Introduction. The NAD+ (Nicotinamide Adenine Dinucleotide) dependent PARP1 (poly-ADP-ribose polymerase1) enzyme is confined to the nuclear and cytoplasmic compartments. Activation of PARP1 cleaves the cofactor NAD+, yielding salvageable nicotinamide and ADP-ribose that is post-translationally applied to target proteins altering their biological activity (known as PARylation). Well established within the DNA Damage Repair Response, PARP1 inhibition has clinical utility in the treatment of a variety of cancers and it has been assumed that in absence of DNA damage PARP1 was basally inactive. However, emergent data indicate PARP1 may target additional fundamental cellular pathways governing energy metabolism and cellular identity. In parallel, our knowledge surrounding the molecular drivers of skeletal muscle cell differentiation is currently incomplete. Declines in myogenic capacity, muscle fiber contractility and metabolic adaptation all currently underpin the loss of physiological performance recorded in aged humans. Aims. Here we asked whether modulation of the cells major NAD+ consumer PARP1 influences the progress of skeletal muscle differentiation or the metabolic capability of newly formed myotubes. Methods + Results. Analysis of C2C12 (murine myoblast) differentiation demonstrates basally detectable levels of both PARP-1 and PARylation (using Western immunoblotting (n=6)). Cellular levels of PARylation rise to a peak on day 1 of differentiation, coinciding with reduction in serum concentrations and PARylation trends downwards from days 2 through 6 with PARP1 also declining. PARP1 inhibitor treatment during differentiation significantly reduces levels of PARylation detectable by western blotting (n=6, 0.6 fold decrease ±0.08 SEM, p<0.005). Unbiased LC-MS evaluation (n=9) of these lysates showed PARP1 inhibition significantly altered the abundance of proteins regulating skeletal muscle development (5.85 Fold Enrichment, Pvalue 2.27×10-11), muscle contraction (15.4 Fold Enrichment, Pvalue 1.14×10-11) and myofibre assembly (18.35 Fold Enrichment, Pvalue 4.57×10-09). These data support the hypothesis that PARP1 controls the myogenic trajectory of skeletal muscle differentiation. RNAseq analysis (n=5) of SiRNA PARP1 in differentiating C2C12 muscle cells  significantly altered the expression of 275 genes (165 Upregulated and 110 Downregulated (p<0.005)). Pathway enrichment of these genes was found not only to dysregulate well established PARP1 regulators like Base excision repair and RNA transport, but also overrepresentation of novel PARP1 associated pathways governing muscle folate metabolism (Pvalue 9.77×10-06), protein folding events (Pvalue 7.76×10-06) and glycogen formation (Pvalue 3.16×10-03). Additionally, we show glucose deprivation of C2C12 myotubes elevates levels of PARylation in a concentration dependent manner emphasising the potential importance of PARP1 to muscle cell energy homeostasis (n=3, Pvalue 0.05). Conclusions. These data show that PARP1 mediated PARylation is dynamic during muscle differentiation and plays hitherto unanticipated roles in muscle physiology. Moreover, it suggests that cellular NAD+ availability may be of underappreciated importance to the inherent processes of differentiation, cellular architecture and energy metabolism.