Interactive tools to help people with diabetes understand how insulin, food, and exercise interact to affect blood glucose.
Available Simulators
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Bolus Timing Simulator
See how the timing of your insulin bolus relative to meal start affects blood glucose. Learn about pre-bolusing and timing for different meal types.
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Split Bolus Simulator
Explore how splitting a bolus into two doses at different times can better match insulin action to the extended absorption of high-fat meals.
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Temp Basal Simulator
For insulin pump users: see how adjusting your basal rate before, during, and after exercise affects blood glucose management.
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Exercise Timing Simulator
Understand how exercise lowers blood glucose and how the timing of food and insulin around workouts affects your response.
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Extended Exercise Simulator
Plan for long workouts of 4+ hours. Model pre-exercise fueling, in-exercise nutrition, pump temp basals, and post-exercise recovery.
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High-Intensity Exercise Simulator
See how sprints and intense intervals raise blood sugar during effort, then create a delayed low risk hours later — the opposite of moderate exercise.
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24-Hour Diabetes Simulator
Combine boluses, meals, exercise, and temp basals across a full day. See how decisions stack and compound — from morning dawn phenomenon to overnight sensitivity.
Open Simulator →
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Bolus Timing Simulator
Move the slider to see how insulin timing relative to meal start affects blood glucose.
When you eat, your blood sugar rises. When you take insulin, your blood sugar falls. That sounds simple, but timing of insulin in relation to eating impacts how blood sugars change during that process.
This chart is designed to help you visualize how insulin absorption and food digestion overlap over time with carbs or high fat meals. By adjusting when insulin is given relative to when food is eaten, you can see how different timing strategies may change the shape of your blood sugar curve.
Pay attention to:
What happens when insulin peaks before the carbs hit?
What happens when carbs rise before insulin peaks?
How does adding fat to a meal change the curves?
What's happening here?
Fast-acting insulin starts working about 10 minutes after injection, peaks around 60–90 minutes, and stays active for up to 6 hours. It does not follow a sharp on/off curve — it ramps up slowly, reaches a peak, then tapers off gradually.
Food digests at a different rate than insulin works. Carbohydrates raise blood sugar faster than insulin can pull it down. Fat and protein slow that absorption considerably.
When you bolus early (pre-bolus)
Insulin begins working before carbs are digested, which can blunt or prevent the post-meal spike
Bolusing too far ahead can cause blood sugar to drop before food absorbs, especially with lower-carb or mixed meals
Pre-bolusing works best with fast-digesting, carbohydrate-heavy meals
When you bolus late or at meal start
Carbs absorb while insulin is still ramping up, which often causes a spike before insulin brings it back down
For high-fat meals, a later bolus may better match the slower digestion curve
A late bolus rarely causes the same early low risk as a pre-bolus does
Applying this to your own life
Track what happens with different bolus timing for the meals you eat most often. A CGM makes this easy — look at the curve 1–3 hours after eating. Over time, you will develop a feel for how much lead time each type of meal needs.
Keep notes on:
Which meals benefit from a 15–30 minute pre-bolus
Which meals cause an early drop when pre-bolused
How the curve differs between carb-heavy and high-fat meals
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Split Bolus Simulator
See how splitting your dose across two injections — or using an extended bolus on a pump — can improve coverage for high-fat and mixed meals.
A split bolus divides your total insulin dose into two parts delivered at different times. The goal is to better match how insulin acts to how food absorbs — especially for high-fat meals that digest slowly and raise blood sugar over several hours rather than all at once.
MDI users (injections) do this by giving two separate injections: one at meal start and a second 60–90 minutes later. Pump users achieve the same result with an extended bolus: an immediate upfront portion delivered all at once, followed by the remainder spread evenly over a set duration in small pulses every few minutes. The effect on blood sugar is nearly identical — the difference is just in how the second portion is delivered.
Pay attention to:
What happens when most insulin is given upfront for a high-fat meal?
