🔥Match Burners🔥 There appears to be a role for depletion of muscle glycogen - or rather a breach in a glycogen threshold as a key stimulus for a whole host of cell signalling responses involved in improvements in aerobic capability. The figure with the red and green bars is from the manuscript "fuel for the work required". It shows the proposed glycogen threshold as a shaded area along with statistically significant increases the activity of cellular signalling responses. My thinking is that if I can breach this glycogen threshold during training then I’m onto a winner. In the Arkinstall study, they provided participants with a diet containing 6 g/kg of carbs the day before cycling at 69% VO2max. Based on the starting muscle glycogen level it likely took around 45 min at that intensity to drop into the threshold zone. I can’t face doing an hour steady at 70% VO2max (even on Zwift) so this is my alternative. I used our gas analyser to estimate my substrate utilisation, in particular, my carbohydrate utilisation. Which I calculated to be 180 g. When I tested this I did 300:200 W but can easily do 10 min 30:30 @ 330:230 now with 10 min intervals at 270-280 W - all below 140 bpm (Zone 1). Based on the table above I estimated my muscle glycogen to be around 310 g. I used my carbohydrate intake in the previous 24 hours (6.2 g/kg) and the activity I’d done before to predict my leg muscle glycogen before the start of the session. I had a massive wobble around 40 min into the session - which is likely due to low levels of muscle glycogen/being a soft lad- so I had to have a word with myself (I don't get these wobbles now). I finished the session with 2 x 15 s max effort sprints with 15 s recovery between sprints repeated 4 times. I’m confident that sprint interval training is highly effective at inducing metabolic strain and the subsequent markers associated with cell signalling responses. So by combing the glycogen threshold hypothesis with sprint interval training, I feel like I’ve got a solid approach to improving my aerobic capabilities here. Time will tell. A batch of testing is coming soon! #redzonerunning #conditioning #sprints #sprinting #hiit (at Sheffield) https://www.instagram.com/p/BtkqpSZgph_/?utm_source=ig_tumblr_share&igshid=jpz7vf7jp5w7
