Final answer:
High-intensity interval training (HIIT), weightlifting, and circuit training are suitable activities to increase anaerobic capacity.
Step-by-step explanation:
One activity that is most appropriate to increase anaerobic capacity is high-intensity interval training (HIIT). HIIT involves short bursts of intense exercise followed by brief recovery periods. For example, the client can perform sprints for 30 seconds followed by a 30-second rest, and repeat this cycle several times.
Another activity that can help increase anaerobic capacity is weightlifting. Weightlifting exercises, such as squats and deadlifts, require a high level of effort and energy for a short duration, which can improve the client's anaerobic capacity.
Circuit training is also a suitable activity to include in the training program. It involves performing a series of exercises or stations with minimal rest in between. This challenges the client's anaerobic system as they continuously push their limits.