It’s a common question asked throughout a lot of forums in the interwebz: “I’m looking to do [XYZ goals], should I do cardio first or strength training first? and if so, how much of each?”
As with many questions, this has a lot of “what if” scenarios attached to it, but the basic premise of why the question is being asked comes down to whether doing cardio first will burn more calories than after, whether doing cardio will reduce strength for weight training, and whether one is better than another and should be prioritized in daily training for specific goals like losing fat or gaining muscle.
All good questions, and the answer to all could be “yes, no, or maybe” depending on the application. What we have to consider is the volume and intensity of cardio performed, volume and intensity of resistance training performed, whether there’s a “point of limitation” to using one modality over another (ie, 20 minutes of cardio = bueno, but does 30 minutes = no bueno in terms of weight you can lift?), and also if there’s a best time to do each (split training versus one right after the other).
Let’s break it down into what happens with each of the main scenarios: cardio before strength vs. strength before cardio.
Cardio training provides some specific benefits that can parlay over to strength training: increased blood volume, nutrient delivery and waste removal, neuromuscular excitation, vasodilation, and upregulation of energetic pathways that can provide more of the molecules used in muscle contractions (creatine phosphate, ATP, and other Krebs cycle products and byproducts).
The benefits to warm ups on performance have been studied relatively exhaustively, and seem to be rather universally beneficial, except for one that would consist entirely of static stretching. Soligard et al even showed a significant reduction in lower limb injuries among female soccer players with the inclusion of a dynamic warm up before practices and games.
For run performance, there’s definitely a connection between doing some hard endurance training followed by circuit-style strength training. Chtara et al showed a benefit to Endurance + Strength in terms of 4km run performance over Strength + Endurance training concurrently. In military studies, resistance training following endurance training uniformly (see what I did there?) improved all tested parameters of strength and endurance compared to either endurance alone or strength alone.
Benefits to sport and to performance training that involves an aerobic or anaerobic component seem to be significantly benefitted by involving cardio before weight training, and to a somewhat greater amount than weight training before cardio.
However, this becomes somewhat muddied when it comes to performance goals of maximum strength. A landmark study by Hickson back in the 80s showed combining strength training with endurance didn’t produce strength benefits to the same degree as strength alone in terms of maximum strength output. The belief that endurance training “interferes” with the ability to gain strength is somewhat paradoxical, and isn’t supported by training programs like common strongman and powerlifting camps that involve conditioning elements after the max strength work. It’s also not known if there’s a gender difference in this application, but it seems to be a consideration.
If you’re doing 2-a-day training sessions with cardio in the morning and weights in the afternoon or evening, there’s evidence to show cardio performed 4 and 8 hours prior to weight training caused a decrease in work output on bench press and leg press at 75% of 1RM, in some instances by up to 25% compared to controls or those allowed to recover for a full 24 hours, and the most stark declines in weight training performance showing in those assigned to the high intensity interval group compared to the sub-max group. This is a pretty substantial difference, and if your goal is getting Jacked AF, a 25% decrease in weight training volume could be an impediment.
A big consideration that doesn’t seem to have been studied is the volume of cardio performed prior to strength training and it’s effects on performance, either negatively or positively. In my observations, people seem to perform better when made to do a short bout of aerobic work prior to strength work. This duration could be anywhere from 3-20 minutes depending on the relative trained status of the individual (more well-trained seem to require longer durations to warm up effectively and are more well conditioned to tolerate such volumes).
If you’re looking to maximize strength training benefits, a 10-20 minute cardio “warm up” prior to weight training seems to be positively beneficial, whereas longer durations seem to reduce force output and work capacity during the sessions (45+ minutes). Involving a small number of anaerobic intervals during this time seems to be additive as well, as long as they’re not to exhaustion.
The timing prior to weight training is also important. Performing cardio training as immediately to strength training produces better results in terms of weights lifted and work volume performed compared to longer breaks (seriously, check Insta and FB later).
So if you’re goals are to lift all the weights, gain muscle as much as possible, and be a straight up bad ass with a barbell, a reasonable outline would be to do 10-20 minutes with 2-4 HIIT intervals before your strength work.
If weight loss is a goal, concurrent cardio and strength training seems to produce the best benefits, but no studies to date that I was able to find have shown a specific benefit to performing cardio or strength training first in a workout (if you have a reference, please let me know!) in work-matched studies. Therefore it could be considered that which ever the individual enjoys doing to produce the caloric burn, while still producing the output would be considered a good way to go.
Maybe they just want to get after the weights hard and then stare into the ether for a half hour to recover from the mind-numbingly intense AMRAP deadlifts. Or they want to feel like a walking lake prior to getting under the squat bar from a superb sweatiness. To each their own, but note that longer duration cardio prior to strength training shows a bit of a deleterious effect on max strength, so in that case splitting cardio to sandwich the weight training may be the better option. A little before and a little after would still equate to the same work output, without interfering in the strength training.
So let’s break down what to do when**
Max Strength –> Strength first
Max Muscle –> Strength first
Fat Loss –> which ever allows you to get the same work output
Endurance performance –> Cardio first
Speed, sport development —> cardio first
**All would benefit from a 10-20 minute warm up with a few non-exhaustive intervals thrown in.
It’s important to note as well that training calendars change and primary goals shift within the individual all the time, so these aren’t constant elements, but can be adjusted based on what phase of training an individual is in. For instance, a bodybuilder may spend 80% of their training calendar working on gaining muscle, therefore prioritizing strength first in their workouts, but then during contest prep phases prioritize cardio training over strength. A cyclist may prioritize cardio first for most of their calendar, but then shift to strength training during their off season. Don’t stick to one mode all the time, play with it and see what works best for you.