Final answer:
The most beneficial cooldown activities after a leg-strengthening routine are the standing quadriceps stretch and relaxation breathing because they help in preventing injuries and promoting muscle recovery.
Step-by-step explanation:
After a leg-strengthening routine, an effective cooldown is essential to help lessen muscle soreness. The most suitable options for cooldown exercises would be low-intensity activities that help the body transition to a state of rest. Of the options listed, jogging in place may initially seem like a good choice; however, it's typically more of a warm-up activity rather than a cool down due to its aerobic nature. Burpee exercises, being an anaerobic high-intensity exercise, are not suitable for a cool down and could actually increase muscle soreness. Considering the goal of promoting recovery and flexibility, the best choice would be to include a standing quadriceps stretch, which directly targets the muscles used during leg strengthening. Additionally, relaxation breathing is a valuable tool to facilitate overall recovery, helping to calm the nervous system and promote better muscle recovery.
It's important to understand that effective cooldown routines often involve flexibility exercises such as stretching to improve the range of motion and prevent injuries. These exercises are designed to gently lengthen the muscles that have been contracted during a workout, aiding in the reduction of muscle tightness and soreness. Therefore, amongst the given options for a cooldown routine after a leg-strengthening workout, the standing quadriceps stretch and relaxation breathing would be the most beneficial.