What happens when too much insulin is delayed or extended?
How does spreading the second portion over a longer duration change the insulin curve?
What's happening here?
Fast-acting insulin peaks around 60–90 minutes after injection. A single upfront dose concentrates most of its action in the first two hours. For a high-fat meal that absorbs over 4–6 hours, this creates a mismatch: insulin acts early, food absorbs late — resulting in an early drop followed by a late rise.
Splitting the dose spreads insulin action across a longer window, better matching that slower absorption curve.
For carbohydrate-heavy meals
A single dose given 15–30 minutes before eating usually provides good coverage
Splitting is usually not necessary and can add complexity without benefit
A well-timed pre-bolus often outperforms a split for fast-absorbing meals
For high-fat or mixed meals
Fat slows digestion, so a large upfront dose can cause an early low before food absorbs
Giving part of the dose upfront and the rest 60–90 minutes later — or spread over 1.5–3 hours on a pump — can better follow the slower rise
A common starting point is 50–60% upfront with the remainder delayed or extended
MDI vs. pump extended bolus
MDI: Give two separate injections — one at meal start, a second 60–90 minutes later when the food is clearly absorbing.
Pump extended bolus: The immediate portion is delivered like a normal bolus; the extended portion is dripped in automatically over your chosen duration in small pulses every few minutes.
The blood sugar effect is nearly identical — the pump just automates what MDI does manually, and allows finer control over the delivery window.
Applying this to your own life
Split and extended bolusing works best for meals where you consistently see a late rise — often 2–4 hours after eating — despite good early coverage. Pizza, pasta with cream sauce, and high-fat restaurant meals are common examples.
Keep notes on:
Which meals consistently cause a late rise even with a well-timed bolus
Whether delaying part of the dose reduces that late rise
For pump users: whether a 1.5–3 hour extended duration smooths the curve better than a single second injection would
How the split percentage affects the shape of the curve for your specific meals
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Temp Basal Simulator
For pump users: see how adjusting your basal rate around exercise affects blood glucose.
Insulin pumps deliver basal insulin as small, continuous pulses of fast-acting insulin. A temporary basal rate lets you reduce or increase this delivery for a set period of time.
This chart is designed to help you visualize how adjusting your basal rate before, during, and after exercise changes insulin delivery and blood glucose — especially when combined with food and the glucose-lowering effect of exercise itself.
Pay attention to:
What happens when you reduce basal too late before exercise?
What happens when you reduce it too much or too early?
How does food interact with the temp basal effect?
What's happening here?
Insulin pumps deliver basal insulin as rapid micro-pulses of fast-acting insulin, unlike MDI users who inject a slow-acting basal insulin once or twice a day. This means pump basal can be adjusted in real time — increased, decreased, or suspended — to respond to changing circumstances like exercise.
A temporary basal rate reduces or increases this ongoing delivery for a set period. Because each micro-pulse of fast-acting insulin has the same absorption curve as a bolus, the timing of the rate change matters as much as the magnitude.
Why timing matters
Fast-acting insulin from a temp basal change takes 15–30 minutes to start reducing delivery and 60–90 minutes to reach peak impact
Setting a temp basal at the start of exercise is often too late — the insulin from the minutes just before exercise is already absorbed and active
Starting a reduced basal 60–90 minutes before exercise gives the change time to take effect before activity begins
What happens when basal is reduced
Less fast-acting insulin is delivered over time, so the ongoing pull on blood sugar decreases
Blood sugar tends to drift upward if basal is reduced for long enough
The exercise-driven glucose uptake partially offsets this rise, but the balance is different for every individual
What happens after exercise
Returning to normal basal while insulin sensitivity is still elevated can cause a drop
Some people maintain a reduced basal for 1–2 hours after finishing to account for lingering sensitivity
Food eaten post-workout will also have a smaller insulin requirement than usual
Applying this to your own life
Temp basals require experimentation. Start with a modest reduction (50–70%) beginning 60–90 minutes before exercise, and track what happens to blood sugar during and after.
