Before knee replacement surgery, you should focus on strengthening your quadriceps with exercises such as straight leg raises, mini-squats, sit-to-stands, step-ups and stationary biking. Kristen Lucek was in her late 30s when she began experiencing pain in her hip that felt like a knife whenever she bent over. It got worse, and within two years, Lucek, a gym owner in San Diego, couldn’t pick up a kettlebell while coaching. She became depressed and gained weight.