Although it can often come down to energy levels and personal preference, picking the right order for cardio and lifting weight, also called resistance training, might result in more than just tired muscles or a shorter-than-normal session on the elliptical machine. Even though physical performance may not suffer much whichever way you decide to exercise, saving your cardio for after you’ve lifted weight could give you an important and hidden long-term health benefit.
Intense weight training can drain your muscles of energy called glycogen, leaving you too tired to take part in any aerobic activity. Conversely, if you perform intense cardio exercise first, you may find that you lack the energy to lift weights. However, some light-to-moderate aerobic exercise before you lift should not affect your resistance training too much and can provide you with a good warm-up.
Impact on Muscles
A scientific study published in "Medicine and Science in Sports and Exercise" found that light-to-moderate aerobic exercise before lifting weights had little effect on the muscles themselves or how they contracted. Further, performing light-to-moderate resistance training first has no effect on your ability to adequately perform aerobic exercise after lifting weight. Light-to-moderate cardio exercise before or after lifting weights should have no effect on your physical ability to adequately perform either.
A 2007 study in Japan published in the "Journal of Applied Physiology" found that arteries opened up and blood flow increased when aerobic exercise was carried out after weight training. Further, a study in 2005 published in the "Journal of Applied Physiology" found that resistance training can cause a reduction in the elastic properties of arteries, causing blood flow to become restricted, leading to an increase in blood pressure levels. Taking the information offered in these studies into account, it appears that, for long-term vascular health at least, it’s better to perform cardio after lifting weights.
Because a mix of both aerobic exercise and weight training every week is recommended to ensure a healthy and fit body, a split routine can be of benefit. Try lifting weights for 20 to 30 minutes on Monday, Wednesday and Friday while taking part in aerobic exercise for the same duration on Tuesday and Thursday to help keep the vascular system healthy. The weekend can be used to rest or you can fit in another session of aerobic exercise on either Saturday or Sunday.