INTRODUCTION: Age-related loss of muscle mass and strength, sarcopaenia, burdens many older adults. The process is accelerated with bed rest, protein intakes below requirements and the catabolic effect of certain illnesses. Thus, acutely ill, hospitalised older adults are particularly vulnerable. Protein supplementation can preserve muscle mass and/or strength and, combining this with resistance exercise training (RT), may have additional benefits. Therefore, this study investigates the effect of protein supplementation as an addition to offering RT among older adults while admitted to the geriatric ward and after discharge. This has not previously been investigated.

METHODS AND ANALYSIS: In a block-randomised, double-blind, multicentre intervention study, 165 older adults above 70 years, fulfilling the eligibility criteria, will be included consecutively from three medical departments (blocks of n=20, stratified by recruitment site). After inclusion, participants will be randomly allocated (1:1) to receive either ready-to-drink, protein-enriched, milk-based supplements (a total of 27.5 g whey protein/day) or isoenergetic placebo products (<1.5 g protein/day), twice daily as a supplement to their habitual diet. Both groups will be offered a standardised RT programme for lower extremity muscle strength (daily while hospitalised and 4×/week after discharge). The study period starts during their hospital stay and continues 12 weeks after discharge. The primary endpoint is lower extremity muscle strength and function (30 s chair-stand-test). Secondary endpoints include muscle mass, measures of physical function and measures related to cost-effectiveness.

ETHICS AND DISSEMINATION: Approval is given by the Research Ethic Committee of the Capital Region of Denmark (reference no. H-16018240) and the Danish Data Protection Agency (reference no. HGH-2016-050). There are no expected risks associated with participation, and each participant is expected to benefit from the RT. Results will be published in peer-reviewed international journals and presented at national and international congresses and symposiums.

TRIAL REGISTRATION NUMBER: NCT02717819 (9 March 2016).