What to eat before running: timing, portions, and gut comfort

Quick answer

What you should eat before running depends on how soon you will start, how long and hard the run will be, what you ate earlier, and what your stomach tolerates. With 2–4 hours available, use a familiar carbohydrate-centered meal and keep fat and fiber moderate if either causes symptoms. With 30–90 minutes available, shrink the portion and choose an easy-to-digest carbohydrate snack such as toast with jam, a banana, applesauce, a small bowl of cereal, or a rice cake. A short, easy run may not require a special snack when your daily intake is adequate; intervals, long runs, and races deserve a practiced fuel plan.

Do not search for one perfect food. Build a repeatable combination of amount + timing + tolerance. Test it before ordinary training, record hunger, fullness, nausea, cramping, bathroom urgency, energy, and run quality, then change one variable at a time. Never debut a large breakfast, concentrated drink, caffeine dose, or restrictive diet on race morning.

Key facts

• Run duration and intensity determine how valuable pre-run carbohydrate is likely to be.
• More digestion time permits a larger and more mixed meal.
• Fat, fiber, and large portions can delay stomach emptying and worsen symptoms in susceptible runners.
• Repeated practice trains both the runner’s routine and gastrointestinal tolerance.
• Daily energy availability supports health, recovery, and consistent training beyond one snack.

Start with the run, not a food list

A 25-minute conversational jog and a 2-hour progression run are not the same nutritional problem. The first may begin with adequate liver and muscle fuel from normal meals. The second can make carbohydrate availability, hydration, and in-run intake part of performance and safety. A hard 5K is short but intense; a gentle 10K may last longer while demanding less speed. Distance alone therefore cannot choose breakfast for you.

Ask five questions before opening the cupboard:

1. What is the session’s purpose? Easy movement, pace work, a long run, a race, or a fitness test?
2. How long will you actually be moving? Include warm-up, cooldown, delays, and travel when planning access to food and fluid.
3. When did you last eat? A run two hours after lunch differs from one immediately after an overnight fast.
4. What happens to your stomach at this intensity? Fast running, heat, anxiety, and jostling can all reduce tolerance.
5. What must happen afterward? A second session, demanding workday, pregnancy, diabetes management, or recovery from low energy availability can make underfueling more consequential.

Pre-exercise feeding improves prolonged aerobic performance more consistently than it improves short exercise, according to a systematic review and meta-analysis of 46 studies (Aird et al., 2018). That does not prove every runner needs breakfast before every jog. It supports a proportional rule: protect sessions whose duration, intensity, or purpose depends on sustained carbohydrate availability.

If you are still building a basic walk-run habit, the start-running-after-40 guide should set the progression; food cannot rescue a session that is too hard for your current capacity.

If your real question is whether intentionally running without breakfast improves fat loss or endurance, the fasted-running guide examines that separate claim. This article assumes you have chosen to eat and helps you make the meal fit the run.

Match the portion to the time available

Sports-nutrition guidance often gives a broad pre-event target of about 1–4 grams of carbohydrate per kilogram of body weight (0.45–1.8 g/lb) in the 1–4 hours before prolonged competition. The low end fits a shorter window or smaller need; the high end is an athlete-scale refueling strategy for long, demanding events, not a mandatory breakfast for a recreational 5K. World Athletics also recommends reducing fat, fiber, and protein according to the runner’s risk of gastrointestinal problems (World Athletics consensus statement).

Treat that range as a framework, not an arithmetic challenge. A 70 kg (154 lb) runner would obtain an enormous 280 g of carbohydrate at the upper edge. That may fit a specific long-race plan with four hours to digest, but it is inappropriate as a default. Training history, body size, normal diet, event demands, appetite, and tolerance decide where—or whether—you use the range.

