch) Exp 2: G1: 180 mg/day of curcumin capsules (Theracurmin-Theravalues®) G2: placebo (starch)	Exp 1: 7 days before exercise Exp 2: 7 days after exercise	30 eccentric contractions of the elbow flexors	Exp 1: ↓ IL-8 ↔ TNF-α ↔ CK, muscle pain ↔ MVC, ROM Exp 2: ↔ IL-8, TNF-α ↓ CK, muscle pain ↑ MVC torque, ROM	Exp 1: ↔ total work during exercise, d-ROMs, T2, BAP Exp 2: ↔ total work during exercise, d-ROMs, T2, BAP
Wang et al. (2019) China	n: 12 healthy young individuals Gender: W: 12 Age: 21.2 ± 1.1 years old Weight: G1: 57.1 ± 5.1 kg G2: 56.5 ± 7.6 kg	Double-blind, parallel, randomized, controlled trial	G1: 230.9 mg/day of NCE G2: 15 g/day placebo (maltodextrin)	4 weeks	A single test of 3 repetitions of drop jumps high (DJH) 70%, 100% (defined as the highest jump height), and 130% Acute bicycle challenge for 15 minutes	↔ CK ↓ lactate, NH3, knee injury index ↑ contact time drop jumps (muscle strength)	↓ ALT, ALP, TG ↑ HDL-c ↔ AST, LDH, albumin, glucose

↑: statistically significant increase; ↔: change without statistical significance; ↓: statistically significant decrease; M: men; W: women; CK: creatine kinase; IL-6: interleukin-6; IL-8: interleukin-8; IL-10: interleukin-10; TNF-α: tumor necrosis factor-alpha; MVC torque: maximum voluntary contraction torque; ROM: range of motion; ALT: alanine aminotransferase; ALP: alkaline phosphatase; AST: aspartate aminotransferase; TG: triglycerides; HDL-c: high-density lipoprotein; LDH: lactate dehydrogenase; ADL: activities of daily living; T2: transverse relaxation time; d-ROMs: derivatives of reactive oxygen metabolites; BAP: biological antioxidant potential; Exp: experiment; PRE: PRE group; POST: POST group; CON: control group; NCE: nanobubble water curcumin extract; RM: repetition maximum.