You can gain strength and muscle while on a caloric deficit. It won’t be easy, but it can be done.
Donnelly JE, Sharp T, Houmard J, Carlson MG, Hill JO, Whatley J,E, Israel RG
Muscle hypertrophy with large-scale weight loss and resistance training.
Am J Clin Nutr. 1993 Oct;58(4):561-5.
This study put the participants on an 800-calorie-per-day liquid diet for 90 days.
The average weight loss over the 90 day period was 35lbs. Yet all subjects increased the cross sectional area of their muscle fibers significantly.
It appears that weight training can produce hypertrophy in skeletal muscle (and therefore increases in metabolism) during severe energy restriction and large-scale weight loss.
Hmmm…35lbs lost in 90 days with muscle GROWTH? That’s 2.73lbs per week fat lost and they didn’t lose ANY muscle.
Bryner RW, Ullrich IH, Sauers J, Donley D, Hornsby G, Kolar M, Yeater R.
Effects of resistance vs. aerobic training combined with an 800-calorie-liquid-diet on lean body mass and resting metabolic rate.
J Am Coll Nutr. 1999 Apr;18(2):115-21.
Aerobic group: 4 hours per week.
Resistance training group: 2-4 sets of 8-15 reps. 10 exercises, three times per week.
V02 max increased equally in both groups.
Both groups lost weight, the resistance training group lost significantly more fat and did not lose ANY LBM, even at only 800 calories per day.
The resistance training group actually increased metabolism compared to the aerobic group which decreased metabolism.
Only 800 calories per day and the resistance training group did not lose ANY muscle and actually increased metabolism. They also lost 15% of their bodyweight (and all fat) in 12 weeks. For a 180lber that would be 27lbs, a 200lber that would be 30lbs, and for a 250lber that would be 37.5lbs(more than 2lbs per week - all fat).
Looks like what “they say” is completely wrong.