Keep notes on:
What time before exercise you set the temp basal and how blood sugar responded
Whether the exercise-driven drop was blunted, eliminated, or whether you went high instead
How long after exercise your blood sugar continued to trend down, and whether a reduced basal post-workout helped
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Exercise Timing Simulator
For aerobic and low-to-moderate intensity exercise: see how food and insulin timing interact with the glucose-lowering effects of a workout.
Exercise causes muscles to absorb glucose directly — with or without insulin. That means blood sugar can drop during a workout even if you have no insulin on board. When you do have insulin active, exercise amplifies its effect.
This chart is designed to help you visualize how the timing of food and insulin around exercise changes the blood sugar curve before, during, and after a workout.
Pay attention to:
What happens when you start exercise with insulin on board?
What happens when you eat carbs before exercise without taking insulin?
How does the timing of food and your bolus change the curve before, during, and after?
For high-intensity interval training and sprints, see the High-Intensity Exercise simulator →
What's happening here?
During aerobic exercise, your muscles can absorb glucose without insulin — a direct, insulin-independent uptake that causes blood sugar to drop regardless of how much insulin is on board. The harder and longer you exercise, the more pronounced this effect.
When you also have insulin active during exercise, the two effects compound. Exercise accelerates insulin absorption from the injection site, meaning insulin peaks sooner and acts more strongly than it would at rest. This combination — glucose uptake by muscle plus faster-acting insulin — can cause a rapid drop.
Before exercise
A large bolus 1–2 hours before a workout will still be near its peak when exercise starts, compounding the glucose drop
Eating carbs without a bolus can raise blood sugar before exercise, which then acts as a buffer against the exercise-driven drop
Starting exercise with no insulin on board and no food means blood sugar may drop from muscle uptake alone
During exercise
Blood sugar typically falls throughout the workout, faster if insulin is active
Fueling with fast-acting carbs during the workout can offset the drop
The rate of drop depends heavily on how much insulin was taken before and when
After exercise
Insulin sensitivity remains elevated for hours after a workout — sometimes up to 24 hours
The same dose of insulin lowers blood sugar more than it would at rest
Meals and corrections in the hours after exercise often need to be smaller than usual
Applying this to your own life
Watch what happens to your blood sugar in the 2–3 hours before, during, and after workouts. The patterns repeat, but they depend on how much insulin is on board when you start.
Keep notes on:
What your blood sugar does during different types of workouts
Whether pre-workout carbs help keep blood sugar stable, and how much
Whether you notice lows 2–6 hours after exercising — this is the elevated sensitivity window
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Extended Exercise Simulator
Model blood glucose across a 4-hour workout: pre-exercise preparation, in-exercise fueling, and post-workout recovery.
Long workouts lasting four or more hours deplete glycogen stores, increase insulin sensitivity, and require active fueling strategies to maintain blood glucose. The effects extend well beyond the exercise window itself.
This chart is designed to help you visualize how pre-exercise fueling, in-exercise nutrition, pump temp basals, and post-exercise recovery all interact across the full timeline of a long workout.
Pay attention to:
What happens when pre-exercise fueling is low or insulin on board is high?
How does continuous in-exercise fueling change the curve during the workout?
What does the post-exercise persistent decline look like, and why does it matter overnight?
What's happening here?
Extended exercise changes how both insulin and carbohydrates behave in your body. Muscles run primarily on glycogen — a form of glucose stored in muscle tissue and the liver. At sustained effort, your body burns through that glycogen steadily, and stores typically last around 90–120 minutes before they start running low. Once glycogen is depleted, performance drops sharply and blood sugar becomes harder to maintain.
