Exercise as therapy for COPD – is exercise advisable for smokers with lung disease?

This article shows that targeted endurance training can significantly improve performance and quality of life in COPD – even without additional oxygen administration, provided there is no need for oxygen.

• Explains how quickly resilience and everyday symptoms improve through regular training.
• Compares training with and without oxygen, as well as constant load and interval training – with similar effects.
• This shows that above all, sufficiently high intensity and individually appropriate training methods are crucial for the success of the therapy.

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Reading time: 5 minutes

Chronic obstructive pulmonary disease (COPD) is more commonly known as "smoker's lung." The symptoms remain the same: coughing, increased phlegm production, and shortness of breath during exertion. When performed correctly, exercise can be a therapeutic alternative to medication for COPD.

Is it possible to do sports with COPD?

Physical activity, and above all regular exercise, is a cornerstone of non-drug therapy for COPD. Even after just a few weeks, performance improves, which is noticeable in everyday life as well as in leisure activities with family and friends. This also increases quality of life. Both of these effects have been clearly demonstrated in numerous studies. However, the question of how the best results can be achieved has not yet been definitively answered. This involves three areas:

• Do people who do not require supplemental oxygen benefit from oxygen intake during training?
• Is training with constant intensity or interval training more beneficial?
• How far can physical performance be improved ?

Other important topics are

• the different effects of training with large and small muscle groups and
• The comparison between strength and endurance training.

The oxygen supply during training is intended to enrich the blood flowing from the lungs to the muscles with more oxygen , thus increasing muscle oxygenation. This should increase the possible training load for people with smoker's lungs. In this way, the training effects can also be enhanced .

What effect does oxygen supply during training have on COPD patients?

Although an earlier study showed a benefit of oxygen supply during exercise for people with smoker's lung compared to a control group with the same condition who breathed normal air, these results could not be confirmed in later studies.

Recent study results on the treatment of COPD through exercise

The study

A recent study involved COPD patients exercising on a stationary bike for half an hour three times a week , initially at 70% of their current capacity. The workload was then increased by 5% every three weeks. Half of the participants received 4 liters of oxygen per minute via nasal cannula, while the other half received room air at the same flow rate. The patients themselves were unaware of which group they belonged to.

The result

Both groups benefited from the training to a comparable extent: After just twelve weeks , maximum performance had increased – by 20% on the bicycle and by 12% in the 6-minute walk test. Quality of life, as measured by a questionnaire, also improved significantly. Even at the end of the study, after a total of 24 weeks, there was no difference between oxygen and air supply.

Interpretation of the results

This was unexpected for us because a smaller preliminary study had shown that an increased oxygen concentration in the inhaled air had a positive effect on improving performance. That study also included a control group that received ambient air.

The primary difference between the two studies lies in the fact that the COPD patients in the initial study breathed through face masks, through which one group received a constant oxygen concentration twice that of ambient air. With nasal cannula administration, the amount of additional oxygen that can reach the lungs depends, among other things, on the ratio of mouth to nasal breathing . And during strenuous activity, everyone tends to increase mouth breathing, thus reducing the amount of additional oxygen absorbed into the lungs.

Which type of training is more effective in treating smoker's lung?

Endurance training can generally be divided into two different types of training: constant-intensity training , where the intensity remains the same throughout a single session, and interval training , where phases of high and low intensity alternate regularly. For a long time, only the first type was used with patients.

The research findings – constant exercise intensity vs. interval training in COPD

In 1991, Casaburi's research team demonstrated that intensive training is superior to less intensive training . For the first time, it was shown that physiological parameters adapt positively to regular activity in both people with healthy lungs and those with smokers' lungs. In particular, the ability of muscles to supply the energy required for muscle contraction using oxygen and the nutrients carbohydrates and fats is increased.

To investigate whether such adaptations develop more strongly under interval or constant-intensity exercise , patients have previously been divided into two groups training according to the principles described. For comparability, the total workload was kept the same.

A more recent study – a 24-week comparison

We investigated the same question intra-individual over 24 weeks. As in the other studies, two groups initially trained at a constant intensity and in intervals . The constant training group trained for 30 minutes at 70% of their maximum power, which was determined using a progressively increasing test. The other group alternated between 4 minutes of training at 60% and one minute at 110% of their maximum power during the same period. The workload was increased by 5% every three weeks.

Halfway through the study, an interim test was administered . Afterward, the groups switched training methods. Consistent with the results of other studies, we found no significant difference between the adaptations to the two training methods. Additionally, we asked the participants about their preferred type of exercise . Approximately 30% of the patients preferred constant training, 40% preferred interval training, and the remaining 30% were indifferent.

These results are very positive for the practical implementation of training measures. Therefore, it makes no sense to place greater emphasis on one particular type of training, and each person can choose their preferred training method or switch between them to avoid monotony.

In this study, we also discovered something surprising : Although the intensity was adjusted to the current results after the interim test, and performance was progressively increased as in the first 12 weeks, there was no further increase in physical fitness until week 24. Of course, such results can only be interpreted in light of the conditions that actually prevailed.

Can lung function improve again in COPD?

This suggests that with 30-minute endurance cycling sessions performed three times a week, the limit of training adaptation is reached within 12 weeks, even with increasing intensity. This could be attributed to the fact that lung function is hardly improved by training the leg muscles, and this becomes a limiting factor at a certain performance level.

The next steps should be to investigate whether strength training – in isolation or in combination with endurance training – allows for greater gains and whether endurance training with smaller muscle groups , which is less limited by lung function, allows for a greater increase in performance.

Conclusion: No significant benefit from oxygen support

In summary, for exercise therapy using endurance training, it can be stated that oxygen support offers no significant advantage for patients who do not require supplemental oxygen, and interval training is equivalent to continuous training . In both forms, the intensity of the exercise must be sufficiently high to achieve significant improvements in physical performance. The correct intensity can be easily determined by a bicycle ergometry test performed by a specialist.