Time before the run	Useful starting structure	Familiar examples	Main risk to avoid
3–4 hours	Normal meal, carbohydrate-centered, with moderate protein and personally tolerated fat and fiber	Oatmeal, banana, milk or soy drink, and toast; rice with eggs or tofu and cooked vegetables; cereal, yogurt, fruit, and a bagel	Turning a guideline into an oversized feast
2–3 hours	Smaller meal with less fat and roughage	Toast with jam plus yogurt and fruit; oatmeal with banana; rice or noodles with a small portion of lean protein	Heavy sauces, fried foods, or unfamiliar fiber
60–90 minutes	Compact snack dominated by easy carbohydrate	Banana and toast; small cereal bowl; applesauce and crackers; rice cakes with honey	Too much food for the remaining digestion time
15–45 minutes	Small, familiar top-up only when useful	A few bites of banana, applesauce pouch, a slice of white toast with jam, or a tolerated carbohydrate drink	Concentrated intake, new products, or drinking a large volume at once

These are patterns, not prescriptions. “Healthy” food can still be poorly timed. A large bean salad, high-bran cereal, fried breakfast, or nut-heavy smoothie may be nourishing in ordinary life yet uncomfortable immediately before fast running. Conversely, lower-fiber bread or cereal can be a purposeful short-term choice near a key session without defining the quality of the whole diet.

A practical plate 3–4 hours before

Use a familiar carbohydrate base, add a moderate protein portion, and include only as much fat and fiber as experience supports. The meal should leave you neither stuffed nor hungry at the start. Examples include oatmeal with banana and milk; rice with eggs and cooked vegetables; a bagel with yogurt and fruit; or noodles with tofu and a light sauce.

This is not the moment to maximize every nutrient. High-fat toppings, very large meat portions, piles of raw vegetables, and several high-fiber foods can make the meal slower and bulkier. Save variety for the rest of the day when a sensitive stomach needs a simpler pre-run plate.

A small snack 30–90 minutes before

As the start approaches, reduce volume and complexity. Choose one or two foods that you can chew, swallow, and digest comfortably. A banana is convenient, but it is not uniquely effective; toast and jam, applesauce, low-fiber cereal, crackers, rice cakes, or a tolerated dairy or plant yogurt can play the same practical role.

Liquid or semi-solid carbohydrate can help a runner who cannot face solid food early in the morning, but concentration and volume still matter. Test the drink in training. “Liquid” does not guarantee “gentle,” especially when a beverage is very sweet, contains sugar alcohols, combines several stimulants, or is consumed rapidly.

Choose carbohydrates for purpose, not moral value

Carbohydrate supports blood glucose and contributes to muscle fuel during running. Its value rises as intensity and duration rise because fast ATP production relies increasingly on carbohydrate. In a randomized crossover trial involving 21 trained and recreational men, a high-carbohydrate pre-event meal containing 3 g/kg extended time to exhaustion by about 8% compared with fasting and by about 7% compared with a low-carbohydrate meal; the small, male-only laboratory sample and exhaustion test limit how directly that result predicts a road race (Aandahl et al., 2021).

The lesson is not that more carbohydrate always makes a runner faster. It is that a demanding endurance test can expose a difference that a short easy run may not. Total intake over the previous day, glycogen status, the meal’s timing, and carbohydrate consumed during a long run all interact.

Glycemic index is not a race-morning ranking

Runners sometimes classify pre-run foods as “slow” or “fast” from glycemic index alone. A systematic review and meta-analysis did not find a clear endurance-performance advantage for low- versus high-glycemic-index pre-exercise meals (Burdon et al., 2017). Mixed meals, portion size, cooking, ripeness, individual glucose response, and subsequent carbohydrate intake all change the picture.

Choose by the complete task: sufficient carbohydrate, comfortable digestion, convenient timing, and a routine you can repeat. A food that looks ideal on a chart but causes urgency at mile two is not your ideal pre-run food.

Protein can be present without becoming the main fuel

A moderate amount of familiar protein may improve satiety and make the meal feel complete. Yogurt, milk or soy drink, eggs, tofu, or a modest portion of lean meat can fit when time permits. Large protein portions immediately before running do not substitute for carbohydrate in a pace-dependent session and may add bulk or slow digestion.

Protein matters across the whole day for adaptation and recovery. Keep the pre-run decision narrow: include enough to suit the meal and your appetite, but do not force a large dose when the start is close.

Fat and fiber are dose-and-timing questions

Fat and fiber support a healthy diet, but both can be difficult in a large meal close to hard running. The issue is not that either nutrient is “bad.” The issue is the combination of meal volume, digestion time, running intensity, personal tolerance, and bathroom access.

A runner who tolerates oatmeal, nut butter, and berries three hours before an easy long run does not need to abandon them. Another who develops cramping before races may temporarily reduce fiber and fat in the final meal while keeping an otherwise varied diet. Make targeted changes, not permanent food rules.

