Protein Ingestion before Sleep Increases Overnight Muscle Protein Synthesis Rates in Healthy Older Men: A Randomized Controlled Trial

Presleep Protein Supplementation Does Not Improve Recovery During Consecutive Days of Intense Endurance Training: A Randomized Controlled Trial

Recent studies demonstrate that protein ingestion immediately before sleep improves muscle recovery during the night following resistance exercise. Whether this feeding strategy benefits recovery from endurance training has yet to be established. The aim of this study was to investigate the effects of whey protein isolate ingested every night before sleep on subsequent performance and circulatory markers of muscular recovery during a week of intensified endurance training mimicking a training camp. In a parallel design, 32 trained runners underwent a 1-week intervention with a rigorously controlled diet (carbohydrate = 7.2 g·kg^-1·day^-1, protein = 1.8 g·kg^-1·day^-1, and fat = 1.0 g·kg^-1·day^-1) and exercise program (11 sessions) while receiving either a protein (0.5 g·kg^-1·day^-1) or carbohydrate (0.5 g·kg^-1·day^-1) beverage every night before sleep. Blood samples were obtained on the morning of Days 1, 4, 7, and 8 and analyzed for markers of muscle damage (creatine kinase, lactate dehydrogenase, and myoglobin). The postintervention 5-km time-trial performance was significantly impaired in both groups (11 ± 24 s, p < .01). Plasma creatine kinase (227% ± 221%, p < .01), lactate dehydrogenase (18% ± 22%, p < .01), and myoglobin (72% ± 62%, p < .01) increased gradually throughout the week with no difference between the groups (p > .05). In conclusion, the presleep protein ingestion did not reduce the decline in performance or ameliorate the rise of circulatory markers of muscle damage during a week of intensified training when compared with the isocaloric carbohydrate ingestion.

Nutrition Recommendations for Bodybuilders in the Off-Season: A Narrative Review

Many nutrition practices often used by bodybuilders lack scientific support and can be detrimental to health. Recommendations during the dieting phase are provided in the scientific literature, but little attention has been devoted to bodybuilders during the off-season phase. During the off-season phase, the goal is to increase muscle mass without adding unnecessary body fat. This review evaluated the scientific literature and provides nutrition and dietary supplement recommendations for natural bodybuilders during the off-season phase. A hyper-energetic diet (~10–20%) should be consumed with a target weight gain of ~0.25–0.5% of bodyweight/week for novice/intermediate bodybuilders. Advanced bodybuilders should be more conservative with the caloric surplus and weekly weight gain. Sufficient protein (1.6–2.2 g/kg/day) should be consumed with optimal amounts 0.40–0.55 g/kg per meal and distributed evenly throughout the day (3–6 meals) including within 1–2 hours pre- and post-training. Fat should be consumed in moderate amounts (0.5–1.5 g/kg/day). Remaining calories should come from carbohydrates with focus on consuming sufficient amounts (≥3–5 g/kg/day) to support energy demands from resistance exercise. Creatine monohydrate (3–5 g/day), caffeine (5–6 mg/kg), beta-alanine (3–5 g/day) and citrulline malate (8 g/day) might yield ergogenic effects that can be beneficial for bodybuilders.

Dietary Protein Quantity, Quality, and Exercise Are Key to Healthy Living: A Muscle-Centric Perspective Across the Lifespan

A healthy eating pattern, regardless of age, should consist of ingesting high quality protein preferably in adequate amounts across all meals throughout the day. Of particular relevance to overall health is the growth, development, and maintenance of skeletal muscle tissue. Skeletal muscle not only contributes to physical strength and performance, but also contributes to efficient macronutrient utilization and storage. Achieving an optimal amount of muscle mass begins early in life with transitions to "steady-state" maintenance as an adult, and then safeguarding against ultimate decline of muscle mass with age, all of which are influenced by physical activity and dietary (e.g., protein) factors. Current protein recommendations, as defined by recommended dietary allowances (RDA) for the US population or the population reference intakes (PRI) in Europe, are set to cover basic needs; however, it is thought that a higher protein intake might be necessary for optimizing muscle mass, especially for adults and individuals with an active lifestyle. It is necessary to balance the accurate assessment of protein quality (e.g., digestible indispensable amino acid score; DIAAS) with methods that provide a physiological correlate (e.g., established measures of protein synthesis, substrate oxidation, lean mass retention, or accrual, etc.) in order to accurately define protein requirements for these physiological outcomes. Moreover, current recommendations need to shift from single nutrient guidelines to whole food based guidelines in order to practically acknowledge food matrix interactions and other required nutrients for potentially optimizing the health effects of food. The aim of this paper is to discuss protein quality and amount that should be consumed with consideration to the presence of non-protein constituents within a food matrix and potential interactions with physical activity to maximize muscle mass throughout life.

