OAC SETS NEW STANDARDS IN CANCER THERAPY AND AFTERCARE WITH 4×4 TRAINING
Clear evidence: exercise can improve cancer survival by one third – as effectiveLY as medication and without any side effects.
The world’s first study with patients from the USA, UK, Australia, France, Canada and Israel has shown that a structured exercise program after cancer treatment can drastically reduce the risk of death as well as the risk of cancer recurrence or the development of a new cancer. The results were presented at the annual meeting of the American Society of Clinical Oncology, ASCO for short – marking a breakthrough in cancer research.
Dr. Julie Gralow, ASCO’s chief medical officer, said about the study’s results: “For the first time in the history of medicine, there is clear evidence that exercise can prevent cancer recurrence and death better than many of the drugs currently prescribed to patients.”
A breakthrough in cancer medicine with convincing numbers
The landmark study, published in the New England Journal of Medicine and presented at the ASCO Annual Meeting, provides the clearest evidence to date that physical activity can be life-saving after cancer treatment. The results are impressive: exercise can reduce the risk of death in cancer patients by 37 percent and the risk of the disease returning or a new tumor developing by 28 percent.
What does this mean in concrete terms?
- Patients who exercised regularly with personal trainers after their treatment had a 28 percent lower risk of relapse after five years.
- After eight years, the risk of death was even 37 percent lower compared to patients who only received general health advice.
Important to know: The study included 889 patients with colorectal cancer who took part between 2009 and 2023. Most were stage III, and participants worked with coaches twice a month over three years to help them reach a goal of 3 to 4, 45 to 60-minute walks per week. Many also chose other activities such as kayaking or skiing.
Why is this so important?
Dr. Julie Gralow explains: “We called the session in which the results were presented ‘As Good as a Drug’. I would even put them in the ‘Better than a Drug’ category because they have no side effects.”
And further: “Exercise is not only safe, but can even be more effective than many drugs that are expensive and associated with side effects.”
Prof. Charles Swanton from Cancer Research UK concludes: “This study shows how exercise can improve health and increase survival after cancer treatment.”
Sport is the key to a better quality of life
The figures speak for themselves: regular, targeted exercise can significantly reduce the risk of cancer recurrence – and even better than many drugs. For cancer patients, this means that exercise is not an add-on, but an essential part of aftercare.
OAC is grateful for these study results, as they finally prove what OAC founder and cancer survivor Petra Thaller has known for 10 years: sport, outdoor sport in particular, offers a highly effective strategy for improving quality of life in the fight against cancer. Already back in 2018, Petra and sports scientist Dr. Thorsten Schulz published the book Outdoor against Cancer – Wie Bewegung und Sport in der Natur im Kampf gegen Krebs wirken.
In close collaboration, exercise physiologist Dr. Rūdolfs Cešeiko from Stradiņš University in Riga and OAC’s scientific team have recently further developed the 4×4 Training for use with cancer patients. While Dr. Cešeiko transferred the method to the oncological context, OAC brought in the crucial perspective to consistently move the training outside into nature. An effective synergy, with the aim of offering cancer patients a unique opportunity to improve their quality of life and actively participate in their recovery.
The 4×4 Training – a highly effective strategy for cardiovascular and metabolic health
The 4×4 Training, consisting of 4 intervals of higher-intensity aerobic exercise, each lasting 4 minutes, followed by three minutes of active recovery, has proven to be a highly effective method for improving cardiovascular and metabolic health. Its effectiveness is based on robust central and peripheral physiological adaptations.
Central effects
At a central level, one of the main benefits of the 4×4 Training is an increase in stroke volume, i.e. the amount of blood the heart ejects with each beat. As the maximum heart rate remains relatively constant with regular training and tends to decrease with age, the improvement in stroke volume leads directly to an increase in maximum cardiac output. This increase considerably improves the oxygen supply to the working muscles and leads to significant improvements in maximum oxygen uptake (VO₂max) – a crucial factor for aerobic performance and health.
Peripheral effects
In addition to the central cardiovascular adaptations, the 4×4 Training also brings about important peripheral changes. These include increased mitochondrial density and function, improved oxygen extraction in the muscles and improved metabolism. The repeated physiological stress from the intervals also improves endothelial function, resulting in greater flexibility of blood vessels and increased availability of nitric oxide – a hallmark of a healthy endothelium.
Further benefits
In addition, neuromuscular coordination improves and motor unit recruitment becomes more efficient, while insulin sensitivity increases in parallel – a crucial factor for metabolic health. In summary, these central and peripheral adaptations are the basis for the 4×4 Training being an extremely efficient and comprehensive method to increase cardiovascular performance and physical resilience – even in different patient groups, including people with cancer.
After 100 successful training sessions in Riga, the 4×4 Training has now also been celebrating successes in Munich since April 2025. In an interview with Dr. Tom Degenhardt, OAC’s Medical Director, we discussed what makes the modified 4×4 Training so special and, above all, effective.
