Kevin D Tipton

Kevin D Tipton
Durham University | DU · Department of Sport and Exercise Sciences

PhD

About

140
Publications
156,190
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
13,543
Citations
Additional affiliations
July 2010 - present
University of Stirling
April 2005 - June 2010
University of Birmingham
Position
  • Sr Lecturer
September 1997 - March 2005
University of Texas Medical Branch at Galveston
Position
  • Professor (Assistant)

Publications

Publications (140)
Article
Full-text available
The acute response of muscle protein synthesis (MPS) to resistance exercise and nutrition is often used to inform recommendations for exercise programming and dietary interventions, particularly protein nutrition, to support and enhance muscle growth with training. Those recommendations are worthwhile only if there is a predictive relationship betw...
Article
Full-text available
Background: The “leucine trigger” hypothesis was originally conceived to explain the post-prandial regulation of muscle protein synthesis (MPS). This hypothesis implicates the magnitude (amplitude and rate) of post-prandial increase in blood leucine concentrations for regulation of the magnitude of MPS response to an ingested protein source. Recent...
Article
Branched-chain amino acids (BCAA) are one of the most popular sports supplements, marketed under the premise that they enhance muscular adaptations. Despite their prevalent consumption among athletes and the general public, the efficacy of BCAA has been an ongoing source of controversy in the sports nutrition field. Early support for BCAA supplemen...
Article
Full-text available
Purpose Increasing protein intake during energy restriction (ER) attenuates lean body mass (LBM) loss in trained males. However, whether this relationship exists in trained females is unknown. This study examined the impact of higher compared to lower protein intakes (35% versus 15% of energy intake) on body composition in trained females during 2...
Article
Full-text available
Abstract Understanding human physiological responses to high‐fat energy excess (HFEE) may help combat the development of metabolic disease. We aimed to investigate the impact of manipulating the n‐3PUFA content of HFEE diets on whole‐body and skeletal muscle markers of insulin sensitivity. Twenty healthy males were overfed (150% energy, 60% fat, 25...
Article
Full-text available
Background: A detrimental consequence of diet-induced weight loss, common in athletes who participate in weight cutting sports, is muscle loss. Dietary omega-3 polyunsaturated fatty acids (n-3PUFA) exhibit a protective effect on the loss of muscle tissue during catabolic situations such as injury-simulated leg immobilization. This study aimed to in...
Article
Full-text available
Background: At rest, omission of breakfast lowers daily energy intake, but also lowers energy expenditure, attenuating any effect on energy balance. The effect of breakfast omission on energy balance when exercise is prescribed is unclear. Objectives: The aim of this study was to assess the effect on 24-h energy balance of omitting compared with...
Article
Aims: To characterize postprandial glucose flux after exercise in the fed versus overnight fasted-state and to investigate potential underlying mechanisms. Methods: In a randomized order, twelve men underwent breakfast-rest (BR; 3 h semi-recumbent), breakfast-exercise (BE; 2 h semi-recumbent before 60-min of cycling (50% peak power output) and o...
Article
Nighttime eating is often associated with a negative impact on weight management and cardiometabolic health. However, data from recent acute metabolic studies have implicated a benefit of ingesting a bedtime snack for weight management. The present study compared the impact of ingesting a milk snack containing either 10 (BS10) or 30 g (BS30) protei...
Article
Full-text available
Muscle protein breakdown (MPB) is an important metabolic component of muscle remodeling, adaptation to training, and increasing muscle mass. Degradation of muscle proteins occurs via the integration of three main systems—autophagy and the calpain and ubiquitin-proteasome systems. These systems do not operate independently, and the regulation is com...
Article
Full-text available
Carbohydrate (CHO) ingestion during exercise lasting less than three hours improves endurance exercise performance but there is still debate about the optimal dose. We utilised stable isotopes and blood metabolite profiles to further examine metabolic responses to CHO (glucose only) ingestion in the 20-64 g·h-1 range, and to determine the associati...
