Sports Dietitians Australia Position Statement: Nutrition for Exercise in Hot Environments.

It is the position of Sports Dietitians Australia (SDA) that exercise in hot and/or humid environments, or with significant clothing and/or equipment that prevents body heat loss (i.e., exertional heat stress), provides significant challenges to an athlete's nutritional status, health, and performance. Exertional heat stress, especially when prolonged, can perturb thermoregulatory, cardiovascular, and gastrointestinal systems. Heat acclimation or acclimatization provides beneficial adaptations and should be undertaken where possible. Athletes should aim to begin exercise euhydrated. Furthermore, preexercise hyperhydration may be desirable in some scenarios and can be achieved through acute sodium or glycerol loading protocols. The assessment of fluid balance during exercise, together with gastrointestinal tolerance to fluid intake, and the appropriateness of thirst responses provide valuable information to inform fluid replacement strategies that should be integrated with event fuel requirements. Such strategies should also consider fluid availability and opportunities to drink, to prevent significant under- or overconsumption during exercise. Postexercise beverage choices can be influenced by the required timeframe for return to euhydration and co-ingestion of meals and snacks. Ingested beverage temperature can influence core temperature, with cold/icy beverages of potential use before and during exertional heat stress, while use of menthol can alter thermal sensation. Practical challenges in supporting athletes in teams and traveling for competition require careful planning. Finally, specific athletic population groups have unique nutritional needs in the context of exertional heat stress (i.e., youth, endurance/ultra-endurance athletes, and para-sport athletes), and specific adjustments to nutrition strategies should be made for these population groups.

Correction: Development and validation of a novel risk score for the detection of insignificant prostate cancer in unscreened patient cohorts.

Since the publication of this paper, the authors noticed that Amar Ahmad was not credited as contributing equally to the paper. He should be considered as a joint first author with Lorenzo Dutto. In addition, the author Ashwin Sridhar was incorrectly listed as Ashwin Shridhar, and the author Gregory L. Shaw was incorrectly listed as Gregory Shaw. The correct names are listed above.

Rehabilitation and nutrition protocols for optimising return to play from traditional ACL reconstruction in elite rugby union players: A case study.

Current nutrition and exercise focus during rehabilitation periods has been on reducing muscle atrophy associated with immobilisation. This case report outlines a best practice anterior cruciate ligament (ACL) rehabilitation programme undertaken by two professional rugby athletes, with the addition of an evidence-based supplementation (gelatine and vitamin C) and exercise protocol focused on collagenous tissue. Both players ruptured their left ACL and were repaired with a traditional hamstring graft. Players undertook a structured rehabilitation programme for 34 weeks before being clinically assessed ready to play. Players saw minimal changes in body composition in the early rehabilitation period (P1 - 0.8 kg; P2 - 0.4 kg). Leg lean mass reduced in both legs of Player 1 (Injured - 0.8 kg, Non-injured - 0.6 kg) at 17 weeks, with Player 2 only experiencing a loss of 0.3 kg of lean tissue in the injured leg. Both players returned to baseline body compositions after 24 weeks. Leg strength returned to a maximum at 24 and 15 weeks, respectively, with knee function returning to baseline by 30 weeks. This case report provides evidence that nutrition and rehabilitation programmes targeted at minimising the effects of disuse in both muscle and connective tissue may assist return to play after ACL injury.

Bone Broth Unlikely to Provide Reliable Concentrations of Collagen Precursors Compared With Supplemental Sources of Collagen Used in Collagen Research.

