The Effects of Beef, Chicken, or Whey Protein After Workout on Body Composition and Muscle Performance.

Sharp, MH, Lowery, RP, Shields, KA, Lane, JR, Gray, JL, Partl, JM, Hayes, DW, Wilson, GJ, Hollmer, CA, Minivich, JR, and Wilson, JM. The effects of beef, chicken, or whey protein after workout on body composition and muscle performance. J Strength Cond Res 32(8): 2233-2242, 2018-The purpose of this study was to determine the effects of postworkout consumption of beef protein isolate (Beef), hydrolyzed chicken protein (Chx), or whey protein concentrate (WPC), compared with a control on body composition and muscle performance during 8 weeks of resistance training. Forty-one men and women were randomized into 4 groups: WPC (m = 5, f = 5; age [years] = 19 ± 2, height [cm] = 171 ± 10, mass [kg] = 74.60 ± 14.19), Beef (m = 5, f = 5; age [years] = 22 ± 4, height [cm] = 170 ± 7, mass [kg] = 70.13 ± 8.16), Chx (m = 5, f = 6; Age [years] = 21 ± 2, height [cm] = 169 ± 9, mass [kg] = 74.52 ± 13.83), and Maltodextrin (control) (m = 4, f = 6; age [years] = 21 ± 2, height [cm] = 170 ± 9, mass [kg] = 73.18 ± 10.96). Subjects partook in an 8-week periodized resistance training program. Forty-six grams of protein or a control were consumed immediately after training or at similar times on off-days. Dual-energy x-ray absorptiometry was used to determine changes in body composition. Maximum strength was assessed by 1 repetition maximum for bench press (upper body) and deadlift (lower body). Power output was measured using cycle ergometer. Whey protein concentrate (52.48 ± 11.15 to 54.96 ± 11.85 kg), Beef (51.68 ± 7.61 to 54.65 ± 8.67 kg), and Chx (52.97 ± 12.12 to 54.89 ± 13.43 kg) each led to a significant increase in lean body mass compared with baseline (p < 0.0001), whereas the control condition did not (53.14 ± 11.35 to 54.19 ± 10.74 kg). Fat loss was also significantly decreased at 8 weeks compared to baseline for all protein sources (p < 0.0001; WPC: 18.70 ± 7.38 to 17.16 ± 7.18 kg; Beef: 16.43 ± 5.71 to 14.65 ± 5.41 kg; Chx: 17.58 ± 5.57 to 15.87 ± 6.07 kg), but not the control condition (16.29 ± 7.14 to 14.95 ± 7.72 kg). One repetition maximum for both deadlift and bench press was significantly increased for all treatment groups when compared with baseline. No differences in strength were noted between conditions. Overall, the results of this study demonstrate that consuming quality sources of protein from meat or WPC lead to significant benefits in body composition compared with control.

Oral Adenosine-5'-triphosphate (ATP) Administration Increases Postexercise ATP Levels, Muscle Excitability, and Athletic Performance Following a Repeated Sprint Bout.

OBJECTIVE: Oral adenosine-5'-triphosphate (ATP) administration has failed to increase plasma ATP levels; however, chronic supplementation with ATP has shown to increase power, strength, lean body mass, and blood flow in trained athletes. The purpose of this study was to investigate the effects of ATP supplementation on postexercise ATP levels and on muscle activation and excitability and power following a repeated sprint bout. METHODS: In a double-blind, placebo-controlled, randomized design, 42 healthy male individuals were given either 400 mg of ATP as disodium salt or placebo for 2 weeks prior to an exercise bout. During the exercise bout, muscle activation and excitability (ME, ratio of power output to muscle activation) and Wingate test peak power were measured during all sprints. ATP and metabolites were measured at baseline, after supplementation, and immediately following exercise. RESULTS: Oral ATP supplementation prevented a drop in ATP, adenosine-5'-diphosphate (ADP), and adenosine-5'-monophosphate (AMP) levels postexercise (p < 0.05). No group by time interaction was observed for muscle activation. Following the supplementation period, muscle excitability significantly decreased in later bouts 8, 9, and 10 in the placebo group (-30.5, -28.3, and -27.9%, respectively; p < 0.02), whereas ATP supplementation prevented the decline in later bouts. ATP significantly increased Wingate peak power in later bouts compared to baseline (bout 8: +18.3%, bout 10: +16.3%). CONCLUSIONS: Oral ATP administration prevents exercise-induced declines in ATP and its metabolite and enhances peak power and muscular excitability, which may be beneficial for sports requiring repeated high-intensity sprinting bouts.