The Impact of Pre-sleep Protein Ingestion on the Skeletal Muscle Adaptive Response to Exercise in Humans: An Update

This review provides an update on recent research assessing the effect of pre-sleep protein ingestion on muscle protein synthesis rates during overnight sleep and the skeletal muscle adaptive response to exercise training. Protein ingested prior to sleep is effectively digested and absorbed during overnight sleep, thereby increasing overnight muscle protein synthesis rates. Protein consumption prior to sleep does not appear to reduce appetite during breakfast the following day and does not change resting energy expenditure. When applied over a prolonged period of resistance-type exercise training, pre-sleep protein supplementation has a beneficial effect on the increase in muscle mass and strength. Protein ingestion before sleep is hypothesized to represent an effective nutritional strategy to preserve muscle mass in the elderly, especially when combined with physical activity or muscle contraction by means of neuromuscular electrical stimulation. In conclusion, protein ingestion prior to sleep is an effective interventional strategy to increase muscle protein synthesis rates during overnight sleep and can be applied to support the skeletal muscle adaptive response to resistance-type exercise training.

Presleep Casein Protein Ingestion: Acceleration of Functional Recovery in Professional Soccer Players

PURPOSE

To examine whether consuming casein protein (CP) before sleep would enhance recovery after a nighttime soccer match in professional players.

METHODS

In a randomized, crossover design, 10 professional soccer players from the reserve squad of a team in the highest tier of English soccer consumed 40 g of CP or 40 g of carbohydrates (CON) 30 min presleep after a soccer match (kick off: 7 PM). To assess recovery, countermovement-jump height, reactive strength index, muscle soreness, and the adapted Brief Assessment of Mood (BAM+) Questionnaire were measured before and 12, 36, and 60 h after each match. Dietary intake across the testing period was also recorded.

RESULTS

There were unclear differences in external load in the matches and dietary intake between CON and CP. Casein protein had a most likely and likely beneficial effect on countermovement-jump recovery at 12 and 36 h postmatch (CP -1.6; ±1.2% vs CON -6.6; ±1.7%; -4.1; ±2.3% vs -0.4; ±1.1%, respectively). Reactive strength index recovery was most likely enhanced with CP at 12 and 36 h postmatch, and muscle soreness, as measured with a visual analog scale (in millimeters), was most likely greater in CON versus CP at 12 h postmatch (72; ±17 vs 42; ±20 mm). BAM+ was possibly lower in CON at 36 h postmatch but unaffected at other time points.

CONCLUSIONS

Presleep CP accelerates functional recovery in professional soccer players and, therefore, provides a practical means of attenuating performance deficits in the days after a match.

Dose, timing, and source of protein intake of young people with spastic cerebral palsy

Purpose: Since the dose, timing and source of dietary protein intake are important for muscle growth and development, the aim of this study was to examine the dose, timing and source of protein intake of young people with cerebral palsy.Materials and methods: Dietary intake was assessed in 19 children with spastic cerebral palsy (Gross Motor Function Classification System levels I-V; Eating and Drinking Classification System levels I-V; 10 males, 9 females; mean [SD] age 11 years 2 months [3 years 3 months]) using a 3-day food diary. The data were analyzed for three age categories (4-8, 9-13, and 14-17 years).Results: Average 3-day protein intake (62.1 g [27.9 g]) was within the recommended boundaries with a minimum of 1.0 g/kg body weight/day and a maximum of 4.1 g/kg body weight/day. However, dinner was the only mealtime that provided at least 25 g of protein, which is needed for optimal muscle maintenance. The main food groups that contributed to protein intake were 'milk and milk products', 'meat, meat products and poultry', and 'bread'.Conclusions: These observations suggest timing of protein intake can be improved with higher intakes during breakfast and lunch to better support skeletal muscle growth and development.IMPLICATIONS FOR REHABILITATIONRecent studies have shown that smaller muscles and early atrophy are already present at young age in individuals with cerebral palsy.Besides physical training, adequate protein intake (with optimal dose, timing and source of protein) may be a key factor in the prevention and treatment of loss of muscle mass in children with cerebral palsy.In a relatively small sample this study shows that overall protein intake (dose) was in line with recommendations and also that the source of the protein seemed sufficient to contain all essential amino acids.Improvement of the timing of protein intake throughout the day, with higher intakes during breakfast and lunch, seems important to better support skeletal muscle growth and development.

