Key messages
- Resistance training during cancer therapy has the potential to improve fatigue and quality of life.
- Resistance training after cancer therapy may improve quality of life a little.
- More research could help understand the effects of resistance training before cancer therapy.
What is cancer-related fatigue?
Cancer-related fatigue is a feeling of extreme tiredness that lasts for a long time. It can come from cancer or cancer therapy, or both. Cancer-related fatigue affects both the body and mood, and makes it hard to perform regular activities. It is stronger than just being tired, and does not go away by resting.
What is resistance training, and how can it help?
Resistance training is a type of exercise where your muscles work against a force, for example, dumbbells, machines, resistance bands, or your own body weight. Resistance training affects many things that are linked to cancer-related fatigue. For example, it can make your muscles stronger, prevent muscle loss, and improve your mood, sleep, and fitness. Therefore, resistance training may help improve cancer-related fatigue.
What did we want to find out?
We wanted to find out if resistance training improves cancer-related fatigue. We looked at whether any positive effects on fatigue lasted after the end of training, measured in the short term (up to 12 weeks), medium term (over 12 weeks to under 6 months), and long term (6 months or longer). We also looked at quality of life, unwanted or harmful effects, depression, and anxiety.
What did we do?
We searched for studies that compared resistance training with no training in people diagnosed with any cancer. People could do any kind of resistance training, starting before, during or after cancer therapy. We summarised the results of the studies. We looked at aspects such as study methods and study size to rate our confidence in the evidence.
What did we find?
We found 21 studies with 2221 participants with different cancers. Resistance training started during cancer therapy in 14 studies, and after cancer therapy in seven studies. We found no studies on resistance training that started before cancer therapy. Most studies reported results on short-term effects.
Resistance training compared with no training during cancer therapy
- Twelve studies provided evidence about resistance training for fatigue in the short term, and it probably has a beneficial effect compared with no training. We are not sure about its effects in the medium or long term.
- Twelve studies provided evidence about resistance training for quality of life in the short term, and it may have a small beneficial effect compared with no training. We are not sure about its effects in the medium or long term.
- Only two studies reported unwanted or harmful effects for both people doing resistance training as well as those not doing training, and we are not sure about the effect of resistance training on unwanted or harmful effects.
Resistance training compared with no training after cancer therapy
- Three studies provided evidence about the effects of resistance training on fatigue in the short term, but we are unsure about its effects.
- Four studies provided evidence about the effects of resistance training on quality of life in the short term, and we found resistance training may have both a small beneficial effect or no effect on quality of life.
- No studies reported data on the effects of resistance training on either fatigue or quality of life in the medium or long term.
- Only three studies reported unwanted or harmful effects for both people doing resistance training as well as those not doing training, and we are not sure about the effect of resistance training on unwanted or harmful effects.
What are the limitations of the evidence?
Overall, our confidence in the evidence was low. People in the studies knew if they were doing resistance training or not. Although this was inevitable, it could have influenced the results. We did not find enough large studies that provided evidence for medium- and long-term effects of resistance training to be certain about our results. The way studies reported unwanted or harmful effects did not let us draw conclusions about the impact of resistance training on these effects.
How up to date is this evidence?
The evidence is up to date to October 2023.
Our review demonstrates beneficial effects of resistance training during anticancer therapy compared with no training on short-term CRF and QoL for people with cancer. Resistance training after anticancer therapy may also have a small beneficial effect on short-term QoL. Data on medium-, and long-term effects are sparse.
In order to facilitate evidence syntheses beyond a narrative report of the data, investigators of resistance training programmes should report adverse events more consistently and completely for all study arms, including control groups.
Cancer-related fatigue (CRF) is one of the most common symptoms associated with cancer and its treatment. Different types of exercise have demonstrated beneficial effects on CRF. Previous evidence syntheses provided promising but inconclusive results when focusing on the effects of resistance training.
To evaluate the effects of resistance training on CRF in people with cancer and, specifically, to compare the effects of resistance training with no training on CRF at: different periods of treatment in relation to anticancer therapy (before, during, or after anticancer therapy); different periods of assessment (up to 12 weeks after the intervention, between more than 12 weeks and less than six months after the intervention, or six months or longer after the intervention).