Intake of dietary sources of collagen may support the synthesis of collagen in varying tissues, with the availability of key amino acids being a likely contributor to its effectiveness. This study analyzed commonly consumed preparations of bone broth (BB) to assess the amount and consistency of its amino acid content. Commercial and laboratory-prepared samples, made with standardized and variable (nonstandardized) protocols, were analyzed for key amino acids (glycine, lysine, proline, leucine, hydroxyproline, and hydroxylysine). The main finding of this study was that amino acid concentrations in BB made to a standardized recipe were significantly lower for hydroxyproline, glycine, and proline (p = .003) and hydroxylysine, leucine, and lysine (p = .004) than those provided by a potentially therapeutic dose (20 g) of reference collagen supplements (p > .05). There was a large variability in the amino acid content of BB made to nonstandardized recipes, with the highest levels of all amino acids found within the café-prepared varieties. For standardized preparations, commercial BBs were lower in all amino acids than the self-prepared varieties. There were no differences (p > .05) in the amino acid content of different batches of BB when prepared according to a standardized recipe. If the intake of collagen precursors is proven to support the synthesis of new collagen in vivo, it is unlikely that BB can provide a consistently reliable source of key amino acids. Research on the provision of key amino acids from dietary sources should continue to focus on the standard sources currently being researched.

Urinary Hydroxyproline Is Only Suitable As a Biomarker for Acute Intake, Up to 6 hr Postingestion of Collagen Proteins in "Free-Living," Healthy, Active Males.

The urinary excretion of hydroxyproline (Hyp), abundant in collagen protein, may serve as a biomarker of habitual collagen intake, assisting with investigations of current interest in the role of dietary collagen intake in supporting the synthesis of collagenous body tissues. This study investigated the time course of urinary Hyp excretion in "free-living," healthy, active males following the ingestion of a standardized bolus (20 g) of collagenous (gelatin and a hydrolyzed collagen powder) and dairy (calcium caseinate and hydrolyzed casein) proteins. The excretion of Hyp was assessed over a 24-hr period, separated into three collection periods: 0-6, 6-12, and 12-24 hr. Hyp was elevated for 0-6 hr after the consumption of collagen-containing supplements (gelatin 31.3 ± 8.8 mmol/mol and hydrolyzed collagen 33.7 ± 22.0 mmol/mol vs. baseline: gelatin 2.4 ± 1.7 mmol/mol and hydrolyzed collagen 2.8 ± 1.5 mmol/mol; p < .05), but not for the dairy protein supplements (calcium caseinate 3.4 ± 1.7 mmol/mol and hydrolyzed casein 4.0 ± 3.7 mmol/mol; p > .05). Therefore, urinary Hyp reflects an acute intake of collagenous protein, but is not suitable as a biomarker for quantifying habitual collagen intake, provided through regular dietary practices in "free-living," healthy, active males.

Development and validation of a novel risk score for the detection of insignificant prostate cancer in unscreened patient cohorts.

BACKGROUND: Active surveillance is recommended for insignificant prostate cancer (PCa). Tools exist to identify suitable candidates using clinical variables. We aimed to develop and validate a novel risk score (NRS) predicting which patients are harbouring insignificant PCa. METHODS: We used prospectively collected data from 8040 consecutive unscreened patients who underwent radical prostatectomy between 2006 and 2016. Of these, data from 2799 patients with Gleason 3 + 3 on biopsy were used to develop a multivariate model predicting the presence of insignificant PC at radical prostatectomy (ERSPC updated definition3: Gleason 3 + 3 only, index tumour volume < 1.3 cm3 and total tumour volume < 2.5 cm3). This was used to develop a novel risk score (NRS) which was validated in an equivalent independent cohort (n = 441). We compared the accuracy of existing predictive tools and the NRS in these cohorts. RESULTS: The NRS (incorporating PSA, prostate volume, age, clinical T Stage, percent and number of positive biopsy cores) outperformed pre-existing predictive tools in derivation and validation cohorts (AUC 0.755 and 0.76, respectively). Selection bias due to analysis of a surgical cohort is acknowledged. CONCLUSIONS: The advantage of the NRS is that it can be tailored to patient characteristics and may prove to be valuable tool in clinical decision-making.

Supplement Use of Elite Australian Swimmers.

