Though being sore from a grueling leg workout sounds like the worst case scenario before a cardio session, there are in fact many advantages to performing aerobic exercise the subsequent day after training the muscles of the lower body - or even just several hours after.
So long as the intensity and impact of the cardio session is appropriately maintained, there is little beyond some minor discomfort that poses a risk for exercisers going for a run the day after a leg workout.
Performing cardio after leg day is perfectly fine - and can even provide a number of benefits, such as improved recovery and reduced soreness to the muscles of the legs.
Now that we’ve established that you can indeed perform cardio after leg day, the question is instead how to go about doing so.
If the leg workout performed in the previous day was a particularly intense one, exercisers may wish to opt for lower impact forms of cardio that do not place excessive strain on the muscles of the lower body.
Conversely, having a light leg workout the day before can allow for a far more intense cardio session to take place - especially for athletes whose sport primarily revolves around aerobic exercise, rather than resistance training.
For exercisers seeking low impact and low muscular intensity forms of cardio, aerobic exercise machines like the stationary bike and elliptical are all excellent choices that will not interrupt recovery or result in chronic overuse injuries of the lower body.
On the opposite end, individuals who wish to focus more on cardio despite a leg workout being performed the previous day can make use of the stair climber machine, outdoor sprinting and high incline treadmill runs to rapidly boost their aerobic abilities or lose fat quickly.
Athletes or individuals that wish to focus on more than just cardiovascular system improvements can even make use of various cross training methods like plyometrics or drills, so long as the intensity is low enough to maintain proper leg muscle recovery.
All forms of cardiovascular exercise induce greater blood flow and a higher rate of heart beats per minute, thereby increasing venous deposition of nutrients, oxygen and various other materials to the muscles of the lower body.
Especially in cases where anabolic changes are taking place within a muscle group - this increased flow of blood can easily speed up the process of muscular growth and recovery.
In the case of performing cardiovascular exercise after a leg day workout, such benefits equate to the muscles of the lower body being ready for a workout sooner, and at a greater level of efficiency.
One must be careful to balance this out, however, as performing cardio workouts that only further stress the muscles of the legs will cancel out the greater recovery engendered from said cardio.
Similarly, an increase in blood flow throughout the body will also result in a reduction of inflammation and greater removal of lactic acid within muscle groups that have recently been recruited at high intensities.
At a larger scale, this will result in a reduced level of perceived soreness - especially of the lower body due to the greater amount of gross muscle mass found in the legs and lower posterior chain.
Light and low resistance forms of aerobic exercise are among the best ways to deal with delayed onset muscle soreness, as well as non-delayed muscle soreness from recent resistance training sessions.
Many seasoned competitive bodybuilders find that the muscles of their calves and abdomen respond particularly well to high volume recruitment - meaning exercise that involves a high tempo of repetitive motions, such as stair climbing or walking on a treadmill.
As such, for individuals that find that their calves are lagging behind the rest of their legs in terms of muscle mass - performing cardio at the end of their leg day, or even after can break such a plateau.
Performing a cardio workout after leg day doesn’t negate the usual benefits that come with proper aerobic exercise, such as greatly improved cardiovascular function, fat-burning potential and improved muscular endurance - all of which are a result of placing the appropriate level of training stimulus on the systems of the body.
One should understand that performing a cardio workout after leg day however, can result in their legs already being prematurely fatigued - affecting and limiting the intensity or length of their cardio workout, potentially influencing these aforementioned cardio benefits.
Resistance training can drain the glycogen out of the leg muscles, alongside also prematurely fatiguing them in a manner that reduces their maximum endurance during particularly long bouts of cardio.
As such, the best kind of cardio to employ after a leg day is not long and steady, but the sort of workout that is completed quickly and at varying levels of intensity.
In most cases, this takes the form of interval training - though other forms of cardio are also quite suitable, such as athletic drills or plyometric training.
Even if you’re capable of running or biking at an impressive level, it is quite important to temper expectations for the cardio workout that is to be performed after a leg day.
