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Endurance (ET), Resistance (RT), and Combined (CT) Training Increase Mixed Muscle Protein Synthesis Independently of Age
Author(s) -
Irving Brian A,
Lanza Ian R,
Henderson Gregory C,
Weymiller Audrey,
Sun Yiquan,
Nair K S
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.1149.1
Subject(s) - matrix metalloproteinase , medicine , endocrinology , endurance training
The effects of different modes of exercise on mixed muscle protein synthesis (MMPS) in young (Y) and older (O) adults are not fully understood. We determined the effects of ET, RT, and CT on MMPS in 33Y (25±1y) and 31O (70±1y) adults who were randomized to one of three 8wk interventions: (i) Control: no exercise, (ii) ET: cycling 1h @ 65% VO 2 peak, 5x/wk, (iii) RT: RT 4x/wk. After completing the control period, the controls completed an 8wk (iv) CT program (ET & RT). Subjects were studied at baseline and 48h following the last training bout. [ 13 C 6 ]Phe was infused for 8h, with serial v. lateralis biopsies. Isotopic enrichments (IE) were measured by LC/MS for free Phe from tissue fluid (TF) and from that incorporated into MMP. MMPS (%/h) = (ΔIE MMP )/(IE TF )/t*100. A rank sum test was used to test baseline differences between Y and O. 2‐way ANCOVA was used to test for differences between groups by treatment, with baseline values serving as the covariate. MMPS (%/h) tended to be higher in Y (0.060±0.003) compared to O (0.053±0.003) (P=0.06). ET [57%, P<0.0001], RT [21%, P=0.042] and CT [42%, P<0.0001] increased MMPS independently of age (P>0.4). The ET‐induced increase in MMPS was greater than the RT‐induced increase (P<0.05), although ET unlike RT does not increase muscle mass suggesting that muscle protein turnover was increased. In conclusion, ET, RT and CT were effective at increasing MMPS independently of age. R01AG09531, KL2RR024151