Moreover, we wanted to compare the effects of resistance training with no training on quality of life (QoL), adverse events, depression, and anxiety.
We performed an extensive literature search in eight databases including CENTRAL, Medline, and Embase in October 2023. We searched trial registries for ongoing studies, and we integrated results from update searches of previously published Cochrane reviews.
We included randomised controlled trials (RCTs) that compared resistance training with no training in adults with any type of cancer who received resistance training initiated before, during, or after anticancer therapy. Eligible RCTs needed to evaluate CRF or QoL. Resistance training had to be structured, last for at least five sessions, and include face-to-face instruction. We excluded studies that randomised fewer than 20 participants per group.
We used standard Cochrane methodology. For analyses, we pooled short-term, medium-term, and long-term effects (i.e. up to 12 weeks, between more than 12 weeks and less than six months, and six months or longer, after the intervention). We assessed risk of bias and certainty of the evidence using Cochrane's risk of bias tool (RoB 1), and the GRADE approach, respectively.
We included 21 RCTs with a total of 2221 participants, with diverse types of cancer, who received resistance training initiated during (14 studies), or after (7 studies) anticancer therapy. None of the studies investigated the effects of resistance training initiated before anticancer therapy. Here, we present the results on CRF, QoL, and adverse events. Results on depression and anxiety are reported in the full review.
Resistance training during anticancer therapy
Resistance training probably has a beneficial effect compared with no training on short-term CRF (mean difference (MD) on Functional Assessment of Chronic Illness Therapy - Fatigue scale (FACIT-Fatigue) 3.90, 95% confidence interval (CI) 1.30 to 6.51; scale from 0 to 52, higher values mean better outcome, minimal important difference (MID) 3; 12 RCTs, 1120 participants; moderate-certainty evidence). The evidence is very uncertain about the effect of resistance training compared with no training on medium-term CRF (MD on Multidimensional Fatigue Inventory −8.33, 95% CI −18.34 to 1.68; scale from 20 to 100, higher values mean worse outcome, MID 11.5; 1 RCT, 47 participants; very low-certainty evidence). The evidence is very uncertain about the effect of resistance training compared with no training on long-term CRF (MD on FACIT-Fatigue −0.70, 95% CI −4.16 to 2.76; 1 RCT, 133 participants; very low-certainty evidence).
Resistance training may have a small beneficial effect compared with no training on short-term QoL (MD on EORTC QoL Questionnaire C30 - global health (QLQ-C30) 4.93, 95% CI 2.01 to 7.85; scale from 0 to 100, higher values mean better outcome, MID 10; 12 RCTs, 1117 participants; low-certainty evidence). The evidence is very uncertain about the effect of resistance training compared with no training on medium-term QoL (MD on QLQ-C30 6.48, 95% CI −4.64 to 17.60; 1 RCT, 42 participants; very low-certainty evidence). The evidence is very uncertain about the effect of resistance training compared with no training on long-term QoL (MD on Functional Assessment of Cancer Therapy - Anemia (FACT-An) 0.50, 95% CI −8.46 to 9.46; scale from 0 to 188; higher values mean better outcome, MID 7; 1 RCT, 133 participants; very low-certainty evidence).
Only two RCTs (116 participants) reported data on adverse events for both the resistance training and the control arm. The evidence is very uncertain about the effect of resistance training compared with no training on the occurrence of adverse events (very low-certainty evidence).
Resistance training after anticancer therapy
The evidence is very uncertain about the effect of resistance training compared with no training on short-term CRF (MD on Chalder Fatigue Scale −0.27, 95% CI −2.11 to 1.57; scale from 0 to 33, higher values mean worse outcome, MID 2.3; 3 RCTs, 174 participants; very low-certainty evidence).
Resistance training may have a small beneficial effect or no effect compared with no training on short-term QoL (MD on QLQ-C30 3.87, 95% CI −1.22 to 8.97; 4 RCTs, 243 participants; low-certainty evidence).
None of the studies reported data on medium-, or long-term effects on CRF or QoL.
Only three RCTs (238 participants) reported data on adverse events for both the resistance training and the control arm. The evidence is very uncertain about the effect of resistance training compared with no training on the occurrence of adverse events (very low-certainty evidence).