Long-chain fatty acids (LCFA) from plasma and from lipolysis of intramyocellular triacylglycerol (IMTG) both serve as fuel for energy production. It is evident that the control of LCFA utilization in skeletal muscle is complex and is subject to a plethora of regulatory mechanisms that have different degrees of importance at rest and during exercise. From studies using genetic manipulation of FAT/CD36, it seems that FAT/CD36 is an important component in the control of plasma LCFA uptake and utilization in skeletal muscle during exercise and the molecular mechanisms behind FAT/CD36 trafficking is central in understanding how LCFA utilization is regulated. The mobilization of fatty acids from the IMTG pool is catalyzed by three lipases:adipose triglyceride lipase (ATGL), hormone sensitive lipase (HSL), and monoacylglycerollipase (MAGL) which sequentially degrade TG, diacylglycerol (DAG) and monoacylglycerol (MAG), respectively. In skeletal muscle, HSL has for long time been considered to be the primary lipase activated by contractions. This notion was based on in vitro activity measurements, where the contraction induced increase in TG-lipase activity was completely blocked when adding an HSL-antibody to the assay medium. However, the in vitro activity assay does not include changes in important regulatory events such as translocation of lipases to the lipid droplets and interaction with lipid droplet associated proteins, and therefore may not entirely reflect the acute activation of muscle TG-lipases in vivo. In addition, in several human studies dissociations between in vitro HSL activity and net change in IMTG content during exercise have been observed. This may reflect that lipases other than HSL are at play. Knowledge about ATGL in skeletal muscle is limited, but ATGL protein expression and activity have been demonstrated in both rodent and human skeletal muscle. The functional importance of ATGL for basal TG-hydrolysis in skeletal muscle is highlighted by the finding of massive IMTG-accumulation in ATGL-KO mice. These data strongly suggest that ATGL has an important role for skeletal muscle TG-hydrolysis. Furthermore, recent data suggest that ATGL is also activated in skeletal muscle during contractions and plays a major role in breakdown of IMTG.