Train With Your Energy: Managing Cancer-Related Fatigue Around Exercise

Cancer-related fatigue is not the same as everyday tiredness.

It isn’t fixed by a nap. It doesn’t always improve with rest. And it doesn’t behave predictably.

That’s why this month we’re focusing on learning how to exercise with your energy — not against it.

The goal isn’t to do less. It’s to train in a way that supports long-term recovery.

Understanding Fatigue

Cancer-related fatigue is influenced by:

• Treatment history

• Inflammation

• Hormonal shifts

• Nervous system stress

• Sleep disruption

• Emotional load

It is both physical and neurological.(1)

That means pushing harder isn’t always the answer. But avoiding movement altogether isn’t helpful either.

Research consistently shows that appropriately dosed resistance training can improve fatigue over time.(2,3) The key word is appropriately.

The Boom-and-Bust Cycle

Many people experience this pattern:

Good day → train very hard → feel wiped out → skip sessions → feel frustrated → start again hard.

This “boom-and-bust” cycle doesn’t build strength. It drains confidence.

The solution isn’t to avoid effort. It’s to regulate it.

Why Effort Awareness Matters

This month, we’re introducing RPE — Rate of Perceived Exertion.

RPE is simply a way of rating how hard something feels on a scale of 1–10.

Instead of asking: “How much weight should I lift?”

We start asking: “How hard should this feel today?”

For most of March, we’ll aim to work at 6–7 out of 10.

That level:

• Stimulates strength gains

• Protects recovery

• Reduces nervous system overload

• Makes training repeatable

You should leave sessions feeling like you could have done a little more.

That’s not undertraining. That’s intelligent training.

How to Use RPE in Real Life

Before you start a day or exercise session, ask:

• How did I sleep?

• How do I feel physically?

• How do I feel mentally?

If energy is low, you might stay closer to 5–6/10.

If energy is good, you might move toward 7/10.

The weight you lift doesn’t define the success of the session. The consistency does.

Strength Without Burnout

Building strength without burnout means:

• Leaving 1–3 reps “in reserve”

• Avoiding grinding, breath-holding reps

• Maintaining smooth, controlled tempo

• Finishing sessions feeling steady rather than depleted

Over weeks and months, that approach builds far more sustainable progress than occasional maximal effort.

How Each Level Should Feel

You can use this scale during classes or recordings.

1–2 / 10 : Very light effort

Warm-up pace. Could continue for a long time. Breathing unchanged.

3–4 / 10: Light effort

Comfortable. You’re working, but conversation is easy.

5 / 10: Moderate effort

You feel purposeful. Breathing slightly elevated. Could continue comfortably.

6 / 10: Challenging but controlled

You could perform 3–4 more reps. Breathing elevated but steady. No strain.

7 / 10: Strong working effort

You could perform 2–3 more reps. Focus required. Still controlled.

8 / 10: Hard effort

Only 1–2 reps left in reserve. Breathing heavy. Technique may start to feel challenged.

9 / 10: Very hard

Almost maximal. Only 1 rep possible. Recovery required.

10 / 10: Maximal effort

No reps left. Not sustainable for fatigue management.

Where We’re Working This Month

For March, most sessions = 6–7/10

Because long-term recovery is built on repeatable effort — not occasional exhaustion.

The Takeaway

Fatigue doesn’t mean stop; it means adjust.

The skill we’re building this month is knowing the difference.

Strength improves when effort is consistent.

Recovery improves when stress is managed.

Train with your energy — and let consistency do the rest.

References:

1. Bower, J. E. (2014). Cancer-related fatigue—mechanisms, risk factors, and treatments. Nature Reviews Clinical Oncology.

2. Campbell, K. L., et al. (2019). Exercise Guidelines for Cancer Survivors: Consensus Statement from the International Multidisciplinary Roundtable. Medicine & Science in Sports & Exercise. https://doi.org/10.1249/MSS.0000000000002116

3. Comparison of Pharmaceutical, Psychological, and Exercise Treatments for Cancer-Related Fatigue. JAMA Oncology. https://doi.org/10.1001/jamaoncol.2016.6914