Effects of Detraining (break from weight training)

October 14th, 2007 by Paul Johnson

After a month or two of heavy lifting, most bodybuilders will take a week or two off. Bodybuilding experts recommend it because it allows your body to recuperate it’s hormonal levels and help overcome plateaus. Bodybuilders often come back and break through previous plateaus within a few weeks, after a couple weeks off. I see taking breaks as a form of periodization, since you are essentially taking 2 steps back and changing your muscle adaption(or lack thereof), in order to get one step ahead.

Research studies on detraining:

I was curious to see what really happens after a break from weight training in experienced weightlifters. I decided to search through studies to get an answer.

An old study published in Med Sci Sports Exerc. 1993 Aug;25(8):929-35 where 12 powerlifters took 2 weeks off. Interesting enough strength did not decrease at significant levels, neither did their type 1(endurance) muscle fibers or fiber composition percent. However, the type 2(mainly responsbile for hypertrophy) decreased significantly (by 6.4%). Growth hormone levels increased 58.3%, testosterone increased 19.2%, and the testosterone to cortisol ratio 67.6% increased, whereas plasma cortisol -21.5% and creatine kinase enzyme levels -82.3% decreased.

A very recent study was published in J Strength Cond Res. 2007 Aug;21(3):768-75 done on 46 men. It compared completely stopping resistance for 4 weeks training to tapering it( reducing volume but intensity the same). This study was done immediately after 16 weeks of consistent resistance training. They found that the total break group had significant declines in strength and power, 9% and -17% respectively. The total break group also had increase in resting levels of IGF-1, a powerful hormone involved in muscle growth. The taper group had slight increases in strength and increase in IGFBP-3 resting levels. IGFBP-3 is the protein that binds to IGF-1 to deactivate it.

J Strength Cond Res. 2002 Aug;16(3):373-82 published a study of the effects of 6 weeks of detraining on recreationally trained men weightlifters. 9 were put in detraining group and 7 in resistance group during the 6 weeks. They were measured at week 3 and 6 for one rep max, power, and hormonal levels. The only effect was a significant decrease in power, but not in strength(in the one rep max). While the bench press strength increased in the restistance group there was no changes in any group for 1RM squat, body mass, percent body fat, or resting concentrations of growth hormone, follicle-stimulating hormone, luteinizing hormone, sex hormone-binding globulin, testosterone, cortisol, or adrenocorticotropin.

From the first two studies, we can see a large increase in anabolic hormones within the first weeks after the break. In the 3rd study there was no change in hormones or strength loss, however it was done on recreationally trained weightlifters. I believe the fact they were recreational, means they probably didn't workout regularly enough, to experience similiar strength loss and hormone rebound as the previous groups in the 2 studies. The first study was experienced power athletes and the 2nd worked out regularly for 4 months before the study.

These studies help point out that, taking a break will help recoup hormonal levels after even a couple weeks break from intense weight training routines. These breaks will help combat against overtraining caused by long term increases in cortisol and lowering of anabolic hormones such as Testosterone, GH, and IGF-1. They also help point out, that the ones who benefit the most from the break, are those who train intensely for months with consistency.

  1. cool dude on March 14th, 2008

    thats cool

  2. Ben on August 27th, 2009

    Just wanted to say I found this website and book marked it right away. Keep up the good work.

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  4. Chad on October 23rd, 2010

    When taking extended breaks like the ones recommended here, should cardio training be halted as well? In other words, should all training stop?