Nine real training days from a professional cyclist living with type 1, before there was a Blueprint. Each one is drawn against the ranges that rider's Blueprint found later.
9
real training days
26
hours on the bike
33%
of riding with a reading inside 90–130
40–398
mg/dL, lowest to highest
Ran low
Most of the time out of range was low: 38–55% of the day below 70.
Pick a day, zoom into the ride, and hover or tap the line for every reading. The shaded bands are the ranges the Blueprint found later.
GLUCOSE · mg/dL
POWER · WATTS (1-MIN MEAN)
HEART RATE · BEATS PER MINUTE
How to read this chart
This rider's range on the bike This rider's range before the ride (last 30 min)This rider's range for the rest of the day Hard line below Highest line on the bike Outside the rangeWell outside the rangeBelowAboveThe ridePower, 1-min mean (zoomed)Heart rate (zoomed)
A glucose sensor reads about 12 minutes behind your blood, so each reading is moved back 12 minutes to line up with the effort. A triangle marks a reading outside the range; a circle marks one well outside it. Purple means low, orange means high. Zoom to the session to see power and heart rate for every minute of the ride, under the glucose on the same clock, as members see them. These days were picked to show the spread, not the average. The ranges come from the Blueprint built later from this same record.
Every reading on this day (table view)
If your days have patterns like these, the Blueprint will find them and explain them.
Pre-ride rangeWhere glucose sat in the last 30 minutes before this rider's best rides: 130–160mg/dL. The Blueprint found it in this rider's own record.On-the-bike rangeWhere glucose stayed on this rider's best rides: 90–130mg/dL. Below 90 or above 160 counts as past a hard line.The night afterAcross this rider's record, each hour on the bike went with a night-time low about 4.8mg/dL lower. It's an observed pattern, not a rule: a long day pointed to a lower night.Less than half as fastWhen heart rate ran high but power didn't, glucose fell less than half as fast as when power was high, even on a pulse 23 beats a minute higher. The fall follows the work done, not the heartbeat.Per hour riddenEach hour on the bike went with a night-time low about 4.8mg/dL lower. After a rest day, 28% of nights went low (15 minutes or more in a row below 70, scored 22:00 to 07:00); after five hours or more on the bike, 54% did.The cost of a lowWith glucose below 70mg/dL, this rider held about 14 watts less than with glucose in the riding range (90–130), at the same point of a similar ride. It is the only glucose band that cost measurable power: hard drops that ended above 90 kept their watts.Glucose in the bloodAbout 4 grams circulates in a 70-kilogram adult, more or less with body size. The liver keeps the level steady, releasing glucose from glycogen and making new glucose as the tissues take it out. Source: Wasserman 2009Glucose in the blood, fallingWith both routes into the muscle open and injected insulin holding back the liver's release, glucose leaves the blood faster than it is replaced. Source: Riddell et al. 2017; Wasserman 2009Glucose in the blood, hours laterMuscles keep drawing glucose in to refill their glycogen, so blood glucose can drift down long after the ride, often overnight. Source: McMahon et al. 2007A skeletal muscle cellWorking muscle takes up most of the glucose used in exercise. It also holds the body's largest carbohydrate store, around 400 grams of glycogen, and keeps it: muscle can't release glucose back into the blood. Source: Hargreaves & Spriet 2020Inside the cellGlucose is phosphorylated by hexokinase the moment it enters, which traps it inside. At rest, most of it goes into glycogen. Source: Richter & Hargreaves 2013Inside a working cellGlycolysis splits glucose and glycogen into pyruvate for a little ATP, fast; in the mitochondria, with oxygen, each glucose yields about 30 ATP in all. The harder the effort, the bigger carbohydrate's share of the fuel. Source: Hargreaves & Spriet 2020RefillingAfter the ride the cell rebuilds the glycogen it burned, and stays more sensitive to insulin for many hours while it does. Source: Richter & Hargreaves 2013GLUT4, parkedGlucose transporters wait inside the cell in small vesicles. Until a signal brings them to the surface, little glucose gets in. Source: Richter & Hargreaves 2013GLUT4, moved by insulinInsulin's signal (the PI3K–Akt pathway) moves GLUT4 vesicles to the membrane, where they fuse and let glucose in. Source: Richter & Hargreaves 2013GLUT4, moved by contractionContraction moves GLUT4 by a separate signal (calcium and energy sensors such as AMPK) that needs no insulin. The two routes add up: a working muscle with insulin on board takes glucose in fastest. Source: Richter & Hargreaves 2013GLUT4, after the rideExercise's effect outlasts the ride: insulin brings more GLUT4 to the surface for many hours, one reason the night after can run low. Source: Richter & Hargreaves 2013; McMahon et al. 2007InsulinIt binds the insulin receptor on the muscle cell and starts the signal that brings GLUT4 to the surface. It also tells the liver to hold its glucose back. Source: Richter & Hargreaves 2013Injected insulinWithout diabetes, insulin falls as soon as exercise starts. Insulin already injected can't be turned down: it keeps GLUT4 at the surface and keeps holding the liver back, during the ride and after. Source: Riddell et al. 2017GlucagonNormally the first hormone to rise as glucose falls, telling the liver to release glucose. In type 1 this response is usually lost within a few years; adrenaline, the next defence, can be blunted by a recent low or hard exercise. Source: Cryer 2013Blood glucoseThe balance between what the liver releases and what the tissues take up. Without diabetes, hormones keep the two matched through exercise. Source: Wasserman 2009Blood glucose, fallingUptake now runs ahead of the liver's release, and nothing turns the injected insulin down, so the level drops, often faster than planned. Source: Riddell et al. 2017Blood glucose, the night afterIn one study of teenagers with type 1, the glucose needed to stay steady rose twice after afternoon exercise: straight after, and again 7 to 11 hours later. Source: McMahon et al. 2007The liverHolds around 100 grams of glycogen and releases glucose to keep the blood level steady, making new glucose when the store runs low. Source: Wasserman 2009The liver, held backInsulin tells the liver to hold its glucose back while the muscle takes glucose in. Source: Wasserman 2009The liver, still held backWithout diabetes, the liver releases more glucose as soon as exercise starts. Injected insulin keeps holding it back, during the ride and after. Source: Wasserman 2009; Riddell et al. 2017The liver, waiting for glucagonGlucagon is its main signal to release glucose fast. In type 1 it often doesn't come, and a long ride may already have run the liver's store down. Source: Cryer 2013; Wasserman 2009GlycogenGlucose stored in branched chains, around 400 grams across the muscles. The muscle keeps it for its own work. Source: Hargreaves & Spriet 2020Glycogen, fillingWith insulin's doors open, the glucose coming in is stored: the glycogen grows. Source: Richter & Hargreaves 2013Glycogen, in useUsed faster as the effort rises. Endurance falls as it runs low. Source: Hargreaves & Spriet 2020; Bergström et al. 1967Glycogen, refillingRebuilt after the ride, which is where much of the night's glucose goes. Source: Richter & Hargreaves 2013MitochondriaThe cell's furnaces. At rest they idle; with oxygen they can turn the pieces of each glucose into about 30 ATP. Source: Hargreaves & Spriet 2020Mitochondria, workingWith oxygen they turn the pieces of each glucose into about 30 ATP. Most of the ATP for a long ride is made here. Source: Hargreaves & Spriet 2020Below 70, on the bikeRiding with glucose below 70mg/dL, this rider held 14.4 watts less than at the same point of a similar ride with glucose in range, 90–130mg/dL. It is the only band clearly outside the record's margin of error. Source: The reference Blueprint: 10,652 ten-minute blocks of riding70–90, on the bike4.5 watts less than in range. Within the record's margin of error, so it could be chance. Source: The reference BlueprintIn range, on the bikeWith glucose at 90–110mg/dL this rider held 0.3 watts less, and at 110–130mg/dL 0.4 watts more, than across the range as a whole: in range, power held where it should. Source: The reference Blueprint: 10,652 ten-minute blocks of ridingAbove 220, on the bike4.4 watts less than in range. Within the record's margin of error, so it could be chance. Source: The reference BlueprintAfter a rest day28.1% of nights went low: 15 minutes or more in a row below 70mg/dL, scored 22:00 to 07:00. The typical lowest glucose overnight was 87.5mg/dL. Source: The reference Blueprint: 1,463 scored nightsAfter 5 hr or more on the bike54.1% of nights went low, and the typical lowest glucose overnight was 58mg/dL: about twice as many low nights as after a rest day. Source: The reference Blueprint: 1,463 scored nightsIn rangeThe share of the time on the bike that glucose stayed inside the riding range, 90–130mg/dL.LowestThe lowest sensor reading of the day. The sensor reads no lower than 40, so "40 or below" means it may have gone lower.On the bikeTime on the bike, from the start of the ride file to its end.Nine daysReal training days from this rider's record, picked to show the spread: three that ran low, three that stayed in range, three that ran high.Hours on the bikeAll the riding across the nine days, added up.Inside the rangeOf the riding time with a sensor reading, the share that stayed inside the riding range the Blueprint later found, 90–130mg/dL.Lowest to highestThe lowest and highest sensor readings across the nine days. 40 is as low as the sensor reads.Pre-rideThe last reading just before the ride started, against the pre-ride range, 130–160mg/dL.Daytime in rangeThe share of readings from 07:00 to 22:00 inside 70–180mg/dL, the range most often used for everyday time in range.Lowest the night beforeThe lowest reading between midnight and 07:00 before the ride. Below 70mg/dL counts as low.Time past a hard lineMinutes past a hard limit. On the bike: below 90 or above 160. In the 30 minutes before: below 90 or above 220. The rest of the day: below 70 or above 220.