Rehabilitation Nutrition for Iatrogenic Sarcopenia and Sarcopenic Dysphagia

Sarcopenia is a very important issue in rehabilitation medicine and nutritional care. The prevalence of sarcopenia in older people is approximately 50% in the rehabilitation setting, and also approximately 15% of inpatients without sarcopenia upon admission developed sarcopenia during hospitalization. There is a concern that secondary sarcopenia may occur iatrogenically during hospitalization. Iatrogenic sarcopenia is defined as sarcopenia caused by the activities of medical staff including doctors, nurses, or other health care professionals in healthcare facilities. Iatrogenic sarcopenia is categorized into activity-related, nutrition-related and disease-related-iatrogenic sarcopenia. Especially in acute phase hospitals, concentrating on the treatment of diseases with less attention to nutrition and activity is more likely to cause iatrogenic sarcopenia. Sarcopenic dysphagia is also an important aspect in rehabilitation medicine and nutritional care. Sarcopenic dysphagia is characterized by swallowing difficulty because of a loss of mass and function in whole-body skeletal and swallowing muscles. Sarcopenic dysphagia can be diagnosed using a 5-step algorithm for the condition. Iatrogenic sarcopenia and sarcopenic dysphagia are affected by nutrition, activity and diseases in a complex manner. Therefore, treatment of iatrogenic sarcopenia and sarcopenic dysphagia requires comprehensive interventions through nutrition management and rehabilitation. Rehabilitation nutrition is effective for preventing and treating iatrogenic sarcopenia and sarcopenic dysphagia. Rehabilitation nutrition can be practiced more effectively and comprehensively by using the rehabilitation nutrition care process, which is a systematic problem-solving method. Further research is required to verify the efficacy of rehabilitation nutrition for preventing or improving iatrogenic sarcopenia and/or sarcopenic dysphagia.

Protein Intake Falls below 0.6 g•kg-1•d-1 in Healthy, Older Patients Admitted for Elective Hip or Knee Arthroplasty

OBJECTIVE

Hospitalization is generally accompanied by changes in food intake. Patients typically receive hospital meals upon personal preference within the framework of the food administration services of the hospital. In the present study, we assessed food provision and actual food and snack consumption in older patients admitted for elective hip or knee arthroplasty.

DESIGN

A prospective observational study.

SETTING

Orthopedic nursing ward of the Maastricht University Medical Centre+.

PARTICIPANTS

In the present study, n=101 patients (age: 67±10 y; hospital stay: 6.1±1.8 d) were monitored during hospitalization following elective hip or knee arthroplasty.

MEASUREMENTS

Energy and protein provided by self-selected hospital meals and snacks, and actual energy and protein (amount, distribution, and source) consumed by patients was weighed and recorded throughout 1-6 days.

RESULTS

Self-selected meals provided 6.5±1.5 MJ•d-1, with 16, 48, and 34 En% provided as protein, carbohydrate, and fat, respectively. Self-selected hospital meals provided 0.75±0.16 and 0.79±0.21 g•kg-1•d-1 protein in males and females, respectively. Actual protein consumption averaged merely 0.59±0.18 and 0.50±0.21 g•kg-1•d-1, respectively. Protein consumption at breakfast, lunch, and dinner averaged 16±8, 18±9, and 20±6 g per meal, respectively.

CONCLUSIONS

Though self-selected hospital meals provide patients with ~0.8 g•kg-1•d-1 protein during short-term hospitalization, actual protein consumption falls well below 0.6 g•kg-1•d-1 with a large proportion (~32%) of the provided food being discarded. Alternative strategies are required to ensure maintenance of habitual protein intake in older patients admitted for elective orthopedic surgery.

Pre-Bed Casein Protein Supplementation Does Not Enhance Acute Functional Recovery in Physically Active Males and Females When Exercise is Performed in the Morning

This study examined whether consuming casein protein (CP) pre-sleep could accelerate acute recovery following muscle-damaging exercise. Thirty-nine active males and females performed 100 drop jumps in the morning, consumed their habitual diet during the day, and then within 30 min pre-bed consumed either ~40 g of CP (n = 19) or ~40 g of a carbohydrate-only control (CON) (n = 20). Maximal isometric voluntary contractions (MIVC), countermovement jumps (CMJ), pressure-pain threshold (PPT), subjective muscle soreness and the brief assessment of mood adapted (BAM+) were measured pre, 24 and 48 h following the drop jumps. MIVC decreased in CP and CON post-exercise, peaking at 24 h post (CP: -8.5 ± 3.5 vs. CON: -13.0 ± 2.9%, respectively); however, no between-group differences were observed (p = 0.486; η_p² =0.02). There were also no group differences in the recovery of CMJ height, PPT and BAM+ (p > 0.05). Subjective muscle soreness increased post-exercise, but no group differences were present at 24 h (CP: 92 ± 31 mm vs. CON: 90 ± 46 mm) or 48 h (CP: 90 ± 44 mm vs. CON: 80 ± 58 mm) (p > 0.05). These data suggest that pre-bed supplementation with ~40 g of CP is no more beneficial than CON for accelerating the recovery following muscle-damaging exercise.

