Hormone therapy for prostate cancer typically causes significant muscle loss. Skeletal muscle releases Interleukin-7 (IL-7), a signalling protein that supports the production of new immune cells. Therefore, losing muscle during cancer treatment may actively weaken the immune system. The goal of this clinical trial is to investigate if a 12-week supervised resistance exercise (strength training) programme can prevent this muscle loss and increase levels of IL-7.

The main questions it aims to answer are:

• Does a 12-week strength training programme raise resting IL-7 levels and increase newly formed immune cell counts?
• Does a single session of strength training trigger an immediate release of IL-7?
• To what extent do exercise-induced improvements in muscle mass and strength translate into reduced fatigue, better physical function, higher quality of life, and improved cardiometabolic health?
• Is the exercise programme safe and well-tolerated during hormone therapy?

Researchers will compare a Resistance Exercise Group to a Usual Care Group to see the effects of strength training against standard medical care.

Participants will:

• Attend a screening visit to check eligibility.
• Complete baseline assessments, including body composition scans, blood tests, fitness tests, and questionnaires.
• Be randomly assigned to either the exercise group or the usual care group.
• Complete three supervised strength training sessions per week for 12 weeks, if assigned to the exercise group.
• Continue with standard medical care, if assigned to the usual care group.
• Repeat all assessments at the end of the 12 weeks.
• Perform one short exercise session during the final visit, with extra blood samples taken before and after to track immediate changes