This study examined the influence the Australian Institute of Sport (AIS) Sport Supplement Program had on supplement practices of elite Australian swimmers, comparing those guided by the Program with others in the same national team. Thirty-nine elite swimmers (13 AIS, 26 Other; 20 female, 19 male; age 21.8 ± 3.3 y) completed a questionnaire investigating supplement use. Ninety-seven percent of swimmers reported taking supplements or sports foods over the preceding 12 months. AIS swimmers reported using more total brands (p = .02) and supplements considered Ergogenic (p = .001) than Other swimmers who used more supplements considered to be lacking scientific support (p = .028). Swimmers rated the risk of a negative outcome from the use of supplements available in Australia (Mdn = 3.0) as less than the risk of supplements from international sources (Mdn = 4.0; p < .001). AIS swimmers were more likely to report dietitians (p < .001) and sports physicians (p = .017) as advisors of their supplement use. Other swimmers more frequently reported fellow athletes as a source of supplement advice (p = .03). AIS swimmers sourced a greater percentage of their supplements from an organized program (94 ± 16%) compared with Other (40 ± 32%; p < .001) who sourced a greater percentage (30 ± 30%) of their dietary supplements from supermarkets. These findings suggest that swimmers influenced by this sport supplement program more frequently use supplements that are recommended by allied health trained individuals, classified as evidence based and provided by the program.

Changes in the Supplementation Practices of Elite Australian Swimmers Over 11 Years.

Thirty nine elite Australian swimmers (13 AIS, 26 OTHER) completed a standardized questionnaire regarding their supplement use during a pre competition camp. The data were compared with a similar study conducted 11 years earlier (11 AIS, 23 OTHER) and framed around the classification system of the Sport Supplement Program of the Australian Institute of Sport. The prevalence of supplement use remained constant over time (2009: 97%, 1998: 100%). However, the current swimmers used a greater number of dietary supplements (9.2 ± 3.7 and 5.9 ± 2.9; p = .001), accounted for by an increase in the reported use of supplements with a greater evidence base (Sports Foods, Ergogenics, and Group B supplements). In contrast, fewer supplements considered less reputable (Group C and D) were reported by the 2009 cohort (0.7 ± 1.0 and 1.6 ± 1.3; p = .003). AIS swimmers reported a greater use of Ergogenics (4.3 ± 1.8 and 3.1 ± 1.7; p = .002), and less use of Group C and D supplements overall (0.8 ± 1.2 and 1.3 ± 1.2; p = .012), which was explained primarily by a smaller number of these supplements reported by the 2009 group (1998 AIS: 1.5 ± 1.4, 2009 AIS: 0.2 ± 0.6; p = .004). Although the prevalence of supplement use has not changed over time, there has been a significant increase in the number and type of products they are using. The potential that these changes can be attributed to a Sports Supplement Program merit investigation.

Nutrition considerations for open-water swimming.

Open-water swimming (OWS) is a rapidly developing discipline. Events of 5-25 km are featured at FINA World Championships, and the international circuit includes races of 5-88 km. The Olympic OWS event, introduced in 2008, is contested over 10 km. Differing venues present changing environmental conditions, including water and ambient temperatures, humidity, solar radiation, and unpredictable tides. Furthermore, the duration of most OWS events (1-6 hr) creates unique physiological challenges to thermoregulation, hydration status, and muscle fuel stores. Current nutrition recommendations for open-water training and competition are either an extension of recommendations from pool swimming or are extrapolated from other athletic populations with similar physiological requirements. Competition nutrition should focus on optimizing prerace hydration and glycogen stores. Although swimmers should rely on self-supplied fuel and fluid sources for shorter events, for races of 10 km or greater, fluid and fuel replacement can occur from feeding pontoons when tactically appropriate. Over the longer races, feeding pontoons should be used to achieve desirable targets of up to 90 g/ hr of carbohydrates from multitransportable sources. Exposure to variable water and ambient temperatures will play a significant role in determining race nutrition strategies. For example, in extreme environments, thermoregulation may be assisted by manipulating the temperature of the ingested fluids. Swimmers are encouraged to work with nutrition experts to develop effective and efficient strategies that enhance performance through appropriate in-competition nutrition.

