New Research compares concurrent training (lifting & cardio) with high intensity endurance training (HIIT) versus moderate intensity endurance training (LISS & MOD)

Combining weightlifting with cardiovascular activity can be very beneficial when considering one’s overall health and longevity. Not only does this benefit body composition, heart health, and overall fitness, but it’s a great way to increase energy expenditure during a weight loss diet.

But what if your goals are to maximize strength and size gains from weight lifting? Certain forms of cardio may be better or worse to implement if maximizing strength and hypertrophy is your main goal.

There are several types of cardio we can look at, but here are the most common;

HIIT: High-intensity interval training is an approach to cardiovascular activity using an alternating strategy of intense bursts of effort with less intense recovery periods.

LISS: Low-intensity steady-state cardio is an approach to cardiovascular activity in which you perform long bouts of aerobic activity such as biking, running, walking, or elliptical, among other modalities. 
MOD: Moderately intense interval training is similar to that of HIIT, just with less intense effort required. The purpose is to elicit similar results to that of HIIT, however, without the extreme fatigue most commonly associated with HIIT.

This latest study set out to see whether high intensity intervals or moderate intensity steady state cardio interfered more with hypertrophy and strength gains when combined with strength training.

Research Findings

High and moderate intensity cardio interfered with strength gains and hypertrophy to a similar degree – the subjects made gains, but smaller gains than the folks only doing strength training.

When looking at both results and effort invested, moderate intensity cardio came out on top. The participants consistently rated high intensity interval training as consistently more challenging (duh) than moderate intensity cardio, even though time and workload were equated.

Important Takeaways

Plain and simply, If you want to maximize rates of strength gains, your best bet is to limit cardio.

The magnitude of interference that cardio has on strength training results seems to depend of the frequency, volume and mode of cardio you do, with lower frequencies, lower volumes, and lower impact forms of cardio leading to a small interference

If you want to include cardio for health reasons or to increase your daily energy expenditure, keeping most of your cardio training bouts low to moderate intensity is probably most ideal.

Because moderate to low intensity cardio is rated to be easier than high intensity intervals per unit of workload, it may be the better choice as it won’t interfere with your ability to hit the weights hard during your net bout of strength training.

From other research in this area, it seems that spacing cardiovascular exercise away from weight lifting will help limit interferences and is recommended.

This means that weight training in the morning, and then doing your cardio in the evening – or vice versa.