That's because the right answer is variety, mixing and matching types of exercise to keep the body guessing and improving.
"The body adapts to the demands we put on it," said Dr. Russell Camhi, who works in primary care sports medicine for Northwell Health's Orthopaedic Institute in East Meadow, N.Y.
"If we do the same exercise regimen over and over, results are bound to plateau," he explained. "Now this doesn’t mean you have to change exercises every day or every week, but a little variety will help the body change and grow."
The key to weight loss is a blend of exercise and nutrition, with the latter responsible for about 80% of the heavy lifting, according to Camhi.
It’s important to reduce calories while increasing physical activity, according to the Mayo Clinic, which recommends cutting about 500 to 750 calories a day to lose 1.5 pounds per week.`
Though diet plays a bigger role than exercise, physical activity can help with weight maintenance, as well as counter loss of bone density and muscle mass, the Mayo Clinic noted.
A high amount of physical activity would be necessary to lose weight unless also adjusting diet, according to the U.S. Centers for Disease Control and Prevention. It's not clear exactly how much exercise would be needed for weight maintenance because that varies greatly by person, according to the agency.
“Exercise is important and imperative for health and longevity, but all efforts to lose weight will fail without a nutrition program,” Camhi said.
A recent study published in the journal eBioMedicine found that for certain people who are slow to lose weight, exercise had an even bigger impact.
The ability of muscle cells to burn energy varies widely between people, senior study author Mary-Ellen Harper, research chair of mitochondrial bioenergetics at the University of Ottawa in Canada, noted when the study was published.
"We found that the slow losers responded much better to exercise than the fast losers did," Harper said.
Best exercise combo for weight loss
If a person's primary goal is to lose weight, Camhi suggests a combination of steady-state cardio and weight training.
The cardio session should be around 30 minutes, repeated about two to four times per week.
Weight-training sessions should be 30 to 60 minutes with sets of 8 to 12 reps per exercise and low rest time in between sets.
"Steady-state cardio will burn fat when in the target HR [heart rate] zone," Camhi said.
It’s easy to calculate the target zone. Just take 220 and subtract your age from that number to determine your maximum heart rate.
Your target heart rate zone is 50% to 70% of that number.
Heart rate monitors can be useful to track those numbers, Camhi said, but there are less technical ways to measure your exertion levels.
"Fat-burning zone is the point where you can hold a conversation, but it is a little challenging as you are primarily breathing through your mouth, not just your nose," Camhi said.
It's important to start a cardio routine wisely. Begin with low-impact exercise, such as biking, swimming or using an elliptical machine, Camhi said. Walk on the treadmill, with running intervals.
Later, work up to full running or a step-climbing machine, once you’ve built up tolerance and have less risk of injury.
"Good entry weight-training exercises are squats, lunges, step-ups, pushups, rows, and planks," Camhi said. "It is imperative to include legs and large muscle groups when weight training for weight loss."
It's also important to keep your workouts fun to stay motivated, advises the U.S. National Library of Medicine (NLM). Take a class or work out with a buddy. Try dancing, yoga, karate or softball.
Meanwhile, cut back on screen time or other sedentary behaviors.
"The most important thing is that you do exercises that you enjoy and are practical, so that it is easier to sustain what you are doing," the NLM suggests.
Nutrition.gov suggests checking your body mass index (BMI) before you start and working with your doctor to come up with a goal for your weight loss.
Set an intermediate goal, such as 10 pounds. Even small amounts of weight loss can pay off in big health benefits, the website advises.
If you get stuck, be ready to shake it up.
"If progress plateaus for more than one to two weeks, it is time to change up your exercise routine," Camhi said.