Eating enough to climb: energy availability and RED-S

Climbing has a complicated relationship with body weight. Because we move our own body up the wall, it is easy to assume that lighter is always better. That idea has caused real harm. Under-fuelling does not make climbers stronger in the long run; it makes them more likely to get injured, ill and stuck.

This post is general information. If you are worried about your eating, energy or health, or someone else's, please talk to a doctor, a registered dietitian or sports dietitian, or another qualified professional.

What is energy availability?

Energy availability is, roughly, the energy left over for the body's essential functions after the energy cost of exercise is accounted for. Those functions include hormone production, bone maintenance, immunity, digestion, tissue repair and keeping you warm.

When you eat less than you need for training and daily life, energy availability falls. In the short term you may feel fine. Over time, the body adapts by turning down systems it considers non-essential.

RED-S: the consensus view

The International Olympic Committee (IOC) published a consensus statement in 2014 introducing the term relative energy deficiency in sport (RED-S), updated it in 2018, and published a further update in 2023. The key idea is that low energy availability, especially when it is problematic and prolonged, can affect many body systems and aspects of performance, not just one.

The earlier concept of the "female athlete triad" focused on women: low energy availability, menstrual dysfunction and low bone density. RED-S broadened the picture and made clear that it affects athletes of all genders. Men can experience lowered testosterone, reduced bone density and the same performance problems.

Low energy availability is not always deliberate. Some climbers simply do not realise how much they need, have busy days with little time to eat, or increase training without eating more.

Signs to watch for

RED-S can show up in many ways. Possible signs include:

• Persistent fatigue, or training feeling much harder than it should.
• Frequent illness or slow recovery.
• Stress fractures or injuries that keep coming back.
• Irregular or absent periods. Missing periods are a medical signal, not a normal side effect of training, and a reason to see a doctor.
• Low libido or, in men, signs of low testosterone.
• Feeling cold, dizziness, or poor concentration.
• Mood changes, irritability or anxiety around food.
• Stalled or declining performance despite consistent training.

None of these signs alone means someone has RED-S, and many have other causes. Only a qualified professional can assess this properly. The point is not to self-diagnose but to know when to ask for help.

If you are training hard and feeling worse, under-fuelling is one of the first things worth ruling out.

Fuelling for climbing

Rather than thinking about weight, think about fuelling the work:

• Eat regular meals, and do not skip meals on training days.
• Include carbohydrates around harder sessions. They are the main fuel for high-intensity efforts.
• Get enough protein spread across the day to support repair and adaptation.
• Eat more when you train more. A bigger training week or a climbing trip needs more food, not the same amount.
• Bring snacks to long sessions and outdoor days.
• Drink enough. See hydration for climbers.

For coaches and clubs

Coaches have a big influence on how athletes think about their bodies. Avoid comments about weight or appearance. Do not weigh athletes or set weight targets; leave nutrition questions that go beyond general advice to qualified professionals. Praise strength, skill and effort, and make it normal to talk about eating enough. Young athletes are particularly vulnerable to messages about body size; see youth climbing and long-term development.

In Train Climb

• Log effort and how you felt for every session. A run of sessions that feel harder than usual is worth noticing.
• Use the morning check-in. Persistent fatigue, poor sleep and soreness feed into the injury-risk light and can be early signs that something is off.
• Note recurring illness or injury in your session notes and talk to your coach through messages.
• Plan recovery. See proper rest and recovery and deload weeks.
• Read also: women in climbing and the menstrual cycle.