Table 4.

Summary of selected studies examining the long-term (>2 weeks) effects on strength performance.

Author and Year	Subjects	Duration	Dosing Protocol	Primary Variables	Results	Adverse Events
Peak Torque/Force Production
Stevenson et al. 2001	18 (17 males, 1 female) trained subjects	9 weeks	20 g/day for 7 days 5 g/day 8 weeks	maximal torque on isokinetic dynamometer quadriceps cross-sectional area	↔ maximal torque ↑ cross-sectional area	None reported
Chrusch et al. 2001	30 healthy older males	12 weeks	0.03 g/kg/day for 5 days 0.07 g/kg/day for 11 weeks	lean tissue bench press strength leg press strength knee extension muscle endurance average power	↑ lean tissue ↔ bench press ↑ leg press ↑ knee torque ↑ muscle endurance ↑ average power	None reported
Strength
Vandenberghe et al.1997	19 healthy female subjects	11 weeks	5 g/day for 4 days 2.5 g/day for 10 weeks	arm flexion on isokinetic dynamometer upper and lower body muscle strength body composition	↑ arm torque ↑ leg press, leg extension, squat ↔ bench press, leg curl, shoulder press ↑ lean muscle mass	None reported
Kelly et al. 1998	18 male powerlifters	26 days	20 g/day for 5 days 5 g/day for 21 days	bench press strength bench press endurance total body mass	↑ bench press strength ↑ bench press endurance ↑ body mass	None reported
Volek et al. 1999	19 trained males	12 weeks	25 g/day for 7 days 5 g/day for 11 weeks	body mass fat-free mass bench press strength squat strength quadriceps cross-sectional area	↔ body mass ↑ fat-free mass ↑ bench press ↑ squat ↑ quadriceps cross-sectional area	None reported
Becque et al. 2000	23 trained males	6 weeks	20 g/day for 5 days 2 g/day for days 6–42	upper body strength body composition	↑ arm flexor strength ↑ body mass ↔ body fat ↑ fat-free mass ↑ upper arm muscle area	None reported
Brenner et al. 2000	20 female college lacrosse players	5 weeks	20 g/day for 7 days 2 g/day for days 8–32	body composition bench press strength knee extension strength knee extension endurance BLa	↔ body composition ↑ bench press strength ↔ knee extension strength ↔ knee extension endurance ↔ BLa	None reported
Larson-Meyer et al. 2000	14 female college soccer players	13 weeks	15 g/day for 5 days 5 g/day 5 days/week for 12 weeks	bench press strength squat strength vertical jump body composition	↑ bench press strength ↑ squat strength ↔ vertical jump ↑ body mass ↑ lean mass ↔ body fat	1 subject reported nausea
Bemben et al. 2001	25 male college football players	9 weeks	20 g/day for 5 days 5 g/day for 8 weeks	bench press strength squat strength power clean strength Wingate cycling test isokinetic strength body composition	↑ bench press strength ↑ squat strength ↑ power clean strength ↑ anaerobic power, capacity and % decrement ↑ peak torque knee flexion ↔ peak torque knee extension ↑ lean body mass ↔ body fat	None reported
Burke et al. 2001	47 active male subjects	21 days	7.7 g/day for 21 days	bench press on a isokinetic dynamometer	↑ peak force ↑ peak power ↑ time to fatigue	None reported
Chrusch et al. 2001	30 healthy older males	12 weeks	0.03 g/kg/day for 5 days 0.07 g/kg/day for 11 weeks	lean tissue bench press strength leg press strength knee extension muscle endurance average power	↑ lean tissue ↔ bench press ↑ leg press ↑ knee torque ↑ muscle endurance ↑ average power	None reported
Wilder et al. 2001	25 male college football players	10 weeks	3 g/day for 10 week or 20 g/day for 7 days, then 5 g/day for rest of the study	squat strength body composition	↔ squat strength ↔ lean body mass ↔ fat mass	None reported
Burke et al. 2003	49 (20 male, 29 female) active subjects	8 weeks	0.25 g/kg lean tissue/day for 7 days 0.0625 g/kg lean tissue/day for 49 days	bench press strength leg press strength isokinetic endurance quadriceps cross-sectional area body composition	↑ bench press ↔ leg press ↑ total work ↑ body mass ↑ lean body mass ↑ cross-sectional area	None reported
Ferguson et al. 2006	26 trained females	10 weeks	0.3 g/kg for 7 days 0.03 g/kg for 9 weeks	bench press strength leg press strength body composition	↔ bench press ↔ leg press ↔ total mass ↔ lean body mass ↔ fat mass	None reported
Kerksick et al. 2009	24 trained males	4 weeks	20 g/day for 5 days 5 g/day for 23 days	bench press strength leg press strength isokinetic knee extension Wingate cycling test body composition	↑ bench press ↑ leg press ↔ peak torque ↔ peak power ↑ lean body mass ↑ fat-free mass	None reported
Camic et al. 2010	22 untrained males	28 days	5 g/day for 28 days	bench press strength leg extension strength Wingate cycling test	↑ bench press ↔ leg extension ↔ mean power ↔ peak power	None reported
Hummer et al. 2019	22 (16 males, 6 females) active subjects	6 weeks	4 g/day for 6 weeks	bench press strength bench press endurance squat strength squat endurance	↑ bench press strength ↑ bench press endurance ↑ squat strength ↔ squat endurance	None reported
Strength and Performance Outcomes
Kreider et al. 1998	25 college football players	28 days	15.75 g/day for 28 days	total work during sprints on a cycle ergometer bench press volume total volume	↑ total work ↑ bench press volume ↑ total volume	None reported
Stone et al. 1999	42 college football players	5 weeks	0.22 g/kg/day for 5 weeks	bench press strength squat strength countermovement vertical jump static vertical jump body composition	↑ bench press strength ↔ squat strength ↔ countermovement vertical jump ↔ static vertical jump ↑ body mass ↑ lean body mass	None reported
Chilibeck, et al. 2007	19 male union rugby players	8 weeks	0.7 g/kg/day for 8 weeks	bench press endurance leg press endurance body composition	↔ bench press repetitions ↔ leg press repetitions ↑ when combining bench press and leg press scores ↔ total body mass ↔ lean tissue mass ↔ fat mass	None reported

BLa = blood lactate; CR or no identifier = creatine monohydrate; ↓ indicates decrease; ↑ indicates increase; ↔ indicates no difference.