Use the session matrix

Planned run	Why pre-run food may matter	Practical starting decision
20–45 min easy run	Fuel demand is modest when daily intake is adequate	No special snack may be needed; eat if hungry, depleted, or medically advised
45–75 min steady run	Duration and pace begin to matter	Use the prior meal if recent, or add a small carbohydrate snack
Intervals, tempo, or hill repetitions	Quality depends on pace, concentration, and repeatability	Arrive fed; use a meal 2–4 hours before or a smaller tested snack closer to the start
75–120 min long run	Carbohydrate availability and in-run planning become important	Eat a carbohydrate-centered meal or snack and bring the fuel you plan to practise
Run longer than 2 hours	Pre-run and during-run strategies work as one system	Practise the full event plan, including timing, fluid access, and carbohydrate during the run
5K or 10K race	Shorter duration but high intensity and start-time constraints	Rehearse the same breakfast or snack before key workouts; do not eat marathon-sized portions
Half marathon, marathon, or ultra	Glycogen, liver fuel, gut tolerance, and logistics all matter	Use a trained race-specific plan with qualified support when needed

The running-interval workout guide can help you identify when pace quality is the purpose rather than treating every run as interchangeable. For very long events, the marathon-wall guide explains why pre-race food, in-race carbohydrate, pacing, heat, and durability must be planned together.

Solve the early-morning problem the night before

An early start creates a scheduling constraint, not a new physiology. You may have too little time or appetite for a full breakfast, while liver glycogen has fallen overnight. Three strategies can all be reasonable depending on the session:

1. Short easy run: eat adequately the previous day, drink according to thirst, and run without a special breakfast if you already tolerate that pattern and have no medical reason to eat.
2. Quality session with little time: use a small familiar carbohydrate snack or drink, then complete the planned breakfast afterward.
3. Long run or race rehearsal: wake earlier for a practised meal, or use a smaller pre-run intake plus a deliberate during-run plan.

Do not compensate with a huge late dinner that disrupts sleep. A normal carbohydrate-containing evening meal and, when useful, a familiar bedtime snack can reduce morning pressure. If you routinely wake ravenous, feel weak during easy runs, or overeat later, the better fix may be greater daily energy intake rather than a more elaborate alarm-clock strategy.

The carbohydrates-at-night guide explains why an evening carbohydrate serving is not automatically converted to body fat and how timing fits the full diet and next-day training.

Morning runners should test timing on low-consequence days. Move the same snack from 30 to 60 minutes before the run, or halve the portion while keeping the food constant. That experiment teaches more than switching food, timing, caffeine, and workout intensity at once.

Fit afternoon and evening runs into ordinary meals

For an afternoon run, breakfast and lunch are part of the fuel plan. A normal lunch 3–4 hours before may be enough; a small carbohydrate snack 60–90 minutes before can bridge a longer gap. Avoid “saving calories” all day and then expecting one granola bar to support intervals.

Before an evening run, keep lunch adequate and choose a mid-afternoon snack that will not collide with dinner. If reflux or fullness worsens when running late, reduce meal size, increase the interval, choose lower-fat foods, and finish hard exercise farther from bedtime when your schedule allows. The answer is not necessarily to skip food and arrive depleted.

Late caffeine can impair sleep in susceptible people even when it makes the session feel sharper. If you use coffee, keep the amount and timing familiar and judge the whole outcome: run quality plus anxiety, urgency, palpitations, and that night’s sleep. The evidence supports performance benefits from caffeine for many—but not all—people and also documents substantial individual variation (Guest et al., 2021).

Prevent stomach trouble with controlled experiments

Exercise-associated gastrointestinal symptoms have multiple causes. Intensity, heat, dehydration, reduced blood flow to the gut, mechanical jostling, anxiety, meal size, concentrated carbohydrate, fat, fiber, and individual conditions can interact. One symptom does not identify one guilty food.

Use this sequence:

1. Record the context. Food, amount, timing, fluid, caffeine, run intensity, heat, menstrual-cycle context when relevant, symptoms, and bathroom timing.
2. Repeat a tolerable baseline. Establish one breakfast or snack that usually works before changing it.
3. Change one variable. Reduce portion, move it earlier, lower fat or fiber, or change concentration—not all four.
4. Practise event intake. Long-run fueling should be trained at realistic pace and conditions.
5. Escalate persistent problems. Recurrent diarrhea, vomiting, severe pain, blood, black stool, unexplained weight loss, anemia, or symptoms outside exercise need clinical evaluation.

