Cardio then Lift? Or Lift then Cardio?
Friday, May 23rd, 2008Cardio First Boosts Post-exercise Metabolism Most
Weight training burns some calories, but not as many as running, cycling or exercising on an elliptical trainer. Weight training helps people lose weight because it increases muscle mass, which is a metabolically active tissue. The more muscle you have, the more calories you burn (metabolize) during the day. The best approach for losing weight is to combine cardio (aerobic) and resistive exercise. But, which should you do first to promote weight loss?
Exercise has a relatively small effect on caloric expenditure. Run for 30 minutes and you burn about 300 to 400 calories- the content of a medium-size chocolate bar. You continue to burn calories at a faster rate than normal after exercise is over, so the true caloric cost of exercise is more than it appears. Increasing 24-hour caloric consumption will help you cut fat slowly but surely in the months ahead.
Scientists from Brigham Young University, led by Micah Drummond, found that post-exercise metabolism increased most when people did cardio first and lifted weights afterward. Weight training by itself caused more post-exercise caloric consumption than cardio. Subjects performed seven lifts and ran for 25 minutes on a treadmill. The study examined the effects of running, weight training, running plus weight training and weight training plus running on post-exercise oxygen consumption (a measure of calories burned during recovery). The researchers concluded that people should do cardio first and then lift weights if the goal is to maximize caloric expenditure.
Combining cardio and weight training will turn you into a calorie-burning machine. Training with weights intensely after cardio turns up your metabolism for the rest of the day. Intense weight training after cardio not only boosts calorie use after exercise, but makes it possible to burn more calories in the future. Researchers from the College of New Jersey found that following weight training, heart rate and blood lactic acid returned to resting levels faster in people with the highest aerobic capacities (maximal oxygen consumption). Also, high-volume, moderate-intensity weight training caused the greatest increase in metabolic rate during recovery (post-exercise oxygen consumption). The weight-training program consisted of three workouts of four sets of squats. Intensity and volume changed with each workout (15 reps per set at 60 percent of max; 10 repetitions per set at 75 percent of max; or four repetitions per set at 90 percent of one-repetition maximum). The study showed that aerobic fitness is important even in strength athletes. Combining cardio and weight training, along with a healthy diet, is the key to a fit, lean-looking body.
Doing weight training after a cardio program has the added benefit of improving metabolic health- the efficiency of the cells and organs in managing energy, building and repairing tissue, regulating body fluids, fighting infection and preventing degenerative diseases. The metabolically healthy body can respond to challenges (e.g., high environmental temperature, high-sugar meals, cold and flu germs) and maintain a balance that scientists call homeostasis.
Managing blood sugar is an important measure of metabolic health. Several studies found that cardio plus weight training improves blood sugar metabolism- an important factor in abdominal obesity, high blood pressure and cholesterol, heart disease, stroke and some types of cancer. Researchers from the University of Massachusetts found that adding weight training to a cardio program improved blood sugar metabolism in overweight men. The men had been walking on a treadmill for 45 minutes, two days per week. Adding weight training to the workout (two sets of 15 repetitions, six exercises) increased upper-body strength by 28 percent and lower-body strength by 46 percent. Weight training caused a 25 percent decrease in blood insulin, which is important for reducing high blood pressure, cholesterol and abdominal fat and preventing type 2 diabetes.
The downside of the cardio-weight training sequence is that you may not have the strength for a high-quality weight workout. It’s difficult to do squats or lunges when your legs feel like Jell-O. If your goal is losing body fat, then cardio first may make sense. If your goal is to have large, strong, ripped muscles and minimal fat, lift first and then hit the treadmill or elliptical trainer. Doing cardio first causes the greatest increase in post-exercise metabolic rate. That doesn’t necessarily mean that this sequence causes the greatest fat loss after several months of training. Post-exercise metabolism is interesting to scientists, but fat loss is your main concern. Would you say, "Yes, I still have my large pot belly, but my metabolic rate increased by 5 percent"? Of course not, because you want results. The weight training-cardio sequence has a marked hormone response that could also cause long-term fat loss.
