Whether you should run before or after lifting weights depends largely on your personal fitness goals, as well as how your body responds to different types of exercise. There is no universal answer, but understanding the effects of cardio and strength training individually and in combination can help you make an informed decision.
If your primary goal is to build strength or muscle mass, it is generally better to lift weights first and then do cardio afterward. Weight training requires maximal effort and energy, so doing it first ensures you can perform at your best and lift heavier, which is crucial for muscle growth and strength gains. Research suggests that doing cardio after weight training may also promote fat burning more effectively. This is because after weight training, your body’s glycogen stores are depleted, so when you do cardio next, your body is more likely to use stored fat for energy, potentially enhancing fat loss[2][6].
On the other hand, if your main goal is to improve cardiovascular endurance, such as training for a marathon or increasing aerobic capacity, it makes sense to do cardio first. Starting with running or other aerobic exercise allows you to focus your energy on improving stamina and cardiovascular fitness without being fatigued from lifting weights. This approach helps you train your aerobic system more effectively[2].
From a hormonal and metabolic perspective, cardio and strength training affect the body differently. Cardio exercise stimulates a greater increase in the hormone FGF21, which has positive effects on metabolism, while strength training does not produce the same hormonal response. This difference highlights that the two types of exercise have distinct benefits and mechanisms in the body[1].
Regarding performance and recovery, eating before or after exercise can influence how you feel and perform, but the timing of cardio relative to weights is more about your goals than nutrition timing. For workouts longer than an hour, eating beforehand generally improves performance, but for shorter sessions, it may not matter much. Fasted cardio (doing cardio on an empty stomach) does not appear to provide significant advantages for fat loss or muscle gain compared to fed cardio, and it can sometimes cause discomfort like headaches or nausea in some people[3][7].
It is also important to consider that combining cardio and weight training in the same session can lead to some interference effects, where endurance training might blunt some strength and muscle gains if not programmed carefully. However, this interference is usually minimal for most recreational exercisers and can be managed by adjusting intensity, duration, and order of exercises[6].
In summary, the decision to run before or after lifting weights should be guided by your fitness objectives:
– For **strength and muscle building**, lift weights first, then do cardio to maximize strength performance and enhance fat burning.
– For **cardiovascular endurance**, do cardio first to prioritize aerobic training.
– For **general fitness or weight loss**, the order is less critical; consistency and overall exercise volume matter more.
Listening to your body and adjusting based on how you feel during workouts is also key. Some people may find they perform better or recover faster with one order over the other. Experimenting with both approaches can help you find what works best for you.
Sources:
[1] University of Copenhagen study on cardio and strength training hormonal effects
[2] Powermax Fitness article on cardio vs weights order for fat loss and strength
[3] Futura Sciences on fasted cardio and workout nutrition timing
[6] Vocal Media on cardio or weights for optimal fitness
[7] The Independent on exercising before breakfast and fat loss
