What should you do first, cardiovascular endurance exercise or weight lifting? Or does the exercise order even matter? The answer really depends on what you are trying to accomplish. Exercise order may matter if you are trying to achieve a specific goal, such as building strength, increasing endurance, or improving sports skills, or if you have an extremely high level of fitness already. But for the recreational athlete, it may simply come down to which order you prefer.﻿﻿

Exercise Order Recommendations

There isn't any special magic in exercise order, but some reasons it may matter have to do with the available energy for exercise, the causes of muscle fatigue, and the risk of injury during exercise. In general, the exercise you perform when you have adequate energy is performed at a higher intensity with more focus and efficiency. Exercise you perform when your energy supplies are low is less effective and more likely to result in injury.﻿﻿

Most recreational athletes can avoid this question altogether by doing cardio and weight training on different days. Another option is to do both endurance and strength training at the same time with interval training or circuit training routines that give a full-body workout in limited time.

Even though there is no magic in exercise order, some things seem to work better than others. If you have specific goals, use the following advice regarding exercise order.

If Your Goal Is Improving Overall Health

To improve overall health, it really doesn't matter if you lift weights first or do endurance training first.﻿﻿ In fact, you can do both at the same time with interval training or circuit training routines or you can alternate weightlifting and endurance days if you prefer.

If Your Goal Is Increasing Cardiovascular Endurance

In order to build and maintain cardiovascular endurance, you should perform endurance exercise first, when you have plenty of energy for long-distance exercise. ﻿﻿Add resistance exercises two to three times a week, either after or separate from the endurance work in order to develop muscular strength and reduce your risk of injury. Lifting prior to running is not recommended because you might increase your risk of injury during running due to muscle fatigue.﻿﻿

Refueling and staying hydrated is important when switching from cardio to resistance exercises in the same session. Cardio exercise will have depleted the fuel in your muscles (glycogen). A suggestion is to have half a bottle of sports drink to provide the muscle glycogen you will need to perform well in a weights workout.

If Your Goal Is Increasing Muscle Size and Strength

Two 2018 reviews of studies found that if your goal is to develop lower-body dynamic strength, doing your strength training before cardio may be more effective. These studies found no difference in either sequence for static lower-body strength, increasing muscle size, reducing body fat, or building aerobic capacity.﻿﻿

There has long been a belief, with some support from research, that endurance exercise has an interference effect for increasing muscle size (muscular hypertrophy).﻿﻿ The recommendation you will often see is to lift weights first when the body's main source of energy for muscle contraction (glycogen) is high. If you do a hard cardio workout before lifting, you deplete glycogen, which might make the workout ineffective. However, some current research reviews suggest the interference effect may be minor or absent.﻿﻿ If that is the case, the sequence does not matter.

If Your Goal Is Burning Calories for Fat Loss

The best way to lose body fat is to combine endurance exercise and resistance exercise. One powerful way to achieve this is through high-intensity interval training (HIIT), which combines short, high-intensity bursts interspersed with slow recovery phases.

In addition to increased fat burning and weight loss, research published in the Journal of Sports Science found HIIT increases the production of human growth hormone (HGH) by up to 450 percent and the effect can last up to 24 hours after a workout. HGH helps speed tissue repair, improve muscle and skin tone, and build lean muscle mass.﻿﻿

Adding HIIT to your workout can be done in a few different ways. You can alternate short but intense bursts of weight training (10 seconds to 3 minutes) with longer periods of light walking or marching in place, such as 30 seconds of weights followed by 2 to 3 minutes of light walking. Likewise, you can alternate between short, intense bursts of cardio and light weight training.

If Your Goal Is to Improve Specific Sports Skills

​If you are training for a specific sport, you'll need to design your training to accommodate the needs of that sport. Whether you do resistance or endurance training first depends on the requirements of the sport, your current level of fitness and your overall goals. If you aren't sure what is the best type of training for your sport, it's helpful to enlist the expertise of a coach or personal trainer.

Elite athletes perform a specific exercise order that encompasses days, weeks and months. Sport-specific training follows the competitive season and is carefully designed so that athletes will ​"peak" at the height of the season. Their training builds from a general foundation of overall fitness and becomes focused on specific skills, movements, and even psychological components in order to provide an edge over the competition.﻿﻿ These programs look like a pyramid and cover the entire spectrum of fitness (strength, endurance, flexibility, agility, psychology, etc...) over the course of a season.

If Your Goal Is to Exercise Consistently

In order to stick with exercise, it needs to fit into your daily routine and lifestyle. It also has to feel good to you. For this reason, it is helpful to pick the type of exercise, the order of exercise and the time of exercise according to what works best for your body. You may be naturally inclined to feel best if you do endurance exercise first and then do weights. You may also find that your body responds best when you lift weights at one time of the day and go for a run at another. It's OK to let your body, mood or interest determine when you exercise.