Can Losing Weight Affect a Decrease in Bench Press Strength?

When you're working hard to sculpt your best physique, dropping a few pounds may be necessary to showcase your hard-earned results. But be careful that the weight you're shedding comes from fat and not muscle, or your performance may suffer. You can avoid the loss of lean mass and preserve your strength by adhering to a few simple guidelines.

  1. Muscle versus Fat

    • When losing weight, it is encouraging to see the numbers on the scale go down. But if you want to avoid a decrease in lean muscle mass and an associated loss in strength, a weight scale should not be your only assessment tool. Body composition is a ratio of fat mass to total body weight. Your fat-free mass is made up of muscle, bone and other body tissues that exclude fat. When losing weight, focus on maintaining or increasing your fat-free mass. You can have your body composition analyzed by a fitness or athletic professional using a skin-fold caliper or a displacement tank that measures your hydrostatic weight. Beware of handheld bio-electrical impedance devices, which can have a broad margin of error.

    Nutritional Guidelines to Preserve Muscle

    • Nutrition plays an important role in weight loss, and eating the right foods can influence whether you lose muscle or fat. A 2009 paper presented at the 110th Abbott Nutrition Research Conference pointed out that carbohydrate-restricted diets with high protein intake produced greater weight loss and preserved lean muscle mass better than low-fat diets. A 2012 review published in the "Journal of the International Society of Sports Nutrition" noted that increasing your dietary protein has favorable effects on muscle and strength during resistance training.

    Training to Preserve Muscle

    • To avoid a decrease in strength, it is important to maintain a regular training schedule during weight loss. An overly restrictive diet can cause you to feel lethargic and lead to a reduction in training. Some people are under the false impression that they should lay off weight training altogether and focus on cardio while losing weight. But a 2010 study of world-class kayakers published in "Medicine and Science in Sports and Exercise" found that a cessation in training over 43 weeks resulted in large decreases in maximal strength. Finding a balance between reducing calories and ingesting enough energy to continue your training regimen is key to maintaining strength and lean mass.

    Rate of Weight Loss and Performance

    • The rate at which you lose weight may also impact your strength performance. A 2011 study of elite athletes published in the "International Journal of Nutrition and Exercise Metabolism" found that a weekly weight loss of 0.7 percent of total body weight was optimal for preserving lean mass and strength. However, another study performed in the same year and published in the same journal found that after a period of 12 months, the initial rate of weight loss had little influence on long-term markers of body composition and athletic performance.