Effects of slow- v. fast-digested protein supplementation combined with mixed power training on muscle function and functional capacities in older men

Abstract

Aging leads to a progressive loss of muscle function (MF) and quality (MQ: muscle strength [MS]/lean muscle mass [LM]). Power training and protein (PROT) supplementation have been proposed as efficient interventions to improve MF and MQ. Discrepancies between results appear to be mainly related to the type and/or dose of proteins used. The present study aimed at determining whether or not mixed power training (MPT) combined with fast-digested PROT (F-PROT) leads to greater improvements in MF and MQ in elderly men than MPT combined with slow-digested PROT (S-PROT) or MPT alone. Sixty elderly men (Age:69±7years; BMI:18-30kg.m-2) randomized into 3 groups: 1) Placebo+MPT (PLA; n=19); 2) F-PROT+MPT (n=21); 3) S-PROT+MPT (n=20) completed the intervention. LM, handgrip and knee extensor MS and MQ, functional capacity, serum metabolic markers, skeletal muscle characteristics, dietary intake and total energy expenditure were measured. The interventions consisted in 12 weeks of MPT (3-times/week;1h/session) combined with a supplement (30g: 10g per meal) of F-PROT (whey) or S-PROT (casein) or a Placebo. No difference was observed among groups for age, BMI, number of steps and dietary intake pre- and post-intervention. All groups improved significantly their LM, and lower limb MS/MQ, functional capacity, muscle characteristics and serum parameters following the MPT. Importantly, no difference between groups was observed following the MPT. Altogether, adding 30 g PROT per day to MPT, regardless of the type, does not provide additional benefits to MPT alone in older men ingesting an adequate (i.e. above recommended daily allowance) amount of protein per day.

Systematic review and meta‐analysis of protein intake to support muscle mass and function in healthy adults

“…Sixty‐six out of 74 studies were included in the lean body mass change analysis, utilizing 2665 subjects 33–99 . Six studies presented intervention groups not using RE training 41,46,94,97–99 ; of these, four studies tested protein ingestion exclusively, 41,97–99 and two studies tested protein ingestion in groups without and with resistance exercise 46,94 .…”

“…Six studies presented intervention groups not using RE training 41,46,94,97–99 ; of these, four studies tested protein ingestion exclusively, 41,97–99 and two studies tested protein ingestion in groups without and with resistance exercise 46,94 . Changes in strength data resulting from the additional protein intervention were extracted from 50 studies testing 2283 subjects for lower‐body strength 33,36–39,43,44,47–49,52–58,61–65,67–70,72,74–78,82,84,86,88–92,94,96,100–104 and only three studies with intervention groups without RE 41,99,105 . Thirty‐four studies tested bench‐press strength 33,36–38,43,47–49,53–55,62–65,67,68,70,72,74,75,77,78,82,84,86–88,90,91,93,95,96,99 with 1049 subjects.…”

“…Sixty‐six out of 74 studies were included in the lean body mass change analysis, utilizing 2665 subjects. 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 ,…”

Does the Combination of Resistance Training and A Nutritional Intervention Have A Synergic Effect on Muscle Mass, Strength, and Physical Function in Older Adults? A Systematic Review and Meta-Analysis

“…It is recommended that older adults consume ≥ 0.4 g/kg per meal and 1.2-1.6 g/kg per day to induce muscle protein synthesis saturation to thus support muscle function [41]. Among the included studies, two studies provided an appropriate amount of protein (10 g milk protein and 0.5 g/kg whey protein) three times a day, taking into account frequency and distribution [21,25,26]. Other studies provided 10.1 g-25 g protein once a day [44][45][46][47] or 20 g ~ 35 g protein 3 times a week on the days exercise was performed [48][49][50].…”

“…Several evidencebased systematic reviews and meta-analyses of RCTs have shown that exercise affects muscle mass, strength, and physical performance [17,20]. For optimal effects, multimodal exercise combined with moderate-to high-intensity progressive resistance training and functional balance and mobility training at least twice a week for 30-45 minutes per session is recommended [19,21].…”