The effects of a high-protein diet on markers of muscle damage following exercise in active older adults: A randomized, controlled trial

Tom Clifford*, Eleanor J. Hayes, Jadine H. Scragg, Guy Taylor, Kieran Smith, Kelly A. Bowden Davies, Emma J. Stevenson

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)

Abstract

Purpose: This study examined whether a higher protein diet following strenuous exercise can alter markers of muscle damage and inflammation in older adults.
Methods: Using a double-blind, independent group design, 10 males and eight females (age 57 ± 4 years; mass 72.3 ± 5.6 kg; height 1.7 ± 6.5 m) were supplied with a higher protein (2.50 g·kg−1·day−1) or moderate protein (1.25 g·kg−1·day−1) diet for 48 hr after 140 squats with 25% of their body mass. Maximal isometric voluntary contractions, muscle soreness, creatine kinase, Brief Assessment of Mood Adapted, and inflammatory markers were measured preexercise, and 24 hr and 48 hr postexercise.
Results: The maximal isometric voluntary contractions decreased postexercise (p = .001, η2p = .421), but did not differ between groups (p = .822, η2p = .012). Muscle soreness peaked at 24 hr post in moderate protein (44 ± 30 mm) and 48 hr post in higher protein (70 ± 46 mm; p = .005; η2p = .282); however, no group differences were found (p = .585; η2p = .083). Monocytes and lymphocytes significantly decreased postexercise, and eosinophils increased 24 hr postexercise (p < 0.05), but neutrophils, creatine kinase, interleukin-6, C-reactive protein, monocyte chemotactic protein-1, and Brief Assessment of Mood Adapted were unchanged by exercise or the intervention (p > .05).
Conclusion: In conclusion, 2.50 g·kg−1·day−1 of protein is not more effective than 1.25 g·kg−1·day−1 for attenuating indirect markers of muscle damage and inflammation following strenuous exercise in older adults.
Original languageEnglish
Pages (from-to)323-329
Number of pages7
JournalInternational Journal of Sport Nutrition and Exercise Metabolism
Volume30
Issue number5
Early online date21 Jul 2020
DOIs
Publication statusPublished - 1 Sept 2020
Externally publishedYes

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