The invitation is to a better experience of life with diabetes.
Either way, it starts in the muscle.
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Where glucose goes when you exercise.
You came for the watts. Find out where you can keep them.
You came for steadier rides.
01
In the blood
Glucose travels in your blood. To fuel a muscle, it has to get inside the cell.
The science
There are only about 4 grams of glucose in the blood of a 70-kilogram adult at any moment, roughly a teaspoon; more or less with body size. The liver keeps it topped up, releasing glucose from its own glycogen store (around 100 grams) and making new glucose when that runs low. Muscles hold the body's biggest carbohydrate store, around 400 grams of glycogen, but they keep it for themselves: they can't release it back into the blood.
Insulin is the key. It tells the cell to bring its glucose doors to the surface.
The science
Insulin binds to receptors on the muscle cell and sets off a signal inside it. Glucose transporters called GLUT4, parked in small sacs inside the cell, move up and fuse with its surface. Glucose then passes in, and is immediately tagged (phosphorylated) so it can't leak back out. From there it is either stored as glycogen or burned.
Exercise opens the same doors on its own. A working muscle pulls glucose in without needing insulin.
The science
A contracting muscle moves GLUT4 to its surface by a separate signal (calcium and energy sensors such as AMPK), with no insulin needed, so uptake can rise many times over. Inside, glucose and the muscle's own glycogen are split by glycolysis, which yields a little ATP fast; the pieces then enter the mitochondria, where oxygen turns each glucose into about 30 ATP in all. ATP is what makes the muscle fibres contract. The harder the effort, the more the muscle leans on carbohydrate.
Without type 1, the body turns insulin down when you ride. With type 1, the insulin you injected keeps working, so both doors stay open and glucose can fall faster than you planned.
The science
Without diabetes, the pancreas cuts insulin and raises glucagon as soon as you ride, so the liver releases more glucose and supply keeps pace with what the muscles take. Injected insulin can't be turned down once it's in: it keeps the insulin door open and also holds back the liver's release. Uptake runs ahead of supply, and blood glucose drops.
And the body's usual backup against a low often doesn't step in.
The science
When glucose falls, the body's first defences are less insulin and more glucagon, which tells the liver to release glucose from its glycogen, with adrenaline behind it. In type 1 the glucagon response to a falling glucose is usually lost within a few years, and a recent low or hard exercise can blunt the adrenaline response as well. The liver's store may also already be run down by a long ride.
Sources: Cryer 2013, N Engl J Med 369:362; Riddell et al. 2017
06
The night after
After the ride, your muscles keep refilling, and insulin works harder for hours. That's the night after.
The science
After the ride, muscles refill the glycogen they burned, and they stay more sensitive to insulin for many hours while they do it. Glucose keeps flowing into them long after the effort has stopped. In one study of teenagers with type 1, the glucose needed to stay steady rose twice after afternoon exercise: straight after, and again overnight, 7 to 11 hours later.
That's the gap. Your Blueprint shows how your own body handles it: pre-ride, on the bike, and the night after.
The science
Every step above differs from one body to the next. Those differences show up in your own record. The Blueprint describes, from your glucose and training files, where your best rides started, where they stayed, and what the nights after looked like.
Sources: The reference Blueprint (Type1 Athletics)
Pre-ride, where the best rides started
130–160mg/dL
On the bike, where the best rides stayed
90–130mg/dL
The night after
−4.8mg/dL off the low per hour ridden
Glucose below 70
−14.4watts on the bike
In range, 90–110 and 110–130
−0.3 / +0.4watts
Glucose above 220
−4.4watts on the bike
Against the 90–130 range as a whole; only below 70 clears the margin of error.
On the bike, where the best rides stayed
90–130mg/dL
After a rest day
28%of nights went low
After 5 hr or more on the bike
54%of nights went low
A low night: 15 minutes or more in a row below 70, 22:00 to 07:00.
Before the Blueprint
The days you don't see coming.
Real training days from a professional cyclist living with type 1, before there was a Blueprint. Here is one of them, hour by hour.
00:00Training day 2
NightPre-ride130–160On the bike90–130After70130180250mg/dL
00:0006:0012:0018:0024:00
The night before
Overnight, glucose fell to 44mg/dL. The day starts on the back foot before the bike is even out.
Pre-ride
Just before the start: 114mg/dL. The Blueprint this rider got later found the best rides started at 130–160.
On the bike
4 hr 9 min of riding. Inside the 90–130 range that Blueprint later found for the bike 40% of the time, and down to 60mg/dL at the lowest.
After the ride
At 18:28, 4 hr 16 min after finishing, glucose reached 40mg/dL, as low as the sensor reads. The ride was over; its effect wasn't.
With a Blueprint
None of those moments had a reference. The Blueprint gives each one its own, found in your own rides.
The ranges your best pre-rides, rides and nights fell in, and how sure each one is.
Put it to work
On your own in the member dashboard, or with coaching, when the member platform opens.
The Blueprint is the membership: your own ranges in the member dashboard, opening soon.
Endurance coaching (Foundation, On-Going and Full) is built on it. Foundation includes your first month of Blueprint, which then continues at €15/month (VAT included) until you cancel; On-Going and Full include it while you're coached.
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.