Article
Full-text available
Soccer players often experience eccentric exercise-induced muscle damage given the physical demands of soccer match-play. Since long chain n-3 polyunsaturated fatty acids (n-3PUFA) enhance muscle sensitivity to protein supplementation, dietary supplementation with a combination of fish oil-derived n-3PUFA, protein and carbohydrate may promote exerc...
Article
Full-text available
The ingestion of intact protein or essential amino acids (EAA) stimulates mechanistic target of rapamycin complex-1 (mTORC1) signaling and muscle protein synthesis (MPS) following resistance exercise. The purpose of this study was to investigate the response of myofibrillar-MPS to ingestion of branched-chain amino acids (BCAAs) only (i.e., without...
Article
Full-text available
The currently accepted amount of protein required to achieve maximal stimulation of myofibrillar protein synthesis (MPS) following resistance exercise is 20–25 g. However, the influence of lean body mass (LBM) on the response of MPS to protein ingestion is unclear. Our aim was to assess the influence of LBM, both total and the amount activated duri...
Article
Full-text available
Exceptional body composition changes attributed to collagen peptide supplementation and resistance training in older sarcopenic men - Volume 116 Issue 3 - Stuart M. Phillips, Kevin D. Tipton, Luc J. C. van Loon, Lex B. Verdijk, Douglas Paddon-Jones, Graeme L. Close
Article
Full-text available
Skeletal muscle is critical for human health. Protein feeding, alongside resistance exercise, is a potent stimulus for muscle protein synthesis (MPS) and is a key factor that regulates skeletal muscle mass (SMM). The main purpose of this narrative review was to evaluate the latest evidence for optimising the amino acid or protein source, dose, timi...
Article
Full-text available
Fish oil (FO) supplementation potentiates muscle protein synthesis (MPS) in response to a hyperaminoacidemic-hyperinsulinemic infusion. WhetherFOsupplementation potentiatesMPSin response to protein ingestion or when protein ingestion is combined with resistance exercise (RE) remains unknown. In a randomized, parallel group design, 20 healthy males...
Article
Full-text available
Purpose: Monitoring mood state is a useful tool for avoiding non-functional overreaching (NFOR). Brain derived neurotrophic factor (BDNF) is implicated in stress-related mood disorders. The purpose of the present study was to investigate the impact of intensified training-induced mood disturbance on plasma BDNF concentrations at rest and in respon...
Article
Full-text available
Nutrition is one method to counter the negative impact of an exercise-induced injury. Deficiencies of energy, protein and other nutrients should be avoided. Claims for the effectiveness of many other nutrients following injuries are rampant, but the evidence is equivocal. The results of an exercise-induced injury may vary widely depending on the na...
Chapter
Protein plays an integral role in the growth and repair of tissues, making it an important part of the human diet. Protein requirements are designed to prevent deficiencies; however, athletes look to use protein as a tool for increasing adaptations to training. Therefore, we suggest that protein recommendations are more useful than proteins require...
Conference Paper
Full-text available
Purpose: The ingestion of carbohydrate (CHO) during exercise (EX) has repeatedly been reported to improve endurance EX performance and extend EX capacity. Ingestion rates between 20-64g.h-1 have consistently led to the greatest performance gains compared to a 0g•h-1 control. Performance gains tend to diminish with ingestion rates above 40-60g•h-1 w...
Article
Full-text available
In an investigator-blind, randomised cross-over design, male cyclists (mean±SD) age 34.0 (± 10.2) years, body mass 74.6 (±7.9) kg, stature 178.3 (±8.0) cm, peak power output (PPO) 393 (±36) W, and VO2max 62 (±9) ml·kg-1·min-1 training for >6h/wk for >3y (n=20) completed four experimental trials. Each trial consisted of a 2h constant load ride at 95...