Nutrition for swimming.

Swimming is a sport that requires considerable training commitment to reach individual performance goals. Nutrition requirements are specific to the macrocycle, microcycle, and individual session. Swimmers should ensure suitable energy availability to support training while maintaining long term health. Carbohydrate intake, both over the day and in relation to a workout, should be manipulated (3-10 g/kg of body mass/day) according to the fuel demands of training and the varying importance of undertaking these sessions with high carbohydrate availability. Swimmers should aim to consume 0.3 g of high-biological-value protein per kilogram of body mass immediately after key sessions and at regular intervals throughout the day to promote tissue adaptation. A mixed diet consisting of a variety of nutrient-dense food choices should be sufficient to meet the micronutrient requirements of most swimmers. Specific dietary supplements may prove beneficial to swimmers in unique situations, but should be tried only with the support of trained professionals. All swimmers, particularly adolescent and youth swimmers, are encouraged to focus on a well-planned diet to maximize training performance, which ensures sufficient energy availability especially during periods of growth and development. Swimmers are encouraged to avoid rapid weight fluctuations; rather, optimal body composition should be achieved over longer periods by modest dietary modifications that improve their food choices. During periods of reduced energy expenditure (taper, injury, off season) swimmers are encouraged to match energy intake to requirement. Swimmers undertaking demanding competition programs should ensure suitable recovery practices are used to maintain adequate glycogen stores over the entirety of the competition period.

Selective catalytic oxidation using supported gold-platinum and palladium-platinum nanoalloys prepared by sol-immobilisation.

Supported nano-alloys have been prepared using the sol-immobilisation method for two bimetallic combinations, namely gold-platinum and palladium-platinum, using activated carbon and titania as supports. Some of the materials were prepared using a method where both metals are simultaneously reduced, thereby leading to homogeneous alloys being formed. In addition, sequential reduction of the metal combinations has also been investigated to facilitate the formation of core-shell structures. The materials have been characterized using X-ray photoelectron spectroscopy and aberration-corrected scanning transmission electron microscopy. The supported nanoparticles have been tested for a two selective oxidation reactions, namely the oxidation of toluene and benzyl alcohol using tertiary butyl hydroperoxide at 80 °C, in order to elucidate any potential structure-activity relationships.

Complications After Radical Cystectomy: A Systematic Review and Meta-analysis of Randomized Controlled Trials with a Meta-regression Analysis.

CONTEXT: Radical cystectomy is considered a procedure of high complexity with a relative high complication rate. OBJECTIVE: To systematically summarize the literature regarding the complications of radical cystectomy and the factors that contribute to them. EVIDENCE ACQUISITION: We searched MEDLINE/PubMed, ClinicalTrials.gov, and Cochrane Library, according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines for randomized controlled trials (RCTs) on complications related to radical cystectomy. EVIDENCE SYNTHESIS: A total of 3766 studies were screened, and 44 studies were included in this systematic review and meta-analysis. Complications following radical cystectomy are quite common. The most common complications were gastrointestinal complications (20%), infectious complications (17%), and ileus (14%). The majority of complications occurring were Clavien I-II (45%). Specific measurable patient factors are related to certain complications and can be used to stratify risk and assist in preoperative counseling, while proper design of high-quality RCTs may better reflect real-life complication rates. CONCLUSIONS: In our study, RCTs with a low risk of bias had higher complication rates than studies with a high risk of bias, underlining the need for further improvement on complication reporting in order to refine surgical outcomes. PATIENT SUMMARY: Radical cystectomy is usually followed by high complication rates, which affect patients and are, in turn, strongly associated with patients' preoperative health status.

Feasibility of aspirin and/or vitamin D3 for men with prostate cancer on active surveillance with Prolaris® testing.

