The Difference Between Cardio Before and After Resistance Training
Cardio and resistance training are both very important aspects of a fitness routine. But a common thought people experience with working out is whether to do cardio BEFORE or AFTER lifting weights. Here is a break down of the difference between doing cardio before or after weight training:

BEFORE: When cardio is done before weight training, the body begins using energy in the form of glucose (burning glucose for energy). This can lead to lower energy levels when resistance training begins. This can cause someone to feel fatigued. This will also create a more significant cardio impact during resistance training as lifting can become more challenging because the body is already fatigued, thus having the cardiorespiratory system working harder. This will create a weight training session that is more challenging for the heart, which can have positive impacts for the cardiorespiratory system (heart health). It is resistance training while receiving a greater cardio workout.

This can help with improving cardio and make weight training sessions more challenging. This is an ideal approach for people focusing on improving cardio and endurance. The drawback is that lifting potential may decrease as each lift can become more challenging due to lower energy levels. This can impact muscle mass if the intensity/weight is reduced because the individual does not have enough energy or lifting power to complete the exercise.
AFTER: When cardio is completed after weight training, an individual will increase their lifting potential because the body has more energy. This can increase muscle mass as the intensity (weight being used) or volume (repetitions) of the exercise is increased. With more muscle mass, the metabolism will increase and burn more fat. This is an ideal approach for anyone looking to get stronger, increase muscle mass, and burn more fat.

Summary
The KEY difference between training cardio before or after a weight training session is that BEFORE will train cardio more aggressively throughout a weight training session, that will lead to better endurance. AFTER will have an impact of training muscles with more intensity that can lead to more muscle mass and burning more fat. Cardio is a vital component of fitness and should always be included in training sessions.