This is why fueling during long workouts isn't optional — it's not just about managing blood sugar, it's about keeping your muscles supplied with the energy they need to keep going. The good news: during aerobic exercise, working muscles can pull glucose directly from the blood without needing insulin to do it. That means carbs you eat during the workout go largely straight to the muscles, so you need far less insulin to cover in-exercise fueling than you would for the same amount of carbs eaten at rest.
Important — insulin does more than lower blood sugar: Most people only think about insulin when blood sugar is high, but your body needs insulin continuously — even when blood glucose is normal. Every cell in your body uses glucose as fuel, but glucose can't get into cells without insulin acting as a "key" to unlock the door. Without it, cells are forced to burn fat for energy instead, producing acidic byproducts called ketones. If ketones build up faster than the body can clear them, the blood becomes dangerously acidic — this is diabetic ketoacidosis (DKA). DKA is caused by a lack of insulin, not by high blood sugar, and it can develop even when blood glucose looks normal. For pump users especially, suspending insulin for more than a few hours removes all background coverage and creates real DKA risk.
Phase 1
Before Exercise
Fueling before a long workout tops off glycogen stores. Carbohydrates are stored as glycogen in muscles and the liver — once those stores run out, performance drops and blood sugar becomes harder to control.
Phase 2
During Exercise
Working muscles absorb glucose directly without needing insulin. This means less insulin is required to cover in-exercise carbs, and any insulin already on board has a much stronger effect than usual.
Phase 3
After Exercise
Muscles and liver continue pulling glucose to replenish depleted glycogen. Increased insulin sensitivity can last many hours — sometimes up to 24 hours.
During exercise (4 hours)
The same amount of insulin lowers blood sugar more than usual.
If fueling is too low, blood sugar may drop steadily throughout the workout.
If fueling matches muscle demand and insulin is appropriately adjusted, blood sugar may stay stable.
After exercise (post-workout)
Blood sugars trending lower in the hours after finishing.
Reduced insulin needs for meals eaten after exercise.
Increased risk of delayed lows, especially overnight.
The day after
Muscles and liver continue restocking glycogen for 24–48 hours, pulling glucose out of the bloodstream even when you're at rest.
Insulin sensitivity may remain elevated the next morning — breakfast and correction doses can hit harder than usual.
Overnight lows are most common after a long afternoon or evening workout when dinner insulin and the post-exercise effect overlap.
A small bedtime snack or reduced overnight basal can help bridge the gap between the post-exercise effect and waking up in range.
MDI vs Pump
MDI users rely on long-acting basal insulin, which cannot be adjusted quickly. Pump users can adjust basal rates, but changes take time due to absorption. This is why temp basal reductions often need to start 90–120 minutes before exercise begins.
Applying this to your own life
Extended workouts require planning in three phases:
Before: Evaluate insulin on board, adjust pump basal early if needed, fuel to support glycogen stores.
During: Fuel regularly, monitor trends, remember less insulin is needed but not zero insulin.
After: Expect increased insulin sensitivity, consider reduced bolus doses, watch for delayed lows especially overnight.
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High-Intensity Exercise Simulator
See how sprints, heavy lifts, and interval training create a different blood glucose pattern than moderate exercise.
High-intensity exercise above roughly 85% of your maximum heart rate triggers a stress response that temporarily raises blood sugar — even while you are burning fuel at a very high rate. This makes it one of the most counterintuitive situations in diabetes management.
This chart is designed to help you visualize how blood glucose, insulin on board, and insulin sensitivity interact during and after a short, intense workout.
Pay attention to:
Why blood sugar rises during and just after a high-intensity effort
When the glucose spike peaks and begins to fall
Why the hours after the workout carry a hidden low risk despite the earlier high
What's happening here?
During high-intensity exercise, your body releases stress hormones — primarily adrenaline and cortisol — that signal your liver to release stored glucose rapidly. This release outpaces how fast your muscles can use it, so blood sugar rises even though you are working hard.
Unlike moderate exercise, which typically lowers blood sugar during the workout, high-intensity effort can push blood sugar up significantly. The rise often peaks 5–15 minutes after the hardest effort ends, not during it.