Objectives: To test the feasibility of a randomised controlled trial (RCT) of aspirin and/or vitamin D3 in active surveillance (AS) low/favourable intermediate risk prostate cancer (PCa) patients with Prolaris® testing. Patients and Methods: Newly-diagnosed low/favourable intermediate risk PCa patients (PSA ≤ 15 ng/ml, International Society of Urological Pathology (ISUP) Grade Group ≤2, maximum biopsy core length <10 mm, clinical stage ≤cT2c) were recruited into a multi-centre randomised, double-blind, placebo-controlled study (ISRCTN91422391, NCT03103152). Participants were randomised to oral low dose (100 mg), standard dose (300 mg) aspirin or placebo and/or vitamin D3 (4000 IU) versus placebo in a 3 × 2 factorial RCT design with biopsy tissue Prolaris® testing. The primary endpoint was trial acceptance/entry rates. Secondary endpoints included feasibility of Prolaris® testing, 12-month disease re-assessment (imaging/biochemical/histological), and 12-month treatment adherence/safety. Disease progression was defined as any of the following (i) 50% increase in baseline PSA, (ii) new Prostate Imaging-Reporting and Data System (PI-RADS) 4/5 lesion(s) on multi-parametric MRI where no previous lesion, (iii) 33% volume increase in lesion size, or radiological upstaging to ≥T3, (iv) ISUP Grade Group upgrade or (v) 50% increase in maximum cancer core length. Results: Of 130 eligible patients, 104 (80%) accepted recruitment from seven sites over 12 months, of which 94 patients represented the per protocol population receiving treatment. Prolaris® testing was performed on 76/94 (81%) diagnostic biopsies. Twelve-month disease progression rate was 43.3%. Assessable 12-month treatment adherence in non-progressing patients to aspirin and vitamin D across all treatment arms was 91%. Two drug-attributable serious adverse events in 1 patient allocated to aspirin were identified. The study was not designed to determine differences between treatment arms. Conclusion: Recruitment of AS PCa patients into a multi-centre multi-arm placebo-controlled RCT of minimally-toxic adjunctive oral drug treatments with molecular biomarker profiling is acceptable and safe. A larger phase III study is needed to determine optimal agents, intervention efficacy, and outcome-associated biomarkers.

Thermal Strain During Open-Water Swimming Competition in Warm Water Environments.

Open-water swim racing in warm water is associated with significant physiological strain. However, existing international policy that governs safe participation during competition relies only on a fixed water temperature threshold for event cancellation and has an unclear biophysical rationale. The current policy does not factor other environmental factors or race distance, nor provide a stratification of risk (low, moderate, high, or extreme) prior to the threshold for cancellation. Therefore, the primary aim of this Perspectives article is to highlight considerations for the development of modernized warm-water competition policies. We highlight current accounts (or lack thereof) of thermal strain, cooling interventions, and performance in warm-water swimming and opportunities for advancement of knowledge. Further work is needed that systematically evaluate real-world thermal strain and performance during warm water competition (alongside reports of environmental conditions), novel preparatory strategies, and in-race cooling strategies. This could ultimately form a basis for future development of modernized policies for athlete cohorts that stratifies risk and mitigation strategies according to important environmental factors and race-specific factors (distance).

How university students perceive emergency management: A case for marketing emergency management.