Article
Full-text available
Background. Adequate protein ingestion-mediated stimulation of myofibrillar protein synthesis (MPS) is required to maintain skeletal muscle mass. It is currently unknown what per meal protein intake is required to maximally stimulate the response in older men and whether it differs from that of younger men. Methods. We retrospectively analyzed data...
Article
Objective The effects of RT on muscle mass, strength, and insulin sensitivity are well established, but the underlying mechanisms are only partially understood. The main aim of this study was to investigate whether RT induces changes in endothelial enzymes of the muscle microvasculature, which would increase NO bioavailability and could contribute...
Article
Full-text available
The adaptive response to training is determined by the combination of the intensity, volume and frequency of the training. Various periodized approaches to training are used by aquatic sports athletes to achieve performance peaks. Nutritional support to optimize training adaptations should take periodization into consideration, i.e. nutrition shoul...
Article
The aim of this study was to examine changes in the lipid profile of red blood cells and muscle tissue along with muscle expression of anabolic signalling proteins in human skeletal muscle. Following a 2-week control period ten healthy male participants consumed 5 g d−1 of fish oil (FO) for 4-weeks. Muscle biopsies and venous blood samples were col...
Article
Full-text available
The aging process is associated with gradual and progressive loss of muscle mass along with lowered strength and physical endurance. This condition, sarcopenia, has been widely observed with aging in sedentary adults. Regular aerobic and resistance exercise programs have been shown to counteract most aspects of sarcopenia. In addition, good nutriti...
Article
Recent in vitro and in vivo experimental observations suggest that improvements in insulin sensitivity following endurance training are mechanistically linked to increases in muscle oxidative capacity, intramuscular triglyceride (IMTG) utilization during endurance exercise and increases in the content of the lipid droplet-associated perilipin 2 (PL...
Article
Full-text available
Many athletes use dietary supplements, with use more prevalent among those competing at the highest level. Supplements are often self-prescribed and their use is likely to be based on an inadequate understanding of the issues at stake. Supplementation with essential micronutrients may be useful when a diagnosed deficiency cannot be promptly and eff...
Article
Relative to essential amino acids (EAAs), carbohydrate (CHO) ingestion stimulates a delayed response of net muscle protein balance (NBAL). We investigated if staggered ingestion of CHO and EAA would superimpose the response of NBAL following resistance exercise, thus resulting in maximal anabolic stimulation. Eight recreationally trained subjects c...
Conference Paper
Recent studies have examined dose response relationships from ingesting a carbohydrate (CHO) drink on exercise performance, with optimal performance from single source CHO suggested to occur at doses around 60 g.h-1. However, the evidence for a dose-response in the 20-64 g.h-1 range is still unclear. We aimed to investigate the dose-response of CHO...
Article
The intake of whey, compared with casein and soy protein intakes, stimulates a greater acute response of muscle protein synthesis (MPS) to protein ingestion in rested and exercised muscle. We characterized the dose-response relation of postabsorptive rates of myofibrillar MPS to increasing amounts of whey protein at rest and after exercise in resis...
Article
Full-text available
The present study examined whether a high protein diet prevents the attenuated leukocyte redistribution in response to acute exercise caused by a large volume of high-intensity exercise training. Eight cyclists (VO2max: 64.2 ± 6.5 mL kg(-1)·min(-1)) undertook two separate weeks of high-intensity training while consuming either a high protein diet (...
Article
Full-text available
Skeletal muscle hypertrophy is a beneficial adaptation for many individuals. The metabolic basis for muscle hypertrophy is the balance between the rates of muscle protein synthesis (MPS) and muscle protein breakdown (MPB), i.e. net muscle protein balance (NMPB = MPS - MPB). Resistance exercise potentiates the response of muscle to protein ingestion...
Article
Full-text available
Injuries are an unavoidable aspect of participation in physical activity. Nutrition is important for optimal wound healing and recovery, but little information about nutritional support for injuries exists. Immediately following injury, wound healing begins with an inflammatory response. Excessive anti-inflammatory measures may impair recovery. Man...
