STRYD Tests: Varying Terrains & Speeds

More tests today. Here are some results and inferences.

Test 1: Flat, constant speed, Varying surfaces

• Tarmac: 3:59/km, 260w
• Firm track: 3:53/km, 260w
• Grass, mildly soft: 3:59/km, 264w

My Inferences: Surface appears not to be taken into account.

Test 2: How does power increase with pace? Exactly the same external conditions for each interval.

• 3:20/km, 269w
• 3:41/km, 263w
• 3:45/km, 258w
• 4:09/km, 256w
• 4:36/km, 239w
• 4:42/km, 242w (?)

My Inferences: Looks fairly linear to me. [I had the pleasure of Dr Andrew Coggan confirming to me on a forum that this should be expected in normal power ranges as VO2 increases linearly with speed/pace]. I would not have thought that, so it’s always good to learn.

Test 3: Extended Uphill – same gradient (relatively gentle but enough to slow us all down) and wind, different surface

• TARMAC – 4:24/km, 280w
• SOFT, BUMPY GRASS – 4:25/km, 270w

My Inferences: Looks wrong to me. Possible some element of my technique may have changed??

Test 4: Medium Downhill (relatively gentle), sheltered, different surfaces.

• TARMAC – 3:18/km, 275w
• SOFT, BUMPY GRASS – 3:23/km, 281w

My Inferences: Inconclusive. Initially I thought that this looks wrong but possibly correct. I would have expected much more power required as ground was soft. Yet I ran slightly slower and required 6w more on the bumpy grass. BUT had I ran at 3:18/km/h on the bumpy grass then maybe the watts would have been a fair bit more +10w? That would then look more sensible I guess.