OBJECTIVE: The purpose of this study was to determine if university students understood the differences between first responders and emergency management as awareness of the differences informs the individual's decision-making processes. DESIGN: Convenience sampling, mixed methods data collection with descriptive analysis and means testing. SETTING: US, Southeastern Conference University, during summer semester. PARTICIPANTS: 500 convenience sampled student volunteers. INTERVENTION: Convenience sampled, mixed-mode survey administered May to July 2017. MAIN OUTCOME MEASURES: Population sampling of a minimum of n = 372 (actual n = 500 obtained) surveys to achieve a 95 percent confidence level of p ≤ 0.05 ± 4.29 percent. RESULTS: 19.6 percent of the participants were able to associate response and recovery with emergency management. Word association with "Emergency Management" as the trigger word produced a 35.8 percent association with disasters and emergencies. 70.4 percent of the participants attended a university sponsored emergency preparedness course, but only 44.2 percent indicated they had received emergency preparedness training. CONCLUSIONS: There was a derivation of three issues: A lack of understanding in the differences between first responders and emergency management, a non-association of emergencies and disasters with emergency management, and a lack of understanding in what emergency preparedness training is. Results point to a need for further education on the duties and responsibilities of the emergency management profession. A form of information transfer that may be productive would be to administer an awareness campaign via social marketing. Further study is indicated, using a more rigorous sampling and analysis methodology.

Chronic pantothenic acid supplementation does not affect muscle coenzyme A content or cycling performance.

This study determined if supplementation with pantothenic acid (PA) for 16 weeks could increase skeletal muscle coenzyme A (CoASH) content and exercise performance. Trained male cyclists (n = 14) were matched into control or PA (6 g·day-1) groups. At 0, 4, 8, and 16 weeks, subjects performed an incremental time to exhaustion cycle with muscle biopsies taken prior to and following exercise. Prolonged PA supplementation did not change skeletal muscle CoASH and acetyl-CoA contents or exercise performance. Novelty: Supplementation with pantothenic acid for 16 weeks had no effect on skeletal muscle CoASH and acetyl-CoA content or exercise performance in trained male cyclists.

Spectrotemporal receptive fields in anesthetized cat primary auditory cortex are context dependent.

In order to investigate how the auditory scene is analyzed and perceived, auditory spectrotemporal receptive fields (STRFs) are generally used as a convenient way to describe how frequency and temporal sound information is encoded. However, using broadband sounds to estimate STRFs imperfectly reflects the way neurons process complex stimuli like conspecific vocalizations insofar as natural sounds often show limited bandwidth. Using recordings in the primary auditory cortex of anesthetized cats, we show that presentation of narrowband stimuli not including the best frequency of neurons provokes the appearance of residual peaks and increased firing rate at some specific spectral edges of stimuli compared with classical STRFs obtained from broadband stimuli. This result is the same for STRFs obtained from both spikes and local field potentials. Potential mechanisms likely involve release from inhibition. We thus emphasize some aspects of context dependency of STRFs, that is, how the balance of inhibitory and excitatory inputs is able to shape the neural response from the spectral content of stimuli.

The Impact of Individualizing Sodium Bicarbonate Supplementation Strategies on World-Class Rowing Performance.

Contemporary meta-analyses have generally demonstrated a positive effect of sodium bicarbonate (NaHCO3) supplementation on exercise performance. However, despite these claims, there is limited data on contrasting individualized and standardized timing of NaHCO3 ingestion prior to exercise to further enhance performance outcomes. Purpose: To determine whether NaHCO3 ingestion timing impacts 2,000-m rowing time-trial (TT) performance in elite-level rowers (Senior National team including Olympic/World Championships level) adhering to their own individualized pre-race strategies (e.g. nutrition, warm-up, etc.). Methods: Twenty three (n = 23) rowers across two research centers (using the exact same methods/protocols) completed three trials: NaHCO3 loading profile at rest to determine the individual's time-to-peak bicarbonate concentration [ HCO 3 - ], followed by two randomized 0.3 g·kgBM-1 NaHCO3 supplementation experimental trials conducted at different time points [consensus timing (CON): TT performed 60 min post-NaHCO3 ingestion; and individualized peak (IP): TT performed at the rower's individual peak [ HCO 3 - ] determined from the profiling trial post-NaHCO3 ingestion]. Results: There was a significant mean difference of +2.9 [± 0.4 mmol·L-1 HCO 3 - for IP vs. CON (95% CI 2.0 to 3.8 mmol·L-1); p = 0.02; d = 1.08] at pre warm-up, but not immediately prior to the TT (post warm-up). Performance times were significantly different between IP (367.0 ± 10.5 s) vs. CON (369.0 ± 10.3 s); p = 0.007; d = 0.15). Conclusions: The present study demonstrated a small but significant performance effect of an individualized NaHCO3 ingestion strategy. Similarities after warm-up between pre-TT sHCO 3 - values (CON ~ + 5.5 mmol·L-1; IP ~ + 6 mmol·L-1), however, would suggest this effect was not a result of any meaningful differences in blood alkalinity.