Systematic reviews find that gut training and selected short-term dietary changes may reduce symptoms, but studies are heterogeneous and individualized practice remains central (Mlinaric and Mohorko, 2025; King et al., 2023). A low-FODMAP strategy is not a universal runner diet. It can be restrictive and is best used for a defined problem with a sports dietitian or gastrointestinal clinician, followed by reintroduction rather than indefinite avoidance.

Common symptom patterns and the first variable to test

Pattern	First low-risk experiment	Do not assume
Sloshing or heaviness	Reduce fluid and food volume immediately before the run; move the main intake earlier	That hydration requires forcing a large bottle at the start
Reflux or burping	Increase the meal-to-run interval and reduce high-fat or personally triggering foods	That all carbohydrate is the cause
Cramping or urgency	Repeat a lower-fiber, familiar meal before a comparable run	That gluten or dairy must be removed permanently
Nausea during hard work	Test a smaller pre-run portion and practise at lower intensity first	That the same plan will work in heat or race anxiety
Hunger before the start	Add a small carbohydrate top-up or make the earlier meal more substantial	That hunger proves glycogen is empty
Energy crash late in a long run	Review the full-day, pre-run, and during-run plan	That breakfast alone can cover every long session

Hydrate early without chasing clear urine

Begin the run normally hydrated rather than trying to repair the entire day in the final 15 minutes. The American College of Sports Medicine recommends starting prehydration several hours before exercise so fluid can be absorbed and excess can be excreted, while emphasizing individualized plans because sweat rates vary widely (ACSM fluid replacement position stand).

Use ordinary meals, thirst, urine pattern, weather, session duration, and personal sweat history together. A modest drink with the pre-run meal may be enough for a short cool run. Heat, humidity, altitude, a long session, heavy sweating, and limited access to fluid require more planning. Excessive drinking can also be dangerous; finishing heavier because you forced fluid is not a hydration victory.

The exercise hydration guide explains how to estimate sweat loss, decide when sodium helps, and avoid both dehydration and overdrinking. Practise carrying or accessing fluid before a long event rather than discovering at race pace that a bottle, cup, or concentrated drink upsets your stomach.

Build a seven-run personal fueling test

This is a decision framework, not a diet plan. Use comparable training sessions and stop any experiment that causes concerning symptoms.

Run	Keep constant	Variable to test	What to record
1	Familiar easy route and pace	Current usual routine	Hunger, fullness, GI symptoms, energy, perceived effort
2	Same food and session	Eat 30–45 minutes earlier	Start comfort and first-half symptoms
3	Same timing and session	Slightly smaller portion	Hunger versus heaviness
4	Same portion and timing	Lower-fiber version	Cramping, urgency, stool pattern
5	Familiar harder workout	Use the best tolerated snack	Pace quality and repeatability
6	Familiar long run	Add the planned during-run intake	Late-run energy and gut response
7	Race rehearsal	Repeat the complete best plan	Logistics, bathroom timing, confidence, recovery

Do not optimize by feeling alone. A meal can feel light yet leave a runner underfueled later; another can feel pleasantly filling but impair early pace. Compare the planned workout with what happened. The best routine supports the intended effort and leaves digestion unremarkable.

See pre-run food inside the whole training week

One breakfast cannot correct chronic underfueling. Low energy availability means dietary intake is insufficient relative to exercise demands after accounting for the energy needed for health and normal physiology. It can affect athletes of every gender and contribute to impaired bone, hormonal, immune, metabolic, cardiovascular, psychological, and performance outcomes. The 2023 International Olympic Committee consensus emphasizes that the pattern is complex and individualized rather than diagnosable from one skipped snack (Mountjoy et al., 2023).

SuperAge can help you view workouts alongside available Apple Health trends such as sleep, resting heart rate, HRV, and cardio fitness. Add your own note about the meal, timing, hunger, or symptoms, then look for repeatable patterns across weeks. A watch or app cannot measure glycogen, diagnose RED-S, prescribe carbohydrate, or determine whether gastrointestinal symptoms are benign.

