Lawrence L Spriet

Lawrence L Spriet
University of Guelph | UOGuelph · Department of Human Health and Nutritional Sciences (HHNS)

PhD
University Professor Emeritus, Human Health & Nutritional Sciences, University of Guelph

About

364
Publications
178,042
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16,299
Citations
Additional affiliations
January 1986 - present
University of Guelph
Position
  • Professor & Chair

Publications

Publications (364)
Article
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This study recorded the dietary intakes of young male ice hockey players (10–13 year (yr)) for 3 consecutive days while participating in a 5-day summer hockey camp. Players were categorized as older children (OC, n = 10; 10.7 ± 0.2 yr; 37.1 ± 1.5 kg; 147.9 ± 2.1 cm) and young adolescents (YA, n = 10; 12.9 ± 0.1 yr; 45.2 ± 1.5 kg; 157.0 ± 2.4 cm). P...
Article
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This study estimated the daily energy intake (EI) and energy expenditure (TDEE) in female varsity rugby union players during a weekly training/game cycle. Fifteen (nine forwards, six backs) players (20.5 ± 0.4 y, 167.1 ± 1.8 cm, 74.9 ± 2.9 kg) were monitored for a 7-day period (one fitness, two heavy training, one light training, one game, and two...
Article
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Purpose The purposes of this study were to quantify the external load for female and male varsity ice hockey players during regular season games using a local positioning system (LPS), compare LPS-derived external load between sexes and positions, and compare skating distances in absolute and relative speed zones. Methods Data were collected for 2...
Article
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This study determined the reliability and validity of a Kinexon local positioning system (LPS) for measuring external load in ice hockey players during an on-ice session. Fourteen ice hockey players (25.1 y, 78.6 kg, 176.9 cm) wore two LPS sensors to examine the inter-sensor reliability of the LPS during an on-ice session, and LPS speed and acceler...
Article
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PurposeThis randomized, double-blind, crossover study examined the effects of mouth-rinsing (MR) with a carbohydrate (CHO) vs. a placebo (PLA) solution on external and internal loads in hydrated ice hockey players during regulation and overtime (OT) periods of an on-ice scrimmage.Methods Twelve skilled male hockey players (22.6 [3.4] years, 178.9 [...
Article
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Purpose: The purpose of this study was to quantify the internal load of male varsity ice hockey players, using both sessional rating of perceived exertion (sRPE) and the heart rate-derived physiological measure of training impulse (TRIMP), during training sessions and competitions throughout an entire season. Methods: Twenty-seven male varsity i...
Preprint
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This study examined if acute dietary nitrate supplementation (140 mL beetroot juice, BRJ) would reduce oxygen consumption (V̇O 2 ) during cycling at power outputs of 50 and 70% maximal oxygen consumption in 14 well-trained female Canadian University Ringette League athletes. BRJ had no effect on V̇O 2 or heart rate but significantly reduced ratings...
Article
This study quantified internal load, using sessional rating of perceived exertion (sRPE) and heart-rate derived training impulse (TRIMP), of female varsity ice hockey players throughout a season. Twenty-four female (19.8±1.4 yr, 68.0±6.9 kg) varsity ice hockey players participated in this prospective cohort study. Internal load was captured using s...
Article
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Muscle glycogen is the main substrate during high-intensity exercise and large reductions can occur after relatively short durations. Moreover, muscle glycogen is stored heterogeneously and similarly displays a heterogeneous and fiber-type specific depletion pattern with utilization in both fast- and slow-twitch fibers during high-intensity exercis...
Article
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Bigg, JL, Gamble, ASD, and Spriet, LL. Internal physiological load measured using training impulse in varsity men's and women's ice hockey players between game periods. J Strength Cond Res XX(X): 000-000, 2021-This study quantified internal load in male and female ice hockey players throughout a season, with comparisons between game periods and mat...
Article
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Physiological strain during exercise is increased by mild dehydration (~1-3% body mass loss). This response may be sex-dependent but there are no direct comparative data in this regard. This review aimed to develop a framework for future research by exploring the potential impact of sex on thermoregulatory and cardiac strain associated with exercis...
Article
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This study examined the energy, macronutrient, and micronutrient intakes of female ice hockey players over a 7-d period including game, practice, and rest days. Twenty-three female varsity players (19.0 ± 1.1 yr, 167.1 ± 6.5 cm, 67.0 ± 8.0 kg) volunteered for the study. Average total daily energy expenditure (TDEE) was estimated over the 7-day peri...