The Benefits of Weight Training First
Muscle growth has several required prerequisites: muscle tension, time under tension, anabolic hormones (i.e., testosterone, growth hormone, insulin-like growth factor and insulin), Amino Acids, calories and rest. Eliminate any of these and progress grinds to a halt and muscles won’t grow.
Do large muscle, compound-joint exercises (e.g., squats, bench presses) before small muscle, single-joint exercises (e.g., biceps curls, calf raises). Small muscle strength and fatigue can limit performance during large muscle, multi-joint movements. During squats or bench presses, it’s difficult to push heavy weights with fatigued calf or triceps muscles. The same is true when you try to lift after running on the treadmill for 45 minutes: your thighs, glutes and calves feel like rubber and won’t be very responsive during squats or knee extensions.
Drs. Zeljka Sporer and Howard Wenger from the University of Victoria in British Columbia, Canada found that doing aerobic exercise before weight training decreased strength performance for up to eight hours. The subjects didn’t fully recover until 24 hours after the aerobic exercise session. Decreased strength was particularly severe in the muscles used during the cardio exercise. Interval training and continuous aerobic training decreased strength equally.
The healthy lifestyle is time consuming. How do you fit in two to three days per week of weight training and five to six days per week of aerobics and still have the time and energy to work, eat, relax and sleep? One solution is to lift in the morning and run or ride a bike at night. Researchers from Ball State University found that people who followed this exercise prescription recovered fully from the weight workouts by the time they did aerobics seven hours later. "Double sessions" work best when you eat a meal or supplement containing plenty of carbs, protein and calories immediately after the morning exercise session. The beauty of this technique is that you maximize adaptation to both kinds of exercise. Doing both forms of exercise together shortchanges the kind you do last. Include double session training to save time and build well-rounded fitness.
Doing weight training first produces several powerful metabolic effects that can also promote fat burning. Muscles use glycogen (stored carbohydrate) for fuel. The body uses mainly carbohydrates when exercise intensity infcreases above 65 percent of maximum effort. Fat use increases when carbohydrate availability decreases. Training with weights first (before cardio) increases overall fat use. There are no studies showing that people who use this exercise sequence lose more weight or fat after weeks and months of training.
One promising technique for fat loss during combined weight-cardio training programs is to maximize metabolic stress during weight training by minimizing rest periods between sets. Japanese researchers, led by Dr. K. Goto- found that minimizing rest periods during weight workouts boosts hormones that promote fat use. Short rest periods (one minute) caused large increases in lactate, growth hormone, epinephrine and norepinephrine, all measures of metabolic stress. Increasing these hormones through intense weight training will cause you to burn more fat during the cardio exercise that follows.
Weights Before Cardio or Vice Versa?
- Combining weight training and cardio (aerobics) provides more benefits than either form of exercise alone.
- No study has assessed the long-term effect of exercise sequencing (i.e., weights vs. cardio) on muscle mass, fat and bodyweight. We can make inferences based on short-term responses to the exercises.
- If you have time, do one form of exercise in the morning and the other in the evening. Separate workout sessions by at least eight hours to maximize performance. The sequence is your choice.
- If you can only train once a day, choose the sequence according to your goals. People who want to emphasize endurance capacity should do cardio first, while those most interested in muscle mass and strength should lift weights first.
- It’s not clear which sequence causes the greatest fat loss. Doing cardio first results in the greatest increase in post-exercise metabolism. Weight training first increases hormones that speed fat use (growth hormone, epinephrine and norepinephrine).
- People who want to maximize muscle mass while losing fat should lift weights first and do cardio afterward.
No sequence is right for everyone. The most important thing is to include aerobic (cardio) and weight training in your exercise program. People usually don’t adhere to overly intense programs, so design a reasonable exercise regimen that you’ll do consistently. The old saying that “95 percent of success in life is showing up” is true for building muscle and strength, and cutting fat.






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