3.8 Neoplastic, Immunologic & Hematologic Disorders (cancer, HIV/AIDS, anemia)

Oncology, immunologic, and hematologic populations require the clinical exercise physiologist to integrate treatment history and current laboratory values into every exercise decision, since the safe intensity and mode can change from week to week as treatment progresses.

Cancer and Oncology Exercise Physiology

ACSM has established exercise oncology as a core clinical population because physical activity improves cancer-related fatigue, physical function, and quality of life during and after treatment, but treatment effects create specific precautions. Cancer-related fatigue is a persistent, treatment-driven fatigue that is not proportional to activity level and does not fully resolve with rest; unlike deconditioning fatigue, it often responds well to individualized aerobic and resistance exercise, though intensity should be adjusted symptom-by-symptom.

Key treatment-related effects the CEP must screen for:

• Cardiotoxicity: anthracycline chemotherapy agents (e.g., doxorubicin) and HER2-targeted therapy (trastuzumab) can cause dose-related or treatment-related reductions in left ventricular ejection fraction; patients with a cardiotoxicity history should be treated similarly to other cardiomyopathy/heart-failure populations, with attention to exertional dyspnea and fatigue.
• Radiation fibrosis: radiation therapy can cause progressive fibrotic tissue changes in the treatment field (e.g., pulmonary fibrosis after chest radiation, restricted shoulder range of motion after axillary/chest-wall radiation), which may limit both ventilatory capacity and joint mobility.
• Corticosteroid myopathy: prolonged corticosteroid use (common in many treatment regimens) can cause proximal muscle weakness, particularly affecting hip and shoulder girdle strength and functional tasks like stair climbing or rising from a chair.
• Lymphedema: after lymph node dissection or radiation to nodal basins (most classically axillary dissection in breast cancer), impaired lymphatic drainage can cause chronic limb swelling; while historical advice restricted resistance exercise in the affected limb, current evidence supports properly progressed, supervised resistance training as safe and beneficial, provided it starts conservatively and any swelling changes are monitored.

Blood-Count-Based Exercise Precautions

Because chemotherapy and certain cancers themselves suppress bone-marrow production, exercise intensity in oncology populations should be checked against current complete blood count values. Widely cited (though not universally standardized, since high-quality controlled evidence is limited) clinical guidance uses these general reference points:

These are general clinical reference points intended to guide caution and intensity modification rather than rigid cutoffs, and exercise decisions in actively treated oncology patients should always be coordinated with the treating oncology team.

HIV/AIDS

HIV progressively depletes CD4+ T-helper lymphocytes, and disease staging is tracked by CD4 count alongside viral load; untreated advanced disease (historically defined at a CD4 count below 200 cells/mm^3, or the presence of an AIDS-defining illness) leaves patients vulnerable to opportunistic infections. Antiretroviral therapy (ART) has transformed HIV into a manageable chronic condition, but certain regimens are associated with lipodystrophy (abnormal fat redistribution — peripheral fat loss with central/visceral fat accumulation) and metabolic changes including dyslipidemia and insulin resistance, which raise cardiometabolic risk similarly to metabolic syndrome. Regular aerobic and resistance exercise is broadly beneficial for HIV-positive individuals on stable ART, improving cardiorespiratory fitness, body composition, and quality of life, with precautions driven mainly by current CD4 status, symptom burden, and any active opportunistic infection rather than the diagnosis itself.

Hematologic Considerations

Anemia, regardless of underlying cause (iron deficiency, chronic disease, chemotherapy-induced, or CKD-related as discussed elsewhere), reduces the oxygen-carrying capacity of blood, which directly lowers VO2max and exercise tolerance independent of cardiac or pulmonary status; patients often report disproportionate fatigue and dyspnea relative to workload. Sickle cell trait and sickle cell disease carry a risk of exertional sickling — red blood cells deforming into a rigid sickle shape under conditions of hypoxia, acidosis, dehydration, or heat stress, which can obstruct microvasculature and, in severe cases, cause exertional collapse or sudden death. Risk rises sharply with extreme heat, high altitude, and dehydration, so exercise programming for these patients should emphasize gradual acclimatization, generous hydration, avoidance of extreme environmental conditions, and immediate cessation of exercise if the patient reports unusual muscle pain, weakness, or cramping.

Safety Considerations

Always check the most recent complete blood count and treatment schedule before prescribing intensity in an actively treated oncology patient, monitor lymphedema-affected limbs for swelling changes rather than avoiding resistance training outright, confirm CD4 count and any active infection in HIV patients before intensive programming, and apply conservative heat/hydration management for any patient with sickle cell trait or disease.