There are different prehabilitation regimens, but two typical cancer prehabilitation approaches, namely a unimodal and a multimodal cancer prehabilitation regimen [3,4,5,6]. Regular physical activity such as exercise is part of both approaches in prehabilitation and has been shown to be very relevant in the treatment and rehabilitation of cancer patients over the last 25 years [1, 2, 5, 15,16,17,18,19]. Exercise can improve functional health, which has positive effects on physical performance, mental health, and quality of life and—in some types of cancer—also on survival [15, 16]. For cancer patients, individually tailored (targeted) exercise is safe and feasible, even in cases of complex health profiles [1, 2, 5, 15,16,17,18,19]. Therefore, most patients can benefit through exercise, regardless of individual circumstance (comorbidities, medications) or the burden of disease [1, 2, 5, 15,16,17,18,19]. Today, exercise can be seen as a kind of medicine in oncology [15, 16]. A multidisciplinary and multiprofessional approach is required, with all members of the team promoting physical activity to ensure that patients benefit from it [15, 16, 19]. It has been shown that most cancer patients can benefit from exercise and therefore should start to be physically active as soon as possible [1, 2, 15,16,17,18,19].
Unimodal cancer prehabilitation regimen, which consist of exercise only have been most frequently cited, showing effectiveness in reducing postoperative stress and complications, duration of hospital stay, and improving clinical outcomes by optimizing cardiopulmonary reserve prior to surgery [5,6,7,8,9,10,11,12,13,14, 20,21,22,23]. There is growing scientific evidence supporting the effects of exercise in cancer prehabilitation [5,6,7,8,9,10,11,12,13,14, 20,21,22,23]. Regarding exercise, it is important to mention that each patient has unique and individual comorbidities and individual physical performance capacity. Therefore, exercise has to be recommended on an individual basis to meet these specific needs [1, 2, 5, 19]. A thorough medical history, clinical examination, some laboratory parameters, ECG and echocardiograph findings, exercise testing, spirometry, and in some cases radiographic findings and bone scans are the basis for planning individual exercise programs for prehabilitation [1, 2, 5, 15, 16, 19]. Therefore, the exercise plan has to be based on an adequate baseline assessment, for example, exercise testing and echocardiography in endurance exercise. Furthermore, patients should be supervised during prehabilitative medical exercise. To our opinion, telerehabilitative (tele-prehabilitative) tools could also be very useful for monitoring patients—not only, but especially during the pandemic [1, 2, 5, 19].
Exercise aimed at strengthening skeletal muscles and to increase muscle mass, and exercise to increase endurance capacity have proven benefits for cancer patients [1, 2, 5, 15, 16, 19]. Endurance exercise, especially high-intensity interval training (HIIT, exercise) is a modern, promising option in the prehabilitation of cancer patients. HIIT seems to be safe and effective in rehabilitation but also during the pretreatment (prehabilitation) time period [5, 18].
In the field of cancer rehabilitation, there are existing tumor boards in order to plan rehabilitation and supportive strategies. Very challenging cases are discussed in an interdisciplinary and multiprofessional setting to determine whether they are able to perform exercises [1, 2, 19]. In our opinion, such an interdisciplinary and multiprofessional team process (a so-called “prehabilitation board”) could be an option to improve exercise interventions in prehabilitation. Such a prehabilitation board should define individual prehabilitation (especially exercise) concepts for “challenging” cancer patients with their individual functional deficits, medical conditions and risks. For patients who are not allowed to perform active exercise in the pretreatment time period (e.g., due to immobilization, severe cardiovascular comorbidity or very high risk of seizures or pathological fractures), neuromuscular electrical stimulation (NMES) seems to be a useful supportive treatment to increase muscular strength and endurance capacity prior to acute cancer treatment [1, 2, 19].
The second approach, the multimodal cancer prehabilitation regimen, represents a combination of treatments and consists of various parts such as patient education and information, exercise, nutrition, psychologic counseling such as psycho-oncology, smoking cessation and reduction of alcohol consumption. Most experts seem to prefer this multimodal approach. Nevertheless, there can be obstacles to applying the concept, such as urgency in cancer diagnosis and treatment [3, 4]. There are already opportunities to further improve access to and provision of multimodal prehabilitation concepts [3, 4, 6].