It depends on body-fat levels. Someoe with some bodyfat to spare need not worry about gaining weight, it's the toothpicks who starve endlessly who shouldn't be deathly afraid of it. Keep the body-fat low and things work out. Raptors approach is better for people under 8% body-fat and he's exactly right, each cycle of weight results in greater relative strength than would be there had the person stayed weight stable. Even the O lifters in light weight classes cycle their weight. 3-5 kilos up, 3 kilos down etc.
^^^
This!
I would also add that this 'critical' bodyfat percentage depends on the person.
I also use raptor's approach ( actually it's your approach Kelly ,
http://www.higher-faster-sports.com/relativestrengthmyth.html ).
My bodyfat is nowhere near 8% , but it never was too. For me ( given my age and built ) 15% is my 'normal' bodyfat.
What i do is cycle between ~185 and ~200lbs. At my first try beginning bodyfat was ~15% and final ~20%. Even like that cycles still worked , you can see them all well documented in my journals.
Now, after 3 or 4 cycles the last 1,5 years i am at ~197/15% , so this is an extra improvement , the cycles are not identical , every time i reach the bulk peak ( which is the same weight ) i am always a bit stronger and with a bit less bodyfat. In the same way , at the leaning peak i am always relatively stronger than last time.
Here's my PRs log showing it happen:
LEAN:
June 2009 : DLRVJ PR : 33'' , getting consistently wrist(8'') to 10' rim on 2 different gyms , BW ~180.
BULK:
12 October 2009 : SVJ PR : 27'' , BW ~192
23 October 2009 : SVJ PR : 27,5'' , BW ~193
LEAN:
6 January 2010 : SVJ PR : 28,5'' , BW ~186
22 March 2010 : DLRVJ 32,5'' , no PR but i havent jumped above 32'' From June 2009 ( ! ) , BW ~187
BULK:
19 April 2010 : SQUAT PR : 3x264 , MSEM , ~1min rest between reps , BW ~192
27 April 2010 : DLRVJ 33'' , PR tie.
20 May 2010 : MSEM SQUAT PR : 2x1x275 , BW ~194.
6 June 2010 : DLRVJ 33'' , PR tie.
12 June 2010 : DLRVJ PR , 33,5''
15 June 2010 : SQUAT PR : 4x275 , BW ~198.
20 June 2010 : DLRVJ PR , 34''
LEAN:
25 June 2010 : SQUAT PR : 3x297 , BW ~196.
26 July 2010 : SVJ PR : 29'' , DLRVJ PR : 34,5'' , BW ~190
BULK:
Happening now , SVJ ~29, RVJ ~33,5 , BW ~197