Use the wider pattern to ask better questions: Are pace sessions deteriorating? Is recovery extending? Is sleep worsening after late caffeine? Are easy runs becoming compulsive compensation for food? Is menstrual function changing, libido falling, illness recurring, or bone pain appearing? Those are reasons to step back and seek qualified medical or sports-dietetic support—not reasons to make the pre-run meal smaller.

The recovery-debt guide can help separate a single poor run from a worsening multi-day cluster of training, sleep, mood, and recovery signals.

Make one repeatable pre-run card

Write one card for each session type you perform regularly:

SESSION: 60-minute interval workout at 7:00 AM
DINNER: familiar carbohydrate-containing meal, ordinary portion
WAKE: 5:45 AM
FOOD: tested small carbohydrate snack
FLUID: drink to thirst; no forced bolus
CAFFEINE: usual amount only, or none
BACKUP: fast-acting carbohydrate available
STOP/ADJUST: dizziness, confusion, escalating nausea, chest pain, or unusual weakness
AFTER: normal breakfast with carbohydrate, protein, and fluid

The card removes race-morning improvisation. It also makes cause and effect visible: if the routine fails, you can alter one line instead of blaming an entire food category.

Review your run-and-recovery pattern with SuperAge

Use SuperAge to place the run beside sleep, heart-rate, HRV, and fitness trends available from Apple Health, then add the context the sensors cannot know: what you ate, when you ate, and how your gut felt. Review several comparable sessions before drawing a conclusion.

Safety exceptions need individual plans

Generic pre-run advice does not replace clinical care. Seek individualized guidance when you use insulin or insulin-secretagogue medication, are pregnant, are under 18, have a current or past eating disorder, have undergone bariatric surgery, have recurrent fainting or hypoglycemia, have diagnosed gastrointestinal disease, or show signs of low energy availability.

For people using insulin or medications that can cause hypoglycemia, exercise timing, active insulin, starting glucose, carbohydrate, and the delayed effect of activity interact. The American Diabetes Association advises individualized medication and carbohydrate strategies; do not change insulin from a blog article (ADA Standards of Care 2026). Carry the glucose treatment and monitoring tools specified in your care plan.

Stop running and move to a safe place for confusion, faintness, shaking, loss of coordination, chest pain, severe or unusual breathlessness, persistent vomiting, or weakness that alters gait. Blood in vomit or stool, black stool, severe abdominal pain, or symptoms that persist outside exercise require prompt medical assessment.

Common pre-run eating mistakes

1. Eating by distance alone. A hard 5K and an easy 5K impose different demands.
2. Using the maximum carbohydrate guideline as a target. The broad range covers very different athletes, events, and timing windows.
3. Trying to make breakfast nutritionally perfect. A simpler meal can be appropriate near hard exercise.
4. Adding food without adding digestion time. Portion and timing must change together.
5. Copying an elite athlete’s meal. Body size, pace, gut training, race duration, and professional support differ.
6. Changing everything on race week. New foods, caffeine, gels, and fiber changes make failures impossible to interpret.
7. Treating GI symptoms as weakness. Repeated symptoms deserve structured testing and, when persistent or severe, clinical care.
8. Ignoring the rest of the day. Chronic low intake cannot be repaired by one banana five minutes before training.

Key takeaways

• Match pre-run food to session purpose, duration, intensity, time since the last meal, and personal tolerance.
• With 2–4 hours, use a familiar carbohydrate-centered meal; with less time, reduce portion and complexity.
• Short easy runs may not need special fuel, while intervals, long runs, and races deserve a practiced plan.
• Use the 1–4 g/kg (0.45–1.8 g/lb) pre-event carbohydrate range as context, not a universal target.
• Reduce fat, fiber, and meal size only as much as your timing and gastrointestinal history require.
• Practise the complete plan—including during-run fuel and fluid—before important sessions or races.
• Review daily energy availability and recovery rather than judging health from one breakfast.
• Seek individualized care for diabetes medication, RED-S risk, pregnancy, eating-disorder history, or persistent gastrointestinal symptoms.

FAQ

Should I eat before every run?

No. A short easy run may not require a special snack when you have eaten adequately and tolerate the timing. Eat before sessions whose duration, intensity, or purpose benefits from carbohydrate, and whenever hunger, medical needs, prior underfueling, or your own response says that food is useful.

