Erythropoietin (EPO) is the master regulator of erythropoiesis and also plays a role in cytoprotection, cell proliferation and heart contractility. In human skeletal muscle, EPO mRNA expression increases in response to acute exercise, however, whether glycolytic or oxidative muscle fibers differentially produce EPO is unknown. Thus, the purpose of this study was to examine EPO mRNA expression in oxidative and glycolytic muscles following acute exercise in mice. Further, we also examined whether training status had an effect on EPO expression. Experiment 1 involved young healthy men (age, 21.4 ± 2.8 years; VO2peak, 47.1 ± 11.8 mL min−1 kg−1) from a previously published study (Edgett et al. 2016) who performed a single bout of exercise at ~55% of peak aerobic work rate for 1 hour. Muscle biopsies were obtained from the vastus lateralis at rest and 3 hours post‐exercise. Experiment 2 involved 8 week‐old male C57/B6 mice that were either exercise‐trained by treadmill running (1 hour/day, 4 days/week) or remained sedentary (untrained) for 5 weeks. Following the intervention, all mice performed an exhaustive exercise bout that began at a speed of 12 m/min with a 20‐degree grade; speed was subsequently increased by 1 m/min at 2, 5, 10, 20, 30 and 40 min, or until mice reached exhaustion. Soleus (oxidative muscle) and extensor digitorum longus (EDL, glycolytic muscle) were harvested at 1, 2 and 4 hours post‐exercise. All samples were analyzed by real‐time qPCR for changes in EPO mRNA expression. In agreement with a previous report, EPO mRNA expression increased 14 ± 5% in human skeletal muscle 3 hours post‐exercise. In experiment 2, EPO expression increased 4.1 ± 2.8 and 7.4 ± 1.7 fold at 1 hour post‐exercise in the soleus muscle of untrained and trained mice, respectively, before returning towards baseline. In EDL, post‐exercise EPO expression increased 4.1 ± 1.0 fold by 2 hours and plateaued thereafter in only untrained mice; this response was blunted in trained mice. Here we show that EPO expression increased post‐exercise in both glycolytic and oxidative murine skeletal muscles; training had a fiber‐type‐specific differential effect in these muscles. Future studies should determine the physiological significance of skeletal muscle‐derived EPO.Support or Funding InformationThis study was supported by funding from the Natural Sciences and Engineering Research Council of Canada (NSERC) to B.A.E., K.R.B., B.J.G. and J.A.S.