Article
Nutrition plays a key role in allowing the numerous training hours to be translated into useful adaptive responses of various tissues in the individual athlete. Research over the last decade has shown many examples of the impact of dietary interventions to modulate the skeletal muscle adaptive response to prolonged exercise training. Proper nutriti...
Book
Diet adaptation and athletic performance – what is the connection? Regular training and adequate nutrition are key factors in modulating exercise performance: Optimal performance requires a healthy diet adapted to the specific demands of the individual athlete's training and competition. Research has shown an impact of dietary intervention on the m...
Article
Intramuscular triglyceride (IMTG) utilization is enhanced by endurance training (ET) and is linked to improved insulin sensitivity. This study first investigated the hypothesis that ET-induced increases in net IMTG breakdown and insulin sensitivity are related to increased expression of perilipin 2 (PLIN2) and perilipin 5 (PLIN5). Secondly, we hypo...
Article
High intensity interval training (HIT) has been proposed as a time efficient alternative to endurance training (ET) for increasing skeletal muscle oxidative capacity and improving certain cardiovascular functions. In this study we sought to make the first comparisons of the structural and endothelial enzymatic changes in skeletal muscle microvessel...
Article
Full-text available
We have previously shown that the aminoacidemia caused by the consumption of a rapidly digested protein after resistance exercise enhances muscle protein synthesis (MPS) more than the amino acid (AA) profile associated with a slowly digested protein. Here, we investigated whether differential feeding patterns of a whey protein mixture commencing be...
Article
Full-text available
We examined whether exercise-induced lymphocytosis and lymphocytopenia are impaired with high-intensity training. Eight trained cyclists (VO(2max) = 64.2 ± 6.5 mL · kg(-1) · min(-1)) undertook 1 wk of normal-intensity training and a second week of high-intensity training. On day 7 of each week, participants performed a cycling task, consisting of 1...
Article
The lipid droplet (LD)-associated protein perilipin 2 (PLIN2) appears to colocalize with LDs in human skeletal muscle fibres, although the function of PLIN2 in the regulation of intramuscular triglyceride (IMTG) metabolism is currently unknown. Here we investigated the hypothesis that the presence of PLIN2 in skeletal muscle LDs is related to IMTG...
Article
Non-technical summary A single bout of exercise stimulates the production of new muscle proteins. Furthermore, ingesting protein in close proximity to exercise enhances the metabolic response. Long-term exercise training promotes muscle adaptation, and the mode of exercise performed determines the type of proteins that are made. To date, the types...
Article
Full-text available
To investigate the mechanisms underpinning modifications in glucose homeostasis and insulin sensitivity 24 h after a bout of resistance exercise (RE) with or without protein ingestion. Twenty-four healthy males were assigned to a control (CON; n = 8), exercise (EX; n = 8) or exercise plus protein condition (EX+PRO; n = 8). Muscle biopsy and blood s...
Article
The purpose of the present study was to examine the effect of increased protein intake on short-term decrements in endurance performance during a block of high-intensity training. Trained male cyclists (VO(2max) = 64.2 ± 6.5 mL·kg(-1)·min(-1)) completed two 3-wk trials both divided equally into normal (NOR), intensified (INT), and recovery (REC) tr...
Article
Full-text available
Athletes and exercisers have utilised high-protein diets for centuries. The objective of this review is to examine the evidence for the efficacy and potential dangers of high-protein diets. One important factor to consider is the definition of a 'high-protein diet'. There are several ways to consider protein content of a diet. The composition of th...
Article
Both micro and macrovascular adaptations contribute to the mechanisms by which reduced physical activity increases the risk for cardiovascular disease and insulin resistance. In a parallel abstract,1 the authors report that 6 weeks of high-intensity interval training (HIT) improves insulin sensitivity. Here the authors aim to investigate whether ch...