Important: The post-workout high is temporary. Giving a large correction bolus during this window can cause a significant low 1–3 hours later as insulin sensitivity spikes during recovery.
Phase 1
During Effort
Stress hormones cause the liver to release glucose faster than muscles can absorb it. Insulin on board is temporarily less effective. Blood sugar rises.
Phase 2
Early Recovery
Stress hormones clear. Blood sugar peaks and begins falling. Insulin on board starts working more effectively — sometimes more than expected.
Phase 3
Late Recovery
Depleted muscles pull glucose from the blood to replenish stores. Insulin sensitivity is significantly elevated. The risk of a delayed low is highest here.
During the workout
Stress hormones cause the liver to release glucose faster than muscles can absorb it
Insulin on board is less effective than usual — your body is temporarily more resistant to insulin during peak effort
Subcutaneous insulin may absorb slightly slower during peak effort due to reduced skin blood flow
Immediately after (0–60 minutes)
Stress hormones begin to clear, and blood sugar starts falling from its peak
Insulin on board begins working more effectively as resistance fades
Any correction bolus given for the post-workout high will act faster and stronger than it would at rest
Later after (1–6 hours)
Muscles that were depleted during the workout begin pulling glucose to replenish their stores — with or without insulin
Insulin sensitivity is significantly elevated, meaning the same dose lowers blood sugar much more than usual
This is the window where a correction given for the earlier high can cause a significant low
The day after
Insulin sensitivity can remain elevated for up to 24–48 hours after intense exercise
Meals and corrections during this window may need smaller doses than usual
Applying this to your own life
High-intensity workouts create two separate management challenges that happen back to back: a high during and just after the effort, followed by an elevated low risk in the hours that follow.
When doing intense workouts, watch how your blood sugar responds during the workout itself and for several hours afterward. A CGM is especially useful here because the delayed low can happen well after the workout feels finished.
As you make observations, keep notes on:
How high your blood sugar rises and how long the peak lasts after you finish
How quickly it falls in the first hour after you stop
Whether you notice lows 2–6 hours later, and whether they happen during sleep if you worked out in the evening
How your next meal's insulin needs compare to a day when you didn't work out
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24-Hour Diabetes Simulator
See how food, insulin, and exercise interact across an entire day — and how decisions made in the morning shape what happens at night.
Every simulator on this site isolates one variable at a time — a single bolus, one workout, a temp basal change. In real life, all of those things happen on the same day, and the effects compound in ways that aren't always intuitive. A workout at noon changes how your evening meal behaves. A temp basal set hours before exercise still has insulin on board during it. Multiple workouts mean glycogen depletion carries forward from one session to the next.
This simulator lets you build an entire day from scratch using the same underlying math as all the other simulators. Add boluses, meals, exercise sessions, and (if using a pump) temp basals at any time in the 24-hour window. The effects stack and compound exactly as they would in your body.
New here? If the chart looks overwhelming, start with the individual simulators to learn each effect in isolation — then come back here to practice combining them.
Pay attention to:
How multiple workouts interact — glycogen depleted in one session affects the next.
The dawn phenomenon: a predictable blood sugar rise at wake time that needs to be planned for each morning.
Overnight insulin sensitivity: a significant workout day means your basal insulin may be more effective while you sleep, increasing the risk of nocturnal lows.
Note: you can only add up to 6 of any one type of entry.
What's happening here?
The chart shows blood glucose effects across a full 24-hour day, from your selected wake time back to the same wake time the next day. The darker shaded region is your sleep window. The chart starts flat — all the BG change you see comes from entries you add.
Dawn phenomenon
Starting at wake time, cortisol and growth hormone naturally drive the liver to release glucose — a phenomenon called the dawn effect. In people with type 1 diabetes, there is no automatic compensating insulin response, so BG rises predictably each morning. The size of the rise varies by person, but it is nearly universal. Most people need to account for this with a morning bolus or, on a pump, a higher pre-dawn basal rate.
