Why cardio last?

I've read several posts recently that talk about doing cardio after weight training. I was just wondering why it is suggested this way?

I like to run in the late evenings, and I find that, after a 20 or 30 minute easy jog, I have tons of energy and a strong desire to keep exercising. Couldn't I use a slow jog as my warm up, and then come in and lift?

I think it has something to do with the energy stores (glycogen) in the muscles. This energy is great for short bursts of exercise, like during weight lifting. If you do cardio first, it uses up these energy stores, so you won't lift as heavy as you could have. Of course, this may be totally wrong, but that is my understanding.

In this group, with its emphasis on maximizing a lifting workout, the advice generally is to lift first. If you go to rec.running, the general advice would be to run before doing any resistance training. If your doing both for general fitness, just do it the way that you enjoy most.

: would be to run before doing any resistance training. If your doing both : for general fitness, just do it the way that you enjoy most.

Hi James, thanks for the reply. Prejudices aside, assuming I am doing both for general fitness, in what order would you folks recommend if my goals are: to lose fat, build muscle, accustom myself to long (military) runs, and build endurance, in that order?

Thanks again.

Jogging as a warm-up is fine, what is being said is the cardio that brings on the pint of sweat and such.

Aerobic activity uses oxygen so you can use fats or glycogen as a fuel source. The faster you go, the more glycogen than fat you burn as the body turns to anaerobic to burn the glycogen since there is not enough oxygen (you still burn both, just the ratio switches).

Lifting is anaerobic from my understanding. You are lifting heavy weights to the point of muscular exaustion. The body can only use glycogen as the fuel on choice. This leads to that burn in the muscles (lactic acid build- up).

So if you do a cardio run, your body tends to use up all its glycogen store so that you have none left over for a serious workout with weigts. Lifting first burns the glycogen meaning the body will burn more fats for fuel as that is the most ready fuel available.

Also, if there is a long gap then lifting later in the day is no problem as the body has replenished its stores.

So lift to burn the sugers, then run to burn the grease.

Since you are trying to combine strength and endurance, one suggestion is to combine Bryce Lane's 'Have it All' routine with running. See: http://home.attbi.com/~joandbryce/it_all.htm

Do Bryce's routine on Mon, Tues, Thur., Fri. This will help with your strength and work capacity. Run on Wed, Sat and Sun., working toward adding distance.

Others may have better suggestions.

Prejudices aside, the correct order is to do quality training first, and 'base' runs last. You can do long slow training in a glycogen-depleted or fatigued state, but you need to be fresh for hard quality sessions (weightlifting or running).

So if you're just going for a long slow run, then there's nothing wrong with doing this after lifting. If it's a *really* long run (more than 90min) you may want to re-fuel before starting the run, but if it's 1 hour or less, you should be alright to just go and run after your weightlifting session (just get some water first)

On the other hand, it is probably not a good idea to do a hard track session just after lifting weights.

What I'd suggest is that if you're alternating hard and easy days, arrange your schedle so that your easy running days coincide with your weightlifting.

It's got nothing to do with prejudices. Weight training sessions will suffer if you tire your self out with an aerobics workout.

On the other hand, slow continuous training is not going to suffer as a result of lifting weights.

Lifting weights just before a race or even an interval training session would be foolish, but it has next to no effect on an easy run. I don't know why this is, but I do easy runs up to 1 hour long after weight lifting (usually without any refueling), and it doesn't make them any less easy.

i've tried a variety of cardio exercises, either as a warmup or as a 'light workout' before lifting

I have never EVER had a worthwhile weight workout after cardio.

I personally am a firm believer in breaking your workouts up so that you do your cardio and weights completely separate. i.e. cardio in the morning, lift weights in the afternoon.

so you don't notice that after a cardio workout, you are weaker and are forced to use less weight?

Science and physiology are not behind you on this.