Nutrition and health

Objectives:
Does strength training improve total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL), high-density lipoprotein (HDL), C-reactive protein (CRP) and adiponectin levels of adults?

Study design:
This review article included clinical trials up to May 2017.

Results and conclusions:
The investigators found strength training significantly reduced total cholesterol levels [ES = -0.399, p  0.001]. 

The investigators found strength training significantly reduced triglycerides levels [ES = -0.204, p = 0.002]. 

The investigators found strength training significantly reduced LDL cholesterol levels [ES = -0.451, p  0.001]. 

The investigators found strength training significantly reduced CRP levels [ES = -0.542, p = 0.01]. 

The investigators found strength training significantly increased HDL cholesterol levels [ES = 0.363, p  0.001]. 

The investigators found strength training significantly increased adiponectin levels [ES = 1.105, p = 0.01]. 

The investigators concluded strength training promotes decreases in total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL) (also called bad cholesterol), C-reactive protein (CRP) levels and increases high-density lipoprotein (HDL) (also called good cholesterol) and adiponectin levels of adults. Thus, progressive strength training could be a potential therapeutic option for improving abnormalities in lipid and inflammatory outcomes in adults.

Original title:
Effect of Strength Training on Lipid and Inflammatory Outcomes: Systematic Review With Meta-Analysis and Meta-Regression by Costa RR, Buttelli ACK, […], Kruel LFM.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31023184

Additional information of El Mondo:
Find here more information/studies cholesterol and sport nutrition.

Objectives:
Creatine supplements are intended to improve performance, but there are indications that it can overwhelm liver and kidney functions, reduce the quality of life and increase mortality. Therefore, this review article has been conducted.

Does creatine supplementation increase risk of renal damage?

Study design:
This review article included 15 studies in the qualitative analysis and 6 studies in the quantitative analysis.

Results and conclusions:
The investigators found creatine supplementation did not significantly increase serum creatinine levels [standardized mean difference = 0.48, 95% CI = 0.24-0.73, p = 0.001, I2 = 22%].

The investigators found creatine supplementation did not significantly increase plasma urea values [standardized mean difference = 1.10, 95% CI = 0.34-1.85, p = 0.004, I2 = 28%].
The investigators concluded that creatine supplementation does not induce renal damage in the studied amounts and durations.

Original title:
Effects of Creatine Supplementation on Renal Function: A Systematic Review and Meta-Analysis by de Souza ESA, Pertille A, […], de Oliveira JJ.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31375416

Additional information of El Mondo:
Find here more information/studies on kidney disease and creatine.

Objectives:
Studies have shown that creatine supplementation increases intramuscular creatine concentrations, favoring the energy system of phosphagens, which may help explain the observed improvements in high-intensity exercise performance. However, research on physical performance in soccer has shown controversial results, in part because the energy system used is not taken into account. Therefore, this review article (meta-analysis) has been conducted.

Does creatine supplementation improve physical performance in soccer players?

Study design:
This review article included 9 RCTs with a total sample of 168 soccer players (118 males, 50 females) with an average age of 20.3 ± 2.0 years (from 15 to 30 years, as an average for the experimental sample).

The meta-analysis was performed using the random effects model and pooled standardized mean differences (SMD) (Hedges's g).

Results and conclusions:
The investigators found that creatine supplementation did not present beneficial effects on aerobic performance tests [SMD = -0.05, 95% CI = -0.37 to 0.28, p = 0.78] and phosphagen metabolism performance tests (strength, single jump, single sprint and agility tests: SMD = 0.21, 95% CI = -0.03 to 0.45, p = 0.08].

The investigators found, however, creatine supplementation showed beneficial effects on anaerobic performance tests [SMD = 1.23, 95% CI = 0.55 to 1.91, p 0.001].
Concretely, creatine supplementation demonstrated a large and significant effect on Wingate test performance [SMD = 2.26, 95% CI = 1.40 to 3.11, p 0.001].

The investigators concluded creatine supplementation with a loading dose of 20-30 g/day, divided 3-4 times per day, ingested for 6 to 7 days and followed by 5 g/day for 9 weeks or with a low dose of 3 mg/kg/day for 14 days presents positive effects on improving physical performance tests related to anaerobic metabolism, especially anaerobic power, in soccer players.

Original title:
Effects of Creatine Supplementation on Athletic Performance in Soccer Players: A Systematic Review and Meta-Analysis by Mielgo-Ayuso J, Calleja-Gonzalez J, […], Fernández-Lázaro D.

Link:
https://www.mdpi.com/2072-6643/11/4/757/htm

Additional information of El Mondo:
Find here more information/studies about sport nutrition and creatine.