Compounding exercise effects
When you exercise more than once in a day, the effects stack. The post-exercise sensitivity from your first session may still be active when your second workout begins. More importantly, glycogen stores depleted during the first workout have to be replenished through food before the next session — otherwise your muscles are drawing from an already-depleted reserve, making the blood sugar drop during exercise larger and faster than expected.
Overnight insulin sensitivity
Research consistently shows that moderate-to-heavy exercise increases insulin sensitivity for 12–24 hours afterward, including during sleep. For people on insulin, this means the same basal rate that kept blood sugar stable the night before a workout day may cause low blood sugar the night after. The effect is proportional to how much you exercised — a light 30-minute walk has minimal effect, while a hard hour-long run or a long bike ride can meaningfully shift overnight sensitivity.
MDI vs Pump
MDI users have long-acting basal insulin that cannot be adjusted once injected — the only tools are timing and amount of fast-acting doses, and food. Pump users can add temp basals at any point to adjust delivery up or down, giving more flexibility around exercise, meals, and overnight patterns.
Applying this to your own life
The goal of the individual simulators is to help you understand each effect in isolation. The goal of this one is to help you understand how they interact. Use them in that order.
Start with the individual simulators: Use Bolus Timing, Split Bolus, Exercise Timing, and the others to build intuition for each effect in isolation — then come back here to practice combining them. If you see something in the 24-hour chart you don't understand, open the specific simulator for that effect.
Match the simulator to your day: Think of a real day you've had — a workout, a meal that didn't go as expected, a late correction bolus — and try to recreate it here. See if the chart reflects what you actually experienced.
Keep notes: When you notice a pattern in your own data — lows on workout evenings, a stubborn high every morning — bring that question to the simulator. Try different combinations and see what the model suggests.
Try things you wouldn't try in real life: This is a simulation. Setting a temp basal two hours before exercise and seeing how it plays out costs nothing here. Build the intuition before you need it.
How These Simulators Work
Food, insulin, and exercise all operate at different speeds — and those change when they overlap. These tools make those invisible processes visible so you can learn to anticipate them.
What you're looking at
Each chart shows relative effects — how a factor moves blood sugar compared to a flat baseline. No actual blood sugar numbers appear, because everyone's starting point is different. The shape of the curve is what matters: when it peaks, how long it lasts, and how it overlaps with other effects.
Not medical advice. These are learning tools, not management tools. Talk to your care team before making any changes to your insulin or exercise routine.
Each simulator is a sandbox for one concept. Start with the individual simulators to build intuition for each effect. When you're ready, the 24-Hour Simulator → lets you combine everything and see how they interact across a full day.
What each toggle shows
The buttons above each chart let you show or hide individual effects. Here's what each one represents.
Carb Effect
Food raises blood sugar
Carbohydrates digest into glucose and enter the bloodstream. Fast-absorbing carbs (juice, glucose tablets) hit quickly. Complex carbs, fat, and protein slow the process down — which is why the same amount of food can produce very different curves depending on what's in it.
Insulin Effect
Insulin lowers blood sugar — slowly
Fast-acting insulin starts working about 10–15 minutes after injection, peaks around 60–90 minutes, and stays active for up to 6 hours. It never acts instantly. Where you are in that curve when you eat or exercise changes everything.
Basal Effect
Background insulin rate (pump only)
Insulin pumps run a continuous background dose all day. A temp basal change — higher or lower — takes 60–90 minutes to reach full effect. What you see is how that change compares to your normal baseline rate.
Exercise Effect
Muscles pull glucose during a workout
During aerobic exercise, working muscles absorb glucose directly from your blood — without needing insulin to do it. Blood sugar drops during the workout, and the drop is faster if insulin is also active. Harder effort means faster glucose uptake.