Protein Supplementation after Exercise and before Sleep Does Not Further Augment Muscle Mass and Strength Gains during Resistance Exercise Training in Active Older Men

Background

The proposed benefits of protein supplementation on the skeletal muscle adaptive response to resistance exercise training in older adults remain unclear.

Objective

The present study assessed whether protein supplementation after exercise and before sleep augments muscle mass and strength gains during resistance exercise training in older individuals.

Methods

Forty-one older men [mean ± SEM age: 70 ± 1 y; body mass index (kg/m2): 25.3 ± 0.4] completed 12 wk of whole-body resistance exercise training (3 sessions/wk) and were randomly assigned to ingest either protein (21 g protein, 3 g total leucine, 9 g carbohydrate, 3 g fat; n = 21) or an energy-matched placebo (0 g protein, 25 g carbohydrate, 6 g fat; n = 20) after exercise and each night before sleep. Maximal strength was assessed by 1-repetition-maximum (1RM) strength testing, and muscle hypertrophy was assessed at the whole-body (dual-energy X-ray absorptiometry), upper leg (computed tomography scan), and muscle fiber (biopsy) levels. Muscle protein synthesis rates were assessed during week 12 of training with the use of deuterated water (2H2O) administration.

Results

Leg-extension 1RM increased in both groups (placebo: 88 ± 3 to 104 ± 4 kg; protein: 85 ± 3 to 102 ± 4 kg; P < 0.001), with no differences between groups. Quadriceps cross-sectional area (placebo: 67.8 ± 1.7 to 73.5 ± 2.0 cm2; protein: 68.4 ± 1.4 to 72.3 ± 1.4 cm2; P < 0.001) increased in both groups, with no differences between groups. Muscle fiber hypertrophy occurred in type II muscle fibers (placebo: 5486 ± 418 to 6492 ± 429 µm2; protein: 5367 ± 301 to 6259 ± 391 µm2; P < 0.001), with no differences between groups. Muscle protein synthesis rates were 1.62% ± 0.06% and 1.57% ± 0.05%/d in the placebo and protein groups, respectively, with no differences between groups.

Conclusion

Protein supplementation after exercise and before sleep does not further augment skeletal muscle mass or strength gains during resistance exercise training in active older men. This study was registered at the Netherlands Trial Registry (www.trialregister.nl) as NTR5082.

Protein for Life: Review of Optimal Protein Intake, Sustainable Dietary Sources and the Effect on Appetite in Ageing Adults

With an ageing population, dietary approaches to promote health and independence later in life are needed. In part, this can be achieved by maintaining muscle mass and strength as people age. New evidence suggests that current dietary recommendations for protein intake may be insufficient to achieve this goal and that individuals might benefit by increasing their intake and frequency of consumption of high-quality protein. However, the environmental effects of increasing animal-protein production are a concern, and alternative, more sustainable protein sources should be considered. Protein is known to be more satiating than other macronutrients, and it is unclear whether diets high in plant proteins affect the appetite of older adults as they should be recommended for individuals at risk of malnutrition. The review considers the protein needs of an ageing population (>40 years old), sustainable protein sources, appetite-related implications of diets high in plant proteins, and related areas for future research.

Impact of Dietary Fiber Consumption on Insulin Resistance and the Prevention of Type 2 Diabetes

Large prospective cohort studies consistently show associations of a high dietary fiber intake (>25 g/d in women and >38 g/d in men) with a 20-30% reduced risk of developing type 2 diabetes (T2D), after correction for confounders. It is less well recognized that these effects appear to be mainly driven by high intakes of whole grains and insoluble cereal fibers, which typically are nonviscous and do not relevantly influence postprandial glucose responses [i.e., glycemic index (GI)] or are strongly fermented by the gut microbiota in the colon. In contrast, a dietary focus on soluble, viscous, gel-forming, more readily fermentable fiber intakes derived from fruit and certain vegetables yields mixed results and generally does not appear to reduce T2D risk. Although disentangling types of fiber-rich foods and separating these from possible effects related to the GI is an obvious challenge, the common conclusion that key metabolic effects of high-fiber intake are explained by mechanisms that should mainly apply to the soluble, viscous type can be challenged. More recently, studies in humans and animal models focused on gaining mechanistic insights into why especially high-cereal-fiber (HCF) diets appear to improve insulin resistance (IR) and diabetes risk. Although effects of HCF diets on weight loss are only moderate and comparable to other types of dietary fibers, possible novel mechanisms have emerged, which include the prevention of the absorption of dietary protein and modulation of the amino acid metabolic signature. Here we provide an update of our previous review from 2008, with a focus on mechanistic insights of how HCF diets may improve IR and the risk of developing T2D.