Fig. 2: ¹H-Magnetic resonance spectroscopy of total, saturated and unsaturated intramyocellular lipid bonds.

2A: Top: Representative localisation of the spectroscopy voxel for ¹H-magnetic resonance of the right vastus lateralis. Middle: Colour-coded schematic showing protons connected to carbon nuclei in single (saturated) covalent bonds in blue and red and protons connected to double/triple (unsaturated) carbon bonds or adjacent to double/triple bonds, which are shown in green and purple, respectively. Bottom: The same colour-coding shows how the different proton species process at different frequencies in the magnetic field, generating different spectral peaks as shown by the different chemical shifts (parts per million, ppm) of saturated (0.9 ppm, 1.3 ppm) and unsaturated (2.1 ppm, 5.2 to 5.3 ppm) intramyocellular lipid peaks. Main extramyocellular lipid (EMCL) peak is separated at 1.5 ppm (yellow). 2B: Intramyocellular total lipids and fractions of saturated and unsaturated carbon bonds within intramyocellular lipid (n = 25 athletes and n = 22 patients with type 2 diabetes), Arb U = arbitrary units. Data is shown as individual data points with means and error bars for standard deviation. Baseline and post-interventions comparisons between groups were performed using t-tests. Top: Intra-myocellular fractional lipid mass in athletes and type 2 diabetes patients before and after exercise intervention Middle: Intra-myocellular fraction of saturated lipids in athletes and type 2 diabetes patients before and after exercise intervention. Bottom: Intra-myocellular fraction of unsaturated lipids in athletes and type 2 diabetes patients before and after exercise intervention.