Article
Physically trained individuals exhibit high rates of whole-body fat oxidation and elevated insulin sensitivity. High-intensity interval training (HIT) has been suggested to induce similar metabolic adaptations in a more time efficient manner than traditional endurance training. To widen this claim the authors aimed to investigate whether 6 weeks of...
Article
THE STIMULATION OF MUSCLE PROTEIN SYNTHESIS IS RELIANT ON THE ADEQUATE AVAILABILITY OF AMINO ACID (AA) PRECURSORS. THE INCREASE IN CIRCULATING AA CONCENTRATIONS IN THE BLOOD SERVES AS A SIGNAL TO INITIATE SYNTHETIC PROCESSES. A SUFFICIENT INCREASE IN BLOOD AA IS REQUIRED TO OVERCOME A CONCENTRATION GRADIENT THAT NORMALLY FAVORS THE INTRACELLULAR SP...
Article
Full-text available
Injuries are an unavoidable aspect of participation in physical activity. Little information about nutritional support for injuries exists. Immediately following injury, wound healing begins with an inflammatory response. Excessive anti-inflammatory measures may impair recovery. Many injuries result in limb immobilization. Immobilization results in...
Article
The purpose of this study was to examine the role of branched-chain amino acid (BCAA) supplementation during recovery from intense eccentric exercise. Twenty-four non-weight-trained males were assigned to one of two groups: one group (supplementary, SUP) ingested BCAA beverages (n = 12); the second group (placebo, PLA) ingested artificially flavore...
Article
The aim of this study was to determine whether adding protein to a CHO beverage would improve late-exercise cycle time-trial performance over CHO alone. Furthermore, we examined the effects of coingesting protein with CHO during exercise on postexercise markers of sarcolemmal disruption and the recovery of muscle function. In a double-blind, crosso...
Article
Full-text available
To examine the influence of dietary protein on lean body mass loss and performance during short-term hypoenergetic weight loss in athletes. In a parallel design, 20 young healthy resistance-trained athletes were examined for energy expenditure for 1 wk and fed a mixed diet (15% protein, 100% energy) in the second week followed by a hypoenergetic di...
Article
Several nutritional strategies have been used in cycling to improve performance. Carbohydrate feeding during exercise has been shown to be effective, but recent studies have suggested that recommendations may have to be adjusted to take into account recent findings. Protein co-ingested with carbohydrate during exercise has received a lot of recent...
Article
Leucine is known to stimulate muscle protein synthesis and anabolism. However, evidence for the efficacy of additional leucine to enhance the response of muscle anabolism to resistance exercise and protein ingestion is unclear. Thus, we investigated the response of net muscle protein balance to ingestion of additional leucine with protein in associ...
Article
We examined the impact of an acute bout of resistance-type exercise on mixed muscle protein synthesis in the fed state. After a standardized breakfast, 10 untrained males completed a single, unilateral lower-limb resistance-type exercise session. A primed, continuous infusion of l-[ring-C6]phenylalanine was combined with muscle biopsy collection fr...
Article
To evaluate the efficacy of using combined glucose and fructose (GF) ingestion as a means to stimulate short-term (4 h) postexercise muscle glycogen synthesis compared to glucose only (G). On two separate occasions, six endurance-trained men performed an exhaustive glycogen-depleting exercise bout followed by a 4-h recovery period. Muscle biopsy sa...
Article
Nutrient intake before, during, and after training will influence the adaptations that occur in response to the training stimulus. The influence of protein on training adaptations is receiving increasing attention from researchers. Methodological issues should be carefully considered when evaluating evidence of nutritional influence on training ada...
Article
Full-text available
Muscle mass is critical for athletic performance and, perhaps more importantly for most, health and survival. The metabolic basis for a change in muscle mass is an increase in net muscle protein balance (termed NBAL). NBAL is the difference between MPS (muscle protein synthesis) and MPB (muscle protein breakdown). Thus an increase in MPS and/or a d...