Cardio or Weights First?
Like many people, you probably face this constant conundrum when you walk into the gym: Should you do cardio before or after lifting weights?
The short answer is: It largely depends on your goals. Even if you don’t have a super-specific goal and want to train for better overall fitness, it’s important to combine cardio and strength wisely so you don’t overwork the same muscle groups. According to the American College of Sports Medicine, doing similar endurance and strength training back-to-back doesn’t allow for adequate recovery and could lead to fatigue and poor performance (thus increasing your injury risk), so you should carefully consider the type of exercises you’re doing.
If you have a specific strength goal—you’re looking to PR on your deadlifts or perfect the Turkish get-up—you definitely want to make the weight room your first stop. Here’s why: Your muscles are like a rubber band—it needs to be taut enough to restrict whatever it’s wrapped around If you take the rubber band and repeatedly pull it, it becomes too loose and unable to hold objects together. Your muscles work the same way.
Science backs up the weights-before-cardio plan. A 2016 study in the Journal of Strength and Conditioning Research recruited 11 healthy and fit men and examined their strength performance 10 minutes after a vigorous aerobic endurance workout—running on a treadmill at moderately-hard, very hard, or maximal intensity for between 20 and 45 minutes. The resistance exercises included the high pull, squat, bench press, deadlift, and push press. These strength exercises were performed for 3 sets of 6-10 reps at 70 to 80 percent of their one-rep max, with a three-minute rest interval between sets. Results showed that their performance on the strength moves was significantly compromised after the aerobic workouts. Participants performed fewer reps with the squats, in particular, and power was reduced for the high pull, squat, and bench press after doing most of the aerobic workouts.
Moreover, a November 2016 study in the European Journal of Sport Science had 30 recreationally fit men complete four different training protocols: strength training, strength followed by endurance training, endurance followed by strength training, and no training. The results suggest that performing endurance exercise prior to strength training results in impaired strength training performance, especially when lifting heavy. The study also showed that one-rep maximum performance was much better during strength training alone and during strength training before endurance than the opposite order.
Muscle cells store something called glycogen, which fuels muscular contractions, Glycogen is made from carbohydrates that your body breaks down into fuel. When your body converts glycogen into energy it becomes adenosine triphosphate, otherwise known as ATP. This process produces byproducts that can be recycled back into ATP and used as energy.
As mentioned, if you’re training for a big endurance event such as a triathlon or marathon, you generally want to use your energy for your cardio efforts and do them first.
Even if you’re not focusing on a cardio-specific goal, there are some instances when squeezing in some cardio before strength work can be beneficial—namely, as a warm-up. “Doing cardio before strength can be an effective strategy for ensuring the body is properly warmed up and prepared for the challenges of the strength exercises,” says McCall. Eric Sternlicht, Ph.D., associate professor of health sciences at Chapman University in Orange, CA, agrees: “Doing some light, steady-state cardio—about 10 minutes—before any intense effort or activity prepares the body for exercise or performance.”
If you have a specific strength-related goal, like deadlifting a certain amount of weight or learning a specific technique (such as an Olympic lift or kettlebell move), keeping it low-intensity is key. You should steer clear of HIIT and instead opt for steady-state cardio to limit the risk of fatigue affecting the strength workouts, says McCall. In fact, a 2013 study published in the Journal of Strength and Conditioning Research found that when exercisers did a low-intensity warm-up for 15 minutes, they were able to lift more weight in a one-rep max test on the leg press machine than those who did no warm-up, only warmed up for 5 minutes, or did a moderate-intensity warm-up of any length.
When it comes to weight loss, it doesn’t really matter which you do first—but strength trumps cardio, in terms of general importance.
Why? Strength training helps you increase or maintain lean body mass, which will burn more calories in the long run. The more muscle mass you have, the higher your resting metabolic rate which are the calories you burn long after your workout. That’s because it demands more on the anaerobic (oxygenless) energy pathways during exercise, which increases the need for oxygen post-workout.
That said, you shouldn’t skip cardio altogether. “Ultimately, you use more energy and expend more calories doing aerobic training because you’re moving consistently, whereas, with strength training, you may be using two-thirds of your time recovering, so adding some cardio can increase your overall calorie burn.
Fun fact: Regardless of whether you do cardio or weights first, there’s a handy word to describe a workout that combines both strength and cardio into one session: concurrent training. And, for the general public interested in using exercise to maintain healthy body weight, doing both cardio and strength in the same workout can be effective for expending energy and building muscle without any real risks.
Varying your workouts—whether you alternate doing cardio and strength first throughout the week, or stick to one for a couple of weeks and then switch—helps challenge your body in new ways, so you don’t hit a fitness plateau, says McCall.
And to make sure you don’t over-fatigue one muscle group, for example, consider pairing upper-body workouts with HIIT cardio days, and doing lower-intensity steady-state cardio on days when you’re doing lower-body strength moves.
The bottom line: You want to prioritize your workouts according to your goals. If you’re focused on lifting a certain amount of weight or mastering a new kettlebell exercise, then you should definitely hit the weight room first and supplement it with some steady-state cardio on the treadmill, rower or bike. On the other hand, if endurance is your goal, you should save your energy to go the distance and couple the stamina-building workouts with low-weight, high-volume strength training. And if you’re aiming to lose weight, you want to do a combination of strength and cardio—with a special emphasis on strength.