Free leucine supplementation during an 8-week resistance training program does not increase muscle mass and strength in untrained young adult subjects

Amino Acids ◽  
2017 ◽  
Vol 49 (7) ◽  
pp. 1255-1262 ◽  
Author(s):  
Andreo Fernando Aguiar ◽  
Alan Pablo Grala ◽  
Rubens Alexandre da Silva ◽  
Lúcio Flávio Soares-Caldeira ◽  
Francis Lopes Pacagnelli ◽  
...  
2019 ◽  
Vol 37 (15_suppl) ◽  
pp. 10027-10027
Author(s):  
Matthew R Krull ◽  
Carrie R. Howell ◽  
Robyn Partin, MS ◽  
Ginger Carney ◽  
Daniel A. Mulrooney ◽  
...  

10027 Background: Muscle weakness, low lean muscle mass and poor physical performance are prevalent among adult survivors of childhood cancer. We evaluated the effects of resistance training with and without protein supplementation on lean muscle mass, and muscle strength among childhood cancer survivors. Methods: This double-blind placebo-controlled trial enrolled survivors aged ≥18 to < 45 years. Participants were randomized to resistance training with daily protein supplement (21g protein/day, 90kcal) (RT+S) or resistance training with placebo (sucrose, 90kcal) (RT+P). Both groups received educational materials, access to a local fitness center and a tailored resistance training program with tapered supervision. Lean muscle mass and muscle strength were assessed at baseline and 24 weeks, using dual x-ray absorptiometry and dynamometer testing respectively. Mean changes were compared within and between groups. Results: Of 93 participants randomized, 57 completed the 24-week intervention (24 in RT+S, 33 in RT+P). The mean age was 33.1 (SD 7.0), 67% were white and 47% female. The RT+S group had a significant increase in lean body mass (1.05 kg [SD 2.34], p = 0.04), while the RT+P group did not (0.13 kg [SD 2.19], p = 0.74). Mean change in handgrip strength also improved in the RT+S group (1.98 [SD 4.30], p = 0.03); change approached significance in the RT+P group (1.49 [SD 4.60], p = 0.07). All survivors significantly improved their strength over time (Table) as measured by one max repetition test at baseline and follow-up. Conclusions: Preliminary findings indicate that a supervised resistance training program among adult survivors of childhood cancer that includes protein supplementation is feasible and may increase total lean body mass and muscle strength. Clinical trial information: NCT02501460. [Table: see text]


2011 ◽  
Vol 6 (1) ◽  
pp. 38-50 ◽  
Author(s):  
Theocharis Ispoglou ◽  
Roderick F.G.J. King ◽  
Remco C.J. Polman ◽  
Cathy Zanker

Purpose:To investigate the effects of daily oral L-leucine ingestion on strength, bone mineral-free lean tissue mass (LTM) and fat mass (FM) of free living humans during a 12-wk resistance-training program.Methods:Twenty-six initially untrained men (n = 13 per group) ingested either 4 g/d of L-leucine (leucine group: age 28.5 ± 8.2 y, body mass index 24.9 ± 4.2 kg/m2) or a corresponding amount of lactose (placebo group: age 28.2 ± 7.3 y, body mass index 24.9 ± 4.2 kg/m2). All participants trained under supervision twice per week following a prescribed resistance training program using eight standard exercise machines. Testing took place at baseline and at the end of the supplementation period. Strength on each exercise was assessed by fve repetition maximum (5-RM), and body composition was assessed by dual energy X-ray absorptiometry (DXA).Results:The leucine group demonstrated significantly higher gains in total 5-RM strength (sum of 5-RM in eight exercises) and 5-RM strength in five out of the eight exercises (P < .05). The percentage total 5-RM strength gains were 40.8% (± 7.8) and 31.0% (± 4.6) for the leucine and placebo groups respectively. Significant differences did not exist between groups in either total percentage LTM gains or total percentage FM losses (LTM: 2.9% ± 2.5 vs 2.0% ± 2.1, FM: 1.6% ± 15.6 vs 1.1% ± 7.6).Conclusion:These results suggest that 4 g/d of L-leucine supplementation may be used as a nutritional supplement to enhance strength performance during a 12-week resistance training program of initially untrained male participants.


Author(s):  
Ana Victoria Costa Freitas ◽  
Inês Amanda Streit ◽  
Josefina Bertoli ◽  
Kayth Andrade Nascimento ◽  
Maria Carolina Oliveira de Sá ◽  
...  

2017 ◽  
Vol 36 (12) ◽  
pp. 1331-1339 ◽  
Author(s):  
Alejandro Pérez-Castilla ◽  
Amador García-Ramos ◽  
Paulino Padial ◽  
Antonio J. Morales-Artacho ◽  
Belén Feriche

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