Each sign below has many possible causes, so none of them says much on its own. Here's why sports doctors pay attention to each one.
You didn't tap any of the signs on this list. Here's the list anyway, plus a few habits runners use around their training.
Runs feeling harder, or slow to recover
The IOC's 2023 statement lists slower endurance performance, a weaker response to training, and not recovering between sessions among the effects of running low on energy. A hard block, stress, heat, poor sleep, or being sick can do this too.
IOC 2023
Mountjoy M, Ackerman KE, Bailey DM, et al. 2023 International Olympic Committee's (IOC) consensus statement on Relative Energy Deficiency in Sport (REDs). Br J Sports Med 2023;57(17):1073-1097. doi:10.1136/bjsports-2023-106994
Sleep
Sleep trouble is on the IOC statement's list of emerging signs, which means researchers are still studying the link. Stress, pain, and a new schedule are common causes too.
IOC 2023
Mountjoy M, Ackerman KE, Bailey DM, et al. 2023 International Olympic Committee's (IOC) consensus statement on Relative Energy Deficiency in Sport (REDs). Br J Sports Med 2023;57(17):1073-1097. doi:10.1136/bjsports-2023-106994
Getting sick more often
The IOC statement lists getting sick more often among the health effects of low energy in athletes. Heavy training blocks and busy seasons at work or home can play a part too.
IOC 2023
Mountjoy M, Ackerman KE, Bailey DM, et al. 2023 International Olympic Committee's (IOC) consensus statement on Relative Energy Deficiency in Sport (REDs). Br J Sports Med 2023;57(17):1073-1097. doi:10.1136/bjsports-2023-106994
Stomach trouble
The IOC statement lists stomach and gut trouble, during exercise and on regular days, as an emerging sign that researchers are still learning about. It has many other causes, from certain foods to race-day nerves.
IOC 2023
Mountjoy M, Ackerman KE, Bailey DM, et al. 2023 International Olympic Committee's (IOC) consensus statement on Relative Energy Deficiency in Sport (REDs). Br J Sports Med 2023;57(17):1073-1097. doi:10.1136/bjsports-2023-106994
Mood and drive
The IOC statement lists more stress, worry, and mood changes among its emerging signs, and lower drive to train among the effects on performance. Life stress causes all of these too. If your mood has been low for a while, it's worth talking to a doctor or someone you trust.
IOC 2023
Mountjoy M, Ackerman KE, Bailey DM, et al. 2023 International Olympic Committee's (IOC) consensus statement on Relative Energy Deficiency in Sport (REDs). Br J Sports Med 2023;57(17):1073-1097. doi:10.1136/bjsports-2023-106994
Periods stopping or spacing out
First: if there's any chance of pregnancy, a pregnancy test is the place to start.
The IOC statement lists missed periods, and periods that come far apart, among the signs sports doctors look at. Many other things can cause this, like thyroid changes, PCOS, or perimenopause, and a doctor can check for them. It's worth bringing up at your next visit.
IOC 2023
Mountjoy M, Ackerman KE, Bailey DM, et al. 2023 International Olympic Committee's (IOC) consensus statement on Relative Energy Deficiency in Sport (REDs). Br J Sports Med 2023;57(17):1073-1097. doi:10.1136/bjsports-2023-106994
On hormonal birth control
Hormonal birth control can change or stop bleeds, so period changes can't be read the usual way while you're using it. The IOC statement makes the same point.
IOC 2023
Mountjoy M, Ackerman KE, Bailey DM, et al. 2023 International Olympic Committee's (IOC) consensus statement on Relative Energy Deficiency in Sport (REDs). Br J Sports Med 2023;57(17):1073-1097. doi:10.1136/bjsports-2023-106994
Pregnant or recently had a baby
We left the questions out of your results. Tiredness, sleep changes, stomach trouble, and mood changes are all common during pregnancy and after a baby, so this list doesn't fit this time well. Your OB or midwife is the best person for questions about eating and running right now.
IOC 2023
Mountjoy M, Ackerman KE, Bailey DM, et al. 2023 International Olympic Committee's (IOC) consensus statement on Relative Energy Deficiency in Sport (REDs). Br J Sports Med 2023;57(17):1073-1097. doi:10.1136/bjsports-2023-106994
After menopause
Periods don't apply as a sign after menopause, so we left that question out. Most of the research behind this list was done in younger athletes, so the other cards may fit less neatly. A sports medicine doctor can help sort that out.
IOC 2023
Mountjoy M, Ackerman KE, Bailey DM, et al. 2023 International Olympic Committee's (IOC) consensus statement on Relative Energy Deficiency in Sport (REDs). Br J Sports Med 2023;57(17):1073-1097. doi:10.1136/bjsports-2023-106994
Bone stress injury
The IOC statement lists bone stress injuries in the past two years among the signs sports doctors look at. Bone health depends partly on getting enough energy. Mileage, shoes, and running form matter too, so a sports medicine doctor can look at the whole picture.
IOC 2023
Mountjoy M, Ackerman KE, Bailey DM, et al. 2023 International Olympic Committee's (IOC) consensus statement on Relative Energy Deficiency in Sport (REDs). Br J Sports Med 2023;57(17):1073-1097. doi:10.1136/bjsports-2023-106994
Running without eating first
Plenty of runners head out without eating, especially early in the morning. If you'd like to try something first, small and simple works: a banana, toast with honey, or a glass of juice. What sits well is personal, so try a few on easy days.
Read more: 12 things to eat before a run
Nothing on long runs
Many runs don't need any food. Long ones are different, and that's when something in your pocket starts to matter. Dates, raisins, and salted boiled potatoes all work, and gels aren't required. Try them on training runs first, never for the first time on race day.
Read more: What to eat before, during and after a long run
Busy days
Busy days are when meals slip. A snack you already keep in your bag or desk drawer can fill a long gap, including one before an evening run.
Read more: 11 things from the snack drawer
Eat around your runs. Something small before, if it sits well, and a full meal after.
Bigger days, more food. A long run or a hard workout asks for more food that day. Rest days still need regular meals.
Know the list. Runs feeling harder, slow recovery, poor sleep, more colds, stomach trouble, mood changes, period changes, and bone stress injuries.
Source: IOC 2023 consensus statement (full line in footnote)
Who to talk to
A sports medicine doctor or a sports dietitian (look for the CSSD credential) can look at the whole picture, including other causes.
If any of these signs show up later, a sports medicine doctor or a sports dietitian (CSSD) is a good person to raise them with.
Your OB or midwife is the right first stop.
Find a dietitian near you
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What sits well is personal. Try things on easy days, and never try something new on race day.
Before: when you're already at the door
- Juice
- A spoonful of jam or honey
- A sports drink
Before: when there's a bit more room
- A banana
- White toast or a bagel with jam or honey
- Plain rice cakes
- Plain crackers or pretzels
- Applesauce
- A cereal bar or fig bar
Before: afternoon runs
- A second small lunch
- Whatever's already in your bag: a toaster pastry, animal crackers, a granola bar
During: pocket food for long runs
- Dates
- Raisins
- Small boiled potatoes with salt
- Orange slices
- Short, cool runs: water is plenty. Long, hot, or very sweaty runs change that.
After: the longest list, on purpose
- Milk (chocolate counts)
- Eggs on toast
- Greek yogurt with fruit
- Salmon and rice
- A big pasta dinner
- Pretzels and water
- A big day asks for a bigger day of eating.
Want to see your own patterns? Idunia is a meal log built for women who run.