Interview with OAC’s Medical Director
In the interview with OAC author Susa Schreiner, Tom Degenhardt, MD, explains how training significantly improves maximal oxygen uptake (VO₂max), promotes cellular adaptations and optimizes metabolism – and the specific benefits for people with a cancer diagnosis.
OAC: The 4×4 Training is attracting a lot of attention and is THE training method in semi-professional sport par excellence. What makes this scientifically researched training method so special?
Dr. Tom Degenhardt, MD: The 4×4 Training is a type of interval training consisting of a 15-minute warm-up followed by 4 intervals of 4 minutes each at 85 to 95 percent of maximum heart rate (HRmax). This is alternated with three minutes of active recovery between the intervals, at around 60 to 75 percent of your maximum heart rate. The last recovery phase is also the cool down. This scientifically researched training method has its origins in competitive sport, where it was established by Norwegian sports scientists.
Interval training has also been used safely and successfully for years in the treatment of patients with heart diseases.
OAC: What are the three top effects?
Dr. Tom Degenhardt, MD: The 4×4 Training has been proven to significantly improve maximum oxygen uptake, also known as VO₂max. VO₂ is a key indicator of cardiorespiratory fitness. Studies show that regular training using this method can significantly increase VO₂max, which significantly increases endurance performance. This increase is usually greater than with classic, moderate or even intensive endurance training.
Another effect of regular 4×4 Training is cellular adaptation: it promotes mitochondrial biogenesis and therefore energy production at cell level.
A third effect is metabolic optimization. Fat metabolism is improved and insulin resistance can be reduced – this is important, for example, in the prevention and treatment of chronic diseases such as diabetes and atherosclerosis.
OAC: Let’s talk about maximum oxygen uptake again. Why is VO₂max considered a crucial parameter for health?
Dr. Tom Degenhardt, MD: A high VO₂max value is strongly associated with reduced overall mortality. It reflects the performance of the heart, lungs and muscles – central systems for long-term health. The cardiovascular system adapts through repeated exercise close to the maximum heart rate (85-90% HRmax): The heart’s stroke volume increases, the heart works more efficiently and can transport more blood per beat. This is a key mechanism in improving performance and the health of the cardiovascular system.
My Latvian friend and colleague, Dr. Rūdolfs Cešeiko who has conducted research into the “Influence of maximum strength training on the quality of life of women with breast cancer undergoing treatment”, has optimized the training together with OAC’s scientific team and taken it outside into nature. The 100th 4×4 Training session took place in Riga at the end of May. The 4×4 Training has now also been available in Munich since April 2025. This is a big step in the right direction.
OAC: That’s right, because the main aim of OAC is to get cancer patients moving, outdoors in nature. What are the specific effects for cancer patients?
Dr. Tom Degenhardt, MD: In my opinion, one of the most important aspects is the increase in quality of life and performance in everyday life, for example by reducing fatigue. In addition, chemotherapy and radiotherapy are better tolerated. The aforementioned effects such as cellular adaptation and metabolic optimization apply to all exercisers and, accordingly, there are also positive effects on immune function and quality of life for cancer patients.
OAC: Absolutely, we are already getting this feedback from our participants. One point is still open, namely the significant improvement in maximum oxygen uptake V̇O₂max. There are certainly positive effects for cancer patients here too, or how does this value change?
Dr. Tom Degenhardt, MD: The VO₂max value can increase by up to 10% within 8 to 12 weeks through the 4×4 Training. With continuous training, the effects remain stable – without training, however, the value drops again. It’s worth sticking with it. The training can be adapted to the current physical condition at any time according to individual criteria such as the percentage of maximum heart rate or the subjective load scale. This is also what makes the training so diverse: the participants are guided by their own performance level and daily form and not by the group. For some, sub-maximal exertion is a sprint, for others high intensity means four minutes of fast walking. This integrative approach makes training even more exciting.
OAC: We can only agree with that. With our 4×4 Training, we want to invite people to exercise in the fresh air, with or without a cancer diagnosis. However, in our last question, we would like to focus specifically on cancer patients. Tom, what are the long-term effects of regular 4×4 Training?
Dr. Tom Degenhardt, MD: In the long term, not only does physical resilience improve, but also mental stability. In addition, the risk of relapse can be reduced and the tumor microenvironment can be favorably influenced.
About Dr. Tom Degenhardt, MD:
Tom Degenhardt is a specialist in general medicine and gynecology with additional qualifications in sports medicine and palliative medicine. After many years at the Ludwig Maximilian University of Munich, most recently as site manager of the Breast Center in Großhadern, his focus today is on holistic care as a GP in Wolfratshausen. He has been the Medical Director of Outdoor Against Cancer since 2022.