Post-Ex Effect
Recovery pulls glucose for hours after
After a workout ends, your muscles and liver continue pulling glucose from the blood to replenish depleted stores. This can last up to 24 hours. It's the main reason meals after a hard workout often need less insulin than usual — and why overnight lows happen on workout days.
Dawn Effect
Morning hormones raise blood sugar every day
Each morning, cortisol and growth hormone signal your liver to release stored glucose to fuel the start of the day. In people without diabetes, the pancreas compensates automatically. Without that response, blood sugar rises predictably every morning — whether you eat or not.
Overnight Sensitivity
Exercise makes insulin more effective overnight
After significant exercise, your body becomes more sensitive to insulin during sleep — the same dose lowers blood sugar more than it normally would. The harder you worked that day, the stronger the effect. It's one of the most common causes of unexpected overnight lows on workout days.
The four main drivers of blood sugar
Insulin is what lets your cells use glucose for energy. Fast-acting insulins — sold as Humalog (lispro), Novolog (aspart), and Fiasp (faster aspart) — take time to work and stay active for hours. Long-acting insulins — Lantus/Basaglar/Toujeo (glargine), Levemir (detemir), Tresiba (degludec) — provide a slow background throughout the day. Insulin pumps use only fast-acting insulin for both background and meal doses.
Your body needs some insulin at all times — not just when blood sugar is high. Without it, cells can't use glucose and begin burning fat instead, producing acidic byproducts called ketones. When ketones accumulate too fast, it becomes life-threatening (diabetic ketoacidosis, or DKA). DKA is caused by too little insulin, not high blood sugar — it can develop even when glucose looks normal, especially for pump users who suspend insulin for extended periods.
Carbohydrates raise blood sugar by converting to glucose during digestion. Speed depends on the type — pure sugars absorb in minutes, complex carbs take much longer. Fat and protein slow digestion, so a high-fat meal produces a very different curve than a bowl of rice with the same carb count. Fast-acting carbs (glucose tablets, juice) are the right tool for raising a low quickly — complex food is not.
Exercise lowers blood sugar by allowing muscles to absorb glucose directly, without insulin. It also increases insulin sensitivity for hours afterward. High-intensity exercise works differently — stress hormones cause the liver to dump glucose, temporarily raising blood sugar during the effort before the drop comes later.
Your liver stores glucose as glycogen and releases it when your body needs energy. Stress hormones — adrenaline during intense effort, cortisol during illness or anxiety — trigger a glucose release automatically. This is one of the main reasons blood sugar can move unexpectedly without any food or insulin changes.
About Beta Cell Foundation
We build free educational tools that help people with diabetes understand what's happening inside their bodies.
Vision
We believe managing type 1 diabetes is a learnable skill — and that the right education can transform someone's relationship with their diabetes from one of constant uncertainty to one of informed confidence. Our vision is a T1D community where evidence-based, pedagogically sound education is available to everyone: in the clinic, at home, on a trail, and in every moment that diabetes demands a decision.
About the Simulators
The insulin models are based on published pharmacokinetic data from insulin manufacturers. Food absorption curves draw from research on carbohydrate, fat, and protein digestion rates. Exercise effects — including the acute glucose-lowering response, stress hormone spike in high-intensity effort, post-exercise glycogen resynthesis, and overnight insulin sensitivity — are drawn from peer-reviewed exercise physiology and diabetes literature.
All content is reviewed by people with lived experience with type 1 diabetes. No actual blood sugar values appear in the simulators — only relative effects — because every body is different and nothing here is prescriptive.
Organization
Beta Cell Foundation is a 501(c)(3) organization, which focuses on diabetes education and community building. All donations are tax-deductible to the extent permitted by law.
We do not collect any personal information from visitors to this site. Our servers temporarily log IP addresses as part of standard web infrastructure; this data is not stored, analyzed, or used to identify individual users. No user data is sold or shared with third parties.
The simulators run entirely in your browser. Nothing you enter — timing, doses, exercise details — is sent to any server.