Optimisation and Validation of a Nutritional Intervention to Enhance Sleep Quality and Quantity.

BACKGROUND: Disturbed sleep may negatively influence physical health, cognitive performance, metabolism, and general wellbeing. Nutritional interventions represent a potential non-pharmacological means to increase sleep quality and quantity. OBJECTIVE: (1) Identify an optimal suite of nutritional ingredients and (2) validate the effects of this suite utilising polysomnography, and cognitive and balance tests. METHODS: The optimal and least optimal combinations of six ingredients were identified utilising 55 male participants and a Box-Behnken predictive model. To validate the model, 18 healthy, male, normal sleepers underwent three trials in a randomised, counterbalanced design: (1) optimal drink, (2) least optimal drink, or (3) placebo were provided before bed in a double-blinded manner. Polysomnography was utilised to measure sleep architecture. Cognitive performance, postural sway, and subjective sleep quality, were assessed 30 min after waking. RESULTS: The optimal drink resulted in a significantly shorter sleep onset latency (9.9 ± 12.3 min) when compared to both the least optimal drink (26.1 ± 37.4 min) and the placebo drink (19.6 ± 32.0 min). No other measures of sleep, cognitive performance, postural sway, and subjective sleep quality were different between trials. CONCLUSION: A combination of ingredients, optimised to enhance sleep, significantly reduced sleep onset latency. No detrimental effects on sleep architecture, subjective sleep quality or next day performance were observed.

Plasma Amino Acid Concentrations After the Ingestion of Dairy and Collagen Proteins, in Healthy Active Males.

Introduction: Recent evidence suggests that the consumption of essential amino acids (AA) and/or those abundantly present in collagen may have the capacity to influence the synthesis of new collagen in ligaments and tendons, when tissue perfusion is optimized (e.g., during exercise). However, little is currently known about the bioavailability of these AAs in blood after the consumption of various collagen and diary protein sources: such information is needed to develop potentially useful dietary and supplement intake strategies. Objectives: The aim of the current study was to characterize blood AA concentrations in response to consumption of collagen and dairy protein sources; specifically, maximum concentrations, the timing of maximum concentration, and total (area under the curve) exposure above baseline. Methods: A 20 g serve of various dairy and collagen proteins, and a 300 mL serve of bone broth were consumed by healthy, recreationally active males after an overnight fast. Blood samples were drawn every 20 min for a total of 180 min, for analysis of plasma AA concentrations. Total AA, essential AA and collagen specific AAs were analyzed for maximum concentration, timing of peak, and area under the curve. Results: In general, protein intake was associated with a similar increase in total and collagen specific AAs, except for collagen proteins being a superior source of glycine (683 ± 166 µmol/L) compared to 260 ± 65 µmol/L for dairy proteins (P < 0.0001), whilst dairy proteins were a superior source of leucine (267 ± 77 µmol/L) compared to 189 ± µmol/L for collagen proteins (P < 0.04). Although there were several differences in the bioavailability of hydrolysed compared to non-hydrolysed proteins, this only reached statistical significance within the dairy proteins, but not for collagen proteins. Conclusions: The intake of collagen proteins result in higher plasma peaks of glycine, whilst the intake of dairy proteins result in higher plasma peaks of leucine. This information may support further investigations, and identification of key AAs that may support exercise in the synthesis of collagen.