This is both to ensure that you don’t overexert yourself by training at nearly maximal level, as well as to keep in mind that the muscles of the legs are already fatigued from the previous training session, meaning that they cannot function at their greatest level just yet.
Instead, aim for anywhere between 50% to 70% of your maximum exertion level, as this is the ideal spot in which recovery is still enabled while retaining a sufficient level of intensity to challenge the body.
Not only are the muscles of the legs in need of recovery after a workout, but so too are the connective tissues and bones found in the lower portion of the body. This is simply a secondary effect of placing pressure and stress throughout the kinetic structure during resistance training, and is healed easily enough if given enough time.
However, placing further impacts on these structures by way of performing cardio after leg day can potentially be injurious - especially in the chronic sense, where conditions like tendonitis, stress fractures and dislocation are legitimate risks.
As such, if your leg day was quite intense and involved high amounts of resistance, it may be best to avoid high impact forms of cardio such as sprinting on hard surfaces or jump rope.
Individuals of different training disciplines will find that differing forms of cardio mesh far better with their goals than others, such as endurance athletes finding that longer form cardio days after a leg workout contribute more to performance in their sport.
For the most part, this distinction can be boiled down to whether the exerciser places more importance on their anaerobic performance instead of their aerobic performance.
For the former, performing lower impact and lower intensity cardio after leg day is preferable as it allows the leg muscles to recover more quickly and more efficiently, though foregoing the benefits of intense aerobic exercise as a tradeoff.
Likewise, athletes and exercisers that wish to work on their aerobic abilities will find that reducing the intensity of their leg workout prior to a cardio session will allow for a greater quality of training stimulus to be achieved in the latter workout.
If you’ve chosen to perform a cardio session after your leg day workout, you may find that your recovery time has increased due to both training sessions placing wear and tear on the various structures of the lower body.
While this can be mitigated by reducing total resistance and volume of either workout, there are also several methods that can help along the process of recovering so as to maximize your performance in any subsequent training session.
Making use of a foam roller after a cardio session allows the exerciser to double down on the improved blood flow benefits of aerobic exercise, while also simultaneously mechanically manipulating the fibers of their leg muscles - thereby improving mobility and reducing lactic acid buildup.
Foam rolling is an excellent method of accelerating recovery if the additional stress from cardio only further compounds upon that of a leg day workout.
Performing dynamic and passive stretching movements are another method of improving recovery, allowing a full range of motion to be maintained while simultaneously improving blood flow to the taxed muscles of the legs.
Though it is advised that exercisers perform stretching prior to a workout, there is also some benefit to be found in performing it after a workout as well - especially the sort of training that involves high amounts of repetitive movement, such as cardio.
Generally, performing a stretching drill after cardio following a leg day is one of the best methods of ensuring proper recovery is achieved - especially when combined with adequate macronutrient intake.
So, can you do cardio after leg day?
The answer is a resounding yes - so long as it is the right kind of cardio at a suitable level of intensity.
Thankfully, there are quite a few different forms of cardiovascular exercise, the majority of which can be modified to up or reduce the difficulty as is needed by the exerciser.
From uphill sprints to the elliptical machine, there is doubtless a kind of cardio that complements your previous leg day perfectly.
1. Schumann, M., Feuerbacher, J.F., Sünkeler, M. et al. Compatibility of Concurrent Aerobic and Strength Training for Skeletal Muscle Size and Function: An Updated Systematic Review and Meta-Analysis. Sports Med 52, 601–612 (2022). https://doi.org/10.1007/s40279-021-01587-7
2. Lee MJC, Ballantyne JK, Chagolla J, Hopkins WG, Fyfe JJ, et al. (2020) Order of same-day concurrent training influences some indices of power development, but not strength, lean mass, or aerobic fitness in healthy, moderately-active men after 9 weeks of training. PLOS ONE 15(5): e0233134. https://doi.org/10.1371/journal.pone.0233134