How long before running should I eat?

Allow about 2–4 hours for a normal meal and 30–90 minutes for a smaller snack as practical starting windows. Larger, fattier, higher-fiber meals usually need more time. Your tested tolerance matters more than a perfect clock time.

Is a banana enough before a run?

A banana may be enough as a small top-up before a short or moderate session, but it is not a complete plan for every runner or long run. The prior day’s intake, last meal, body size, session duration, intensity, and during-run fuel determine whether more is needed.

What should I eat before a 5K?

Use the same familiar meal or snack that worked before a hard workout. A 5K does not require a marathon-sized breakfast, but its intensity can make arriving hungry or depleted unhelpful. Match the portion to the time available and rehearse it before race day.

What should I eat before an early-morning run?

For a short easy run, no special food may be necessary if daily intake is adequate and you tolerate the routine. Before intervals, a long run, or a race, use a small easy carbohydrate snack when time is short or wake earlier for a practised meal.

Are eggs good before running?

Eggs can provide protein in a meal several hours before running, but they contribute little carbohydrate and may feel heavy when combined with a large, fatty breakfast. Pair a tolerated portion with carbohydrate and allow enough digestion time.

Can I drink coffee before running?

Yes, if coffee is already familiar and does not trigger anxiety, reflux, urgency, palpitations, or poor sleep. Do not introduce or sharply increase caffeine on race day. Judge the response across both the run and later recovery.

What if eating before running always upsets my stomach?

Begin with a smaller, lower-fiber familiar snack, move it earlier, and change one variable at a time. Record the workout intensity, heat, fluid, caffeine, and symptoms too. Persistent, severe, bloody, or non-exercise symptoms need assessment by a clinician or sports dietitian.

References

1. Thomas DT, Erdman KA, Burke LM. Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: nutrition and athletic performance. Journal of the Academy of Nutrition and Dietetics. 2016;116(3):501–528.
2. Burke LM, Castell LM, Casa DJ, et al. International Association of Athletics Federations consensus statement 2019: nutrition for athletics. International Journal of Sport Nutrition and Exercise Metabolism. 2019;29(2):73–84.
3. Aird TP, Davies RW, Carson BP. Effects of fasted vs fed-state exercise on performance and post-exercise metabolism: a systematic review and meta-analysis. Scandinavian Journal of Medicine & Science in Sports. 2018;28(5):1476–1493.
4. Aandahl HA, Noordhof DA, Tjønna AE, Sandbakk Ø. Effect of carbohydrate content in a pre-event meal on endurance performance-determining factors. Frontiers in Sports and Active Living. 2021;3:664270.
5. Burdon CA, Spronk I, Cheng HL, O’Connor HT. Effect of glycemic index of a pre-exercise meal on endurance exercise performance. Sports Medicine. 2017;47(6):1087–1101.
6. Sawka MN, Burke LM, Eichner ER, Maughan RJ, Montain SJ, Stachenfeld NS. American College of Sports Medicine position stand: exercise and fluid replacement. Medicine & Science in Sports & Exercise. 2007;39(2):377–390.
7. Mlinaric J, Mohorko N. Nutritional strategies for minimizing gastrointestinal symptoms during endurance exercise. Journal of the International Society of Sports Nutrition. 2025;22(1):2529910.
8. King AJ, O’Donnell C, Stellingwerff T, Poon ETC, Tee N, Burke LM. The effect of gut-training and feeding-challenge on markers of gastrointestinal status in response to endurance exercise. Sports Medicine. 2023;53(7):1449–1470.
9. Guest NS, VanDusseldorp TA, Nelson MT, et al. International Society of Sports Nutrition position stand: caffeine and exercise performance. Journal of the International Society of Sports Nutrition. 2021;18(1):1.
10. Mountjoy M, Ackerman KE, Bailey DM, et al. 2023 International Olympic Committee consensus statement on Relative Energy Deficiency in Sport. British Journal of Sports Medicine. 2023;57(17):1073–1097.
11. American Diabetes Association Professional Practice Committee. Facilitating positive health behaviors and well-being to improve health outcomes: Standards of Care in Diabetes—2026. Diabetes Care. 2026;49(Suppl 1):S89–S131.