Editor's note: This is the second in a two-part series. See part one:.
After surviving cancer, patients may find it difficult to return to the same level of physical activity that they were used to before their diagnosis.
However, staying active is extremely important. Dr. Karen Basen-Engquist, director of MD Anderson's Center for Energy Balance in Cancer Prevention and Survivorship in Houston, Texas, told CBSNews.com that studies show exercise can lower rates of relapse for people with breast and colorectal cancers.
"There may not even be a need for a special program. You can find recommendations on the American Cancer Society website about the recommendations for cancer survivors and how to get started and really take it from there on your own," she said.
The National Cancer Institute adds that studies have shown that continuing to work out after being diagnosed with breast cancer may help improve quality of life, reduce fatigue and help balance out energy levels.
Basen-Engquist's research focuses on whether there are biomarkers -- biological clues in the body -- that will tell scientists why exercise is so beneficial in the fight against cancer and how to tap into these biological processes in order to reduce the risk of relapse even further.
The biggest problem cancer survivors face when trying to work out is that they don't know what their "new normal" energy levels are, Nancy Campbell, a clinical exercise physiologist at Dana-Farber Cancer Institute in Boston, told CBSNews.com. Some people feel great and start out doing too much, which leads to them to crash and become exhausted.
Campbell said it's important that cancer survivors start out slowly. Listen to your body, and if you notice any side effects like shortness of breath, chest pain or fatigue, it may be time to dial things down a notch.
Finding a trainer who will know how to specifically work with a cancer survivor's needs can also help. The American College of Sports Medicine offers a cancer exercise trainer certification. However, Campbell admits there are far fewer certified trainers than there are cancer patients who need them.
Another option is to look for fitness classes specifically geared towards cancer survivors in your area. Campbell, who co-teaches a free exercise class for cancer patients and survivors at Dana-Farber twice a week, suggested looking at the hospital where you were treated to see if they have any programs or places they can refer you to.
One local community option may be Livestrong at the YMCA. Livestrong and the YMCA partnered to create a research-based program that focuses on physical activity and well-being programs for cancer survivors. The 90-minute classes meet twice a week for 12 weeks. The program began in 2008 and is currently held in 300 communities in 37 states.
"We heard through ongoing conversations...that cancers survivors wanted to exercise and to improve their physical health, but because of their treatment, they were unsure of what was safe and effective," Haley Justice Gardiner, Livestrong's manager of community programs and engagement, told CBSNews.com.
The program is free. Gardiner explained that both organizations realized that with the high costs of cancer treatment, many survivors might not have much left to pay for a gym membership. This way they can reclaim their physical health without any great financial burden.
"Hopefully this will diminish some side effects they had during their treatment and help them develop supportive relationships with other cancer survivors that join the program," Ann-Hillary Heston, project manager at the YMCA of the USA, added to CBSNews.com.
If an exercise program specifically for people who battled cancer doesn't exist in your area, something every cancer survivor can start doing without worrying is walking, Basen-Engquist pointed out.
"We all know how to walk," Campbell said. "Other than a good pair of shoes, you don't need any special equipment."