REF-345 · Areta et al., 2014 · American Journal of Physiology — Endocrinology and Metabolism · Paper · PubMed
Reduced resting skeletal muscle protein synthesis is rescued by resistance exercise and protein ingestion following short-term energy deficit
Participants
n=15 young adults (8 men, 7 women).
Protocol
Resting postabsorptive myofibrillar protein synthesis (MPS) and protein signalling measured in energy balance (45 kcal/kg fat-free mass/day) and after 5 days of energy deficit (30 kcal/kg FFM/day).
In energy deficit, MPS measured after an acute bout of resistance exercise in the fasted state and with 15 g or 30 g of whey protein.
Key Findings
Resting MPS was 27% lower in energy deficit than in energy balance (P<0.001).
A bout of resistance exercise in energy deficit restored MPS to the resting energy-balance rate.
Protein after exercise raised MPS further, dose-dependently: ~16% (15 g) and ~34% (30 g) above resting energy balance (P<0.02).
p70 S6K Thr389 phosphorylation rose above energy balance only with exercise plus protein (~2-7-fold).
Practical Application
In 15 young adults, five days at 30 kcal/kg FFM/day cut resting muscle protein synthesis by 27%, but a resistance-exercise bout brought it back to the energy-balance rate and 15-30 g of whey after exercise pushed it ~16-34% higher — during a short deficit, keep resistance training and eat protein after it; the deficit lowers resting synthesis, it does not blunt the response to exercise.
The authors' conclusion: combining resistance exercise with protein after exercise could, in the long term, preserve muscle mass during short-term energy deficit. Long-term muscle mass was not measured.
Limitations
One short (5-day) deficit and acute measurements; no training block, no muscle-mass or performance outcome.
Small sample; men and women pooled in the abstract.
The energy-balance and deficit conditions were measured in sequence, not in randomised order.
How this entry was checked and changed
Why this level
regraded 2026-09-27 from A: single within-subject study, n=15
Content correction 2026-09-27
The entry had no verified source: its first DOI resolved to a paper on oral contraceptives and its second (Melin 2019) to a paper on lotus seedpods. It is now the Areta 2014 study, verified DOI → work and approved by Misha.
"Short-term LEA blunts the post-exercise MPS response" -> the opposite: resistance exercise restored MPS to the energy-balance rate and protein raised it further. "~20-30%" -> 27% lower at rest.
Removed, because no source in the entry supports them: chronic-LEA effects on strength, lean mass, mitochondrial biogenesis and glycogen; "EA ≥ 40-45 during peak"; "limit the deficit to 250-300 kcal/day"; "body-composition and peak-performance goals are not simultaneously achievable".
Level A -> B; Tier composite N/A -> N/A (training status not given); byline -> Areta et al., 2014.