Tl;dr from the article, they used flow cytometry to quantify different cell populations in the blood, and noted that the proportion of CD8+ T cells (cytotoxic, the kind of immune cells that recognize and kill cancer cells, among other things) increases after exercise and returns to baseline 30 min later.
Claiming that this supports the idea that cancer patients could benefit* from exercise is a pretty big overstep of scientific inference.
Tl;dr from the article, they used flow cytometry to quantify different cell populations in the blood, and noted that the proportion of CD8+ T cells (cytotoxic, the kind of immune cells that recognize and kill cancer cells, among other things) increases after exercise and returns to baseline 30 min later.
Claiming that this supports the idea that cancer patients could benefit* from exercise is a pretty big overstep of scientific inference.
* = in the immune response to their cancer