What Comes First: Cardio or Strength Training?
One of the longest-running arguments in the world of health and fitness is whether it's best to lift weights before or after cardio.
Passions run high on both sides of the debate, with claims ranging from "weights first or you'll spend your whole life weak," to "cardio first or your heart's going to explode."
But what does the science have to say about all of this? Let's take a look.
For losing weight... weights first
One 2007 study 1 from the University of Tokyo found that lifting weights before cardio significantly boosted fat burning during the later cardio session, but only if the break between the weight and cardio sessions was kept to around 20 minutes.
The study didn't, however, look at the effects of doing cardio before a weight training session ---it only compared the effects of cardio by itself against weights followed by cardio.
Nonetheless, it's obvious that doing cardio after weight lifting is better for fat loss than just doing cardio solo.
A similar 2009 study 2 published in the European Journal of Applied Physiology found the same fat-burning benefits for doing resistance training before cardio, and also noted that high-intensity weight training before the cardio session had an even stronger fat burning effect.
Finally, a 2015 study 3 published in the journal Science and Sports actually compared the fat-loss effects of workouts which included cardio before weights vs. weights before cardio, and concluded that weights before cardio was likely better for fat loss.
The research seems clear enough; if you want to burn fat, do your weight training before your cardio.
For building strength... weights first
Ask most strength gurus whether it's a good idea to do cardio before lifting, and you can expect a full-on tirade about how the cardio will leave you drained and performing like a little child in the weights room. The research seems to more-or-less back that up.
One 2009 study 4 done on world-class kayakers found that when they performed resistance training before cardio --- or after leaving a 6-hour window between types of training to allow for adequate rest --- they significantly improved their muscular strength and power, and even their aerobic capacity.
Another 2014 study 5 published in the European Journal of Applied Physiology, comparing weights before cardio to cardio before weights, found about the same outcomes for both groups, in terms of strength development after 24 weeks of training. At the same time, though, the study found that the cardio-first group suffered more fatigue, and reduced testosterone levels, at least in the early stages.
Finally, a 2003 study 6 found that performing aerobic exercise before a resistance training session significantly reduced the number of reps subjects could do in the weights room with the muscle groups worked during cardio.
For cardiovascular conditioning... cardio first
If your main focus is cardio conditioning, it might be a good idea to do your cardio training first.
A 2005 study 7 published in the British Journal of Sports Medicine found that doing circuit resistance training after a cardio session resulted in significantly improved aerobic capacity than doing things the other way around.
Another study8 from 2011, focusing on elderly subjects, found that weight training before cardio led to a significantly improved VO2 max, with the reason likely being that VO2 max in elderly subjects is inhibited by age-related losses in strength and muscle.
For young trainees looking for maximum cardio conditioning, cardio comes first. For elderly trainees, cardio should follow weights.
For improving health... it depends (but probably weights first)
Improving overall health isn't a simple one-size-fits-all thing. For one, both strength and cardio conditioning as well as hormone balance and weight, all contribute massively to overall good health.
For elderly trainees, it seems that doing resistance training first is ideal. For those of all ages who are lacking in the strength department, or who are carrying too much weight, doing weight training first is, again, ideal.
For younger trainees who desperately need to get their cardio up to scratch? Doing cardio first is likely the best policy.
Interestingly enough, research 9 from the American Diabetes Association has also found that weight training before cardio is likely the best policy for people with diabetes, as this training setup seems to ensure steadier blood sugar levels throughout the entire training session.
[1] https://www.ncbi.nlm.nih.gov/pubmed/17277595
[2] https://www.ncbi.nlm.nih.gov/pubmed/19504118
[3] http://www.sciencedirect.com/science/article/pii/S076515971500146X
[4] https://www.ncbi.nlm.nih.gov/pubmed/19396614
[5] https://www.ncbi.nlm.nih.gov/pubmed/24435710
[6] https://www.ncbi.nlm.nih.gov/pubmed/14636098
[7] https://www.ncbi.nlm.nih.gov/pubmed/16046343
[8] https://www.ncbi.nlm.nih.gov/pubmed/21311345
[9] http://care.diabetesjournals.org/content/early/2012/02/22/dc11-1844.short