Nutrition and health

Objectives:
Is there a difference between high-load (≥70 of 1RM) and low-load (70 of 1RM) resistance training (RT) on femoral neck and lumbar spine bone mineral density (BMD) in middle-aged and older people?

Study design:
This review article included 6 RCTs.

Results and conclusions:
The investigators found the meta-analysis revealed no difference in femoral neck bone mineral density [MD = 0.00 g/cm², 95% CI = -0.01 to 0.01, p = 0.63, I2 = 47%, p = 0.07] and lumbar spine bone mineral density [MD = 0.01 g/cm², 95% CI = -0.00 to 0.02, p = 0.12, I2 = 59%, p = 0.02] between high-load (≥70 of 1RM) resistance training group and low-load (70 of 1RM) resistance training group. 

The investigators found subgroup analysis revealed a significant effect of high-load resistance training on femoral neck bone mineral density when participants presented normal bone mineral density values [MD = 0.01 g/cm², 95% CI = 0.00 to 0.02, p = 0.04] and on interventions lasting up to 6 months [MD = 0.01 g/cm², 95% CI = 0.00 to 0.02, p = 0.03].

The investigators concluded both high-load (≥70 of 1RM) and low-load (70 of 1RM) resistance training (RT) have similar effects on femoral neck and lumbar spine bone mineral density (BMD) in middle-aged and older people.

Original title:
High and Low-Load Resistance Training Produce Similar Effects on Bone Mineral Density of Middle-Aged and Older People: A Systematic Review With Meta-Analysis of Randomized Clinical Trials by Souza D, Barbalho M, […], Gentil P.

Link:
https://www.sciencedirect.com/science/article/abs/pii/S0531556520303211?via%3Dihub

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

Objectives:
Nitric oxide related ergogenic aids such as arginine (Arg) have shown to impact positively on sport performance through several physiological and metabolic mechanisms. However, research results have shown to be controversial. Therefore, this review article has been conducted.

Do both acute and chronic arginine supplementation increase aerobic (≤VO2max) and anaerobic (>VO2max) performance?

Study design:
This review article included 15 RCTs with 386 males and 8 females.

Arginine supplementation was ingested by participants in both acute and chronic protocols.
Acute arginine protocol was 0.15 g/kg (≈10-11 g) ingested between 60-90 minutes before physical exercises.

Chronic arginine protocol was 1.5-2 g/day during 4-7 weeks or 10-12 g/day during 8 weeks.

Random effects model and pooled standardized mean differences (SMD) were used according to Hedges’ g.

Egger’s analyses did not find publication bias in anaerobic performance [z = 0.786, p = 0.432]. However, funnel plot showed publication bias in aerobic performance data [z = 2.873, p 0.05].

Results and conclusions:
The investigators found both acute and chronic arginine supplementation significantly improved anaerobic performance [SMD = 0.24, 95% CI = 0.05 to 0.43, p = 0.01, I2 = 0%, p = 0.85].

The investigators found both acute and chronic arginine supplementation significantly improved aerobic performance [SMD = 0.84, 95% CI = 0.12 to 1.56, p = 0.02, I2 = 89%, p 0.001].

The investigators concluded both acute and chronic arginine supplementation improve (anaerobic/aerobic) performance.

Original title:
Effects of Arginine Supplementation on Athletic Performance Based on Energy Metabolism: A Systematic Review and Meta-Analysis by Viribay A, Burgos J, […], Mielgo-Ayuso J.

Link:
https://www.mdpi.com/2072-6643/12/5/1300/htm

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

Objectives:
Does protein supplementation yield beneficial effects on body composition and muscle function (strength and synthesis) in healthy adults, with an emphasis on the timing of protein intake?

Study design:
This review article included 65 RCTs with 2,907 participants (1,514 men and 1,380 women, 13 unknown sex). 26, 8 and 24 studies were used for meta-analysis on lean body mass, handgrip strength and leg press strength, respectively.

Results and conclusions:
The investigators found protein supplementation was effective in improving lean body mass (LBM) in adults [MD = 0.62 kg, 95% CI = 0.36 to 0.88] and older adults [MD = 0.46 kg, 95% CI = 0.23 to 0.70].
Sensitivity analyses removing studies without exercise training had no impact on the outcome.

The investigators found no association between protein supplementation and handgrip strength [older adults: MD = 0.26 kg, 95% CI = -0.51 to 1.04] and leg press strength [adults: MD = 5.80 kg, 95% CI = -0.33 to 11.93 and older adults: MD = 1.97 kg, 95% CI = -2.78 to 6.72].
Sensitivity analyses removing studies without exercise training had no impact on the outcome.

The investigators found data regarding muscle synthesis were scarce and inconclusive.

The investigators found subgroup analyses showed no beneficial effect of a specific timing of protein intake on lean body mass, handgrip strength and leg press strength.

The investigators concluded there is a positive impact of protein supplementation on lean body mass of healthy adults and older adults, independently of intake timing.

Original title:
The Role of Protein Intake and its Timing on Body Composition and Muscle Function in Healthy Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials by Wirth J, Hillesheim E and Brennan L.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/32232404

Additional information of El Mondo:
Find more information/studies on protein and sport nutrition right here.

The more lean body mass a person has, the higher their resting metabolic rate. Resting metabolic rate is the total number of calories burned when your body is completely at rest. Resting metabolic rate supports breathing, circulating blood, organ functions and basic neurological functions.

Objectives:
Which types of exercise training (whole body vibration training, aerobic training, strength training and combined training) increase lumbar spine and femoral neck bone mineral density (BMD) in older postmenopausal women (PMW)?

Study design:
This review article included 16 RCTs with 1,624 subjects.

Results and conclusions:
The investigators found no significant change in lumbar spine bone mineral density following exercise training [MD = 0.01 g/cm², 95% CI = -0.01 to 0.02].

The investigators found no significant change in femoral neck bone mineral density following exercise training [MD = 0.00 g/cm², 95% CI = -0.01 to 0.01].

The investigators found, however, subgroup analysis by type of exercise training revealed that lumbar spine bone mineral density [MD = 0.01, 95% CI = 0.00 to 0.02] raised significantly when whole-body vibration (WBV) was employed as intervention compared with RCTs that utilized aerobic [MD = -0.01, 95% CI = -0.02 to -0.01], resistance [MD = 0.01, 95% CI = -0.04 to 0.06] or combined training [MD = 0.03, 95% CI = -0.01 to 0.08].

The investigators found, on the other hand, lumbar spine bone mineral density [MD = - 0.01, 95% CI = -0.02 to -0.01] reduced significantly when aerobic exercise training was used as intervention compared with RCTs that utilized resistance training, combined training or whole-body vibration. 

The investigators concluded whole-body vibration is an effective method to improve lumbar spine bone mineral density in older postmenopausal women.

Original title:
The Impact of Different Modes of Exercise Training on Bone Mineral Density in Older Postmenopausal Women: A Systematic Review and Meta-analysis Research by Mohammad Rahimi GR, Smart NA, […], Mohammad Rahimi N.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/32055889

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

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.