The 60% Rule: Pacing Exercise Through Cancer Fatigue

Cancer-related fatigue doesn’t just take your energy, it takes your trust in your own body. In this video, I walk through the 60% Rule, a simple way to pace activity through cancer treatment and recovery, so a good day doesn’t turn into a crash the next one.

Before you decide how much to do today, check the weather. Every day sits somewhere on a simple traffic light: green, amber, or red. On a green day, symptoms are stable and energy is relatively good. On an amber day, sleep was poor, treatment is biting, or fatigue is already building. On a red day, your body needs rest, not effort, and that’s not a failed day, that’s the correct call.

Once you know today’s colour, you know today’s 100%, what your body can realistically manage right now. Not what it could do before diagnosis, not what a fitness tracker suggests, not what anyone else seems to be managing.

Then comes the 60% Rule: use roughly 60% of today’s 100%, whatever colour day it turns out to be, and leave a deliberate reserve. The goal isn’t to prove what you can survive today, it’s to build what you can repeat tomorrow.

Watch the full talk above for the traffic-light check, the five levers of recovery, and how to break the boom-and-bust cycle for good.

Full Transcript

Understanding Cancer-Related Fatigue

One of the easiest mistakes to make during cancer recovery begins with four words: “I feel good today.” Because a good day feels like an invitation to catch up with your old life. So you go for the walk. You answer the emails. You clean the kitchen. You do the shopping. You finally see the friend you’ve been cancelling on. And for a few hours, it feels wonderful. It feels normal. Then tomorrow sends you the bill.

You wake up flattened. Your limbs feel heavy. Your brain feels foggy. The smallest task feels enormous. And because you felt all right yesterday, the crash makes no sense. So you blame yourself. You think, “I must be weak. I must be lazy. I must be doing recovery wrong.” But you are not weak, and you are not lazy. You have simply spent Tuesday’s energy on Monday.

Cancer-related fatigue does not only steal energy. It steals trust. You stop knowing what your body can do, what it will cost, or whether a good day is real or just another ambush.

I am Dave Poole. I now work as a cancer exercise specialist, and I see the same pattern again and again. I call it the boom-and-bust cycle. One woman I work with, I’ll call her Helen, put the whole problem into one question: “How can I exercise to build strength when the fatigue keeps hitting me?” That is the paradox. Movement can help, but the wrong dose can make tomorrow harder.

Recovery is not about using everything you have. It is about leaving enough to come back tomorrow.

There is no way I can hand you everything you need to navigate fatigue through cancer treatment in one video. What I can do is give you the framework I use with clients every single day, and show you how it played out for real people going through exactly what you’re going through.

The Boom-Bust Cycle of Recovery

On a better day, you boom. You try to make up for the days cancer has taken from you. You do everything while you can. Then you bust. You may lose the rest of that day, the next day, or several days. This is not a motivation problem. It is a dosage problem.

Another client, Marion, described exactly how the cycle catches you: “I overdid it because it feels relatively easy at the time.” That is the trap. The cost does not always arrive while you are doing the activity. It arrives later.

One of my clients, I’ll call her Priya, wrote to me two weeks after surgery. Before her diagnosis, she had been deadlifting 45 kilograms. Now she wrote: “Psychologically it is tough to go from deadlifting 45kg to nothing more than 4kg.” Her final line was: “I know that this is only a chapter in my book of life, but it still sucks.” Pacing is not just a physical adjustment. It can feel like grief. You are not only lowering a weight, you are renegotiating your identity.

Priya’s old 100% was no longer her current 100%. And that is the mistake most of us make, we measure today’s body against yesterday’s capacity. But today’s 100% is not yesterday’s 100%.

The 60% Rule is simple: first, work out what 100% looks like today. Then aim to use roughly 60% of that, leaving a deliberate reserve. Not 60% of what you could do before cancer, not what your watch says, not what somebody on Instagram is doing. Sixty per cent of today. It is not about doing less forever. It is about doing an amount you can recover from, learn from, and repeat.

Before an activity, ask three things: what is your energy like right now, honestly? What else must your body do today? And how do you want to feel one hour after you finish, and tomorrow morning? That third question changes everything.

Capacity changes, so the plan has to change with it. On a green day, symptoms are stable and energy is relatively good. On an amber day, sleep was poor, treatment is biting, or fatigue is building, so you shrink the dose. On a red day, your body is telling you to stop, and rest is the correct dose, not a failed workout.

The Five Levers of Recovery

Before I worked in cancer exercise, I spent more than two decades working in sound. Recovery reminds me of a mixing desk. A good mix isn’t created by pushing every channel to maximum, do that and everything distorts. Recovery has five dials: movement, pacing, sleep, nutrition, and stress. You do not have to fix all five today. Choose the one adjustment that makes tomorrow more possible.

The hardest part is often not physical, it’s the voice in your head comparing you to the person you used to be. So fire the critic and hire a coach. When that voice says, “you should be doing more,” ask instead, “what does my body actually need today?” Restraint can be a form of strength.

A cancer diagnosis takes control of so much. The 60% Rule can’t give all of that back, but it can give you a way to make one decision differently. I think of Eleanor, one of my clients, who came to me struggling to get in and out of the bath. Over time, she began walking more, then lifting weights, not by attacking every good day, but by building an amount she could repeat. Eventually she was walking 7,000 to 8,000 steps a day and strength training three times a week. After one session, she said five words: “I feel fitter and stronger.” What I heard was more than fitness. I heard trust returning.

So the next time you have a good day, don’t ask, “how much can I squeeze out of it?” Ask, “what can I do today that still leaves me a tomorrow?” Find today’s 100. Use 60. Protect tomorrow.

A Safety Note

Get medical guidance before starting or progressing exercise if you have known bone metastases, a fever or active infection, marked or unstable breathlessness, chest pain, symptoms of severe anaemia, recent surgery without clearance, uncontrolled or unexplained pain, new or sudden swelling, or dizziness or fainting. These are not reasons to give up on movement. They are reasons to get the right guidance first.