So I’m in the middle of doing my Personal Trainer course. It was a very interesting session tonight on the science behind exercise programming. The information in our text books comes from a range of referenced sources, including the current scientific research. So I thought that I would put a bit of the information here for consideration.
Before I started my PT course I focused mainly on concurrent training which means training to achieve multiple training goals at the same time. So you might do a cardio workout followed by a strength workout (or visa versa) as part of an hour long workout. Or you might do interval training combining cardio exercises and strength exercises (which i find very effective for certain things) now days I also have strength only sessions, cardio only sessions and some where I do one before the other.
But of concern is the question will aerobic exercise impare the resistance training workout performance and hence influence muscular strength and size?
Some research shows strength improvements to be impaired while others show no impairment from this type of training. For the recreational exerciser wanting general fitness concurrent training is generally fine (and can be beneficial as it takes less time).
But if you have more specific goals:
Muscle Strength or Endurance
If your main goal is to develop strength or muscle endurance then this should be performed before aerobic exercise and the aerobic exercise is likely to produce fatigue and limit the ability to work to your capability during the strength training thus impairing strength development. This does however appear to be specific to the muscles used ie. if you ran than trained your legs your leg muscles will be compromised….if you used the bike and then trained your arms the affects may be not so bad.
“Forty minutes of preceding aerobic exercise can compromise strength performance for up to 8 hours.”
“For the client who wants muscle strength and/or size, evidence suggests that allowing 4-6 hours between cardio and strength training sessions avoids anabolic disruption…. Hence, a client could go for a run at 7am and then lift weights at the gym at 1pm or vice versa.”
If cardio fitness is the key goal this should be done first in order to put the most effort and gain the most benefits.
The bottom line appears to be that concurrent training is fine for most fitness goals and can be adjusted to suit your needs, however if you are really looking for muscle gains it is best to keep cardio and weight training separate for the majority of your training sessions.
I will be adding a post on the different types of muscular training (strength, endurance and hypertrophy (increase in size) soon!