**6. Conclusions**

The gradual loss of skeletal muscle mass in CHD patients accelerates after initiation of intermittent HD treatment. Muscle protein breakdown rates in CHD patients are increased, while muscle protein synthesis rates fail to match this increase due to insufficient protein ingestion, amino acid extraction during HD, and the prevalence of anabolic resistance. Protein intake of CHD patients should be increased

on dialysis days to compensate for extraction of circulating amino acids during HD and to compensate for the blunted muscle protein synthetic response to feeding in these patients. Implementing structured physical activity in the daily routine of CHD patients represents a feasible strategy to increase the skeletal muscle protein synthetic response to protein ingestion and, as such, to alleviate anabolic resistance. More insight in the impact of protein ingestion and exercise in CHD patients on both dialysis as well as non-dialysis days is required to develop more effective nutritional and exercise intervention programs that can attenuate or even prevent muscle loss in CHD patients.

**Author Contributions:** Writing—original draft preparation, F.K.H. and L.J.C.v.L.; writing—review and editing, J.S.J.S., F.M.v.d.S., and J.P.K., All authors read and approved the final manuscript.

**Funding:** This work was supported by a gran<sup>t</sup> from the NUTRIM NWO Graduate Programme.

**Conflicts of Interest:** The authors declare no conflicts of interest. The funders had no role in the writing of the manuscript or in the decision to publish.
