1.
Negative Consequences of Low Energy Availability in Natural Male Bodybuilding: A Review.
Fagerberg, P
International journal of sport nutrition and exercise metabolism. 2018;(4):385-402
Abstract
Energy availability (EA) is a scientific concept describing how much energy is available for basic metabolic functions such as reproduction, immunity, and skeletal homeostasis. Carefully controlled studies on women have shown pathological effects of EA < 30 kcal/kg fat-free mass (FFM), and this state has been labeled low EA (LEA). Bodybuilding is a sport in which athletes compete to show muscular definition, symmetry, and low body fat (BF). The process of contest preparation in bodybuilding includes months of underfeeding, thus increasing the risk of LEA and its negative health consequences. As no well-controlled studies have been conducted in natural male bodybuilders on effects of LEA, the aim of this review was to summarize what can be extrapolated from previous relevant research findings in which EA can be calculated. The reviewed literature indicates that a prolonged EA < 25 kcal/kg FFM results in muscle loss, hormonal imbalances, psychological problems, and negatively affects the cardiovascular system when approaching the lower limits of BF (∼4%-5%) among males. Case studies on natural male bodybuilders who prepare for contest show muscle loss (>40% of total weight loss) with EA < 20 kcal/kg FFM, and in the study with the lowest observed BF (∼4 kg), major mood disturbance and hormonal imbalances co-occurred. Studies also underline the problem of BF overshoot during refeeding after extremes of LEA among males. A more tempered approach (EA > 25 kcal/kg FFM) might result in less muscle loss among natural male bodybuilders who prepare for contest, but more research is needed.
2.
Effect of resistance training on immunological parameters of healthy elderly women.
Raso, V, Benard, G, DA Silva Duarte, AJ, Natale, VM
Medicine and science in sports and exercise. 2007;(12):2152-9
Abstract
PURPOSE To determine the effect of a 12-month moderate resistance training program on phenotypic and functional immunological parameters of previously sedentary, clinically healthy, elderly women. METHODS A total of 42 clinically healthy, sedentary females (aged 60-77 yr old) were randomly assigned to either a moderate-intensity resistance training program or a control group during a 12-month longitudinal, randomized, controlled, intervention study. Resistance training program consisted of three sets of 12 repetitions at 54.9 +/- 2.4% 1RM for five different exercises performed three times per week during 12 months. Natural killer cell cytotoxic activity (NKCA), lymphoproliferative response to the mitogen phytohemaglutinin (PHA), and quantification of the lymphocytes (CD3, CD3CD19, CD56) and subpopulations (CD4, CD8, CD56, CD56) as well as cellular expression molecules (CD25, CD28, CD45RA, CD45RO, CD69, CD95, HLA-DR) were determined by immunological assays. RESULTS The experimental group increased muscle strength in 44% and 48% after 6 and 12 months, respectively (P < 0.05). There were no statistically significant differences between the groups or according to the time for quantitative (CD3, CD3CD19, CD56, CD4, CD8, CD45RA, CD45RO, CD56, CD56, CD95, CD28, CD25, CD69, HLA-DR) and functional immunological parameters (natural killer cell cytotoxic activity and lymphoproliferative response). CONCLUSION A 12-month moderate resistance training program increases muscle strength, but it does not change immune phenotypic and functional parameters of previously sedentary, clinically healthy, elderly women.