Running hills (terrain) 14:00 [5]
10 by 30 seconds with 60 seconds rest. Legs feeling really good but got the pain in my chest again, thought it was a stitch to start with - it felt like it was in my left shoulder - but it didn't go away. Only really noticed it when breathing in. Didn't impinge too much on my speed, but had too push through. Might be something to do with some bad posture because I'm sat revising all day.