Article
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This study used wearable Global Positioning System (GPS) microtechnology with individualized speed thresholds to examine external training demands in 29 female varsity rugby union athletes during competitive season practices. Players were categorized as forwards or backs and observed during fitness, game-based, or skill training days (FT/GT/ST). Gl...
Article
High-intensity eccentric exercise can lead to muscle damage and weakness. The ‘repeated bout effect’ (RBE) can attenuate these impairments when performing a subsequent bout. The influence of eccentric exercise-induced muscle damage on low-frequency force production is well-characterized; however, it is unclear how eccentric exercise and the RBE aff...
Article
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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 bio...
Article
High-intensity unaccustomed eccentric contractions result in weakness and power loss because of fatigue and muscle damage. Through the repeated bout effect (RBE), adaptations occur, then damage and weakness are attenuated following a subsequent bout. However, it is unclear whether the RBE protects peak power output. We investigated the influence of...
Article
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An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Article
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The continual supply of ATP to the fundamental cellular processes that underpin skeletal muscle contraction during exercise is essential for sports performance in events lasting seconds to several hours. Because the muscle stores of ATP are small, metabolic pathways must be activated to maintain the required rates of ATP resynthesis. These pathways...
Article
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Despite the emerging evidence of adverse consequences and interaction with doping substances, dietary supplements (DS) are commonly used by many Canadians. The purpose of this study was to evaluate the patterns and determinants of current DS use among non-athlete students at a Canadian university using a cross-sectional approach. Of the 475 partici...
Article
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The effects of mild dehydration during ice hockey are well-studied in males but not females. In a randomized, crossover design, 11 female varsity hockey players drank no fluid (1.7% ± 0.3% body mass loss) or water to maintain hydration during simulated-hockey exercise. Core temperature (P < 0.01) and perceived fatigue (P = 0.02) were higher and spr...
Article
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Omega‐3 polyunsaturated fatty acids (PUFAs) have unique properties purported to influence several aspects of metabolism, including energy expenditure and protein function. Supplementing with n‐3 PUFAs may increase whole‐body resting metabolic rate (RMR), by enhancing Na+/K+ ATPase (NKA) activity and reducing the efficiency of sarcoplasmic reticulum...
Article
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Introduction: In skeletal muscle, the Na/K ATPase (NKA) plays essential roles in processes linked to muscle contraction, fatigue, and energy metabolism; however, very little information exists regarding the regulation of NKA activity. The scarcity of information regarding NKA function in skeletal muscle likely stems from methodological constraints...
Article
Bigg, JL, Gamble, ASD, Vermeulen, TF, Bigg, LM, and Spriet, LL. Sweat loss and fluid intake of female varsity ice hockey players during on-ice practices and games. J Strength Cond Res XX(X): 000-000, 2019-Sweat losses of ∼1.5-2% body mass (BM) during exercise impairs athletic performance in stop and go sports such as ice hockey. The study examined...
Article
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Purpose: To determine the effects of low-dose caffeine supplementation (3 mg/kg body mass) consumed 1 h before the experiment on rating of perceived exertion (RPE), skills performance (SP), and physicality in male college ice hockey players. Methods: Using a double-blind, placebo-controlled, randomized crossover experimental design, 15 college i...
Article
This study examined the independent effects of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acid supplementation on resting metabolic rate (RMR) and substrate oxidation in young healthy females and males. EPA or DHA supplementation had no effect on RMR and substrate oxidation in males, while DHA reduced RMR by ∼7% (p < 0.01) in females. In conc...
Article
Over the last decade there has been substantial interest in the health and athletic performance benefits associated with acute and chronic dietary nitrate (NO 3 – ) supplementation. Dietary NO 3 – , commonly found in leafy green and root vegetables, undergoes sequential reduction to nitrite and nitric oxide (NO) via the enterosalivary circulation....
Article
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Purpose: This study tested whether CHO intake during a 2-h rest between exercise bouts improved performance in the subsequent bout. Methods: In a randomized, single-blinded, crossover design, 10 recreationally-active participants (23 ± 4 yr, 70.8 ± 6.6 kg, VO2peak:47.0 ± 5.4 mL O2·min-1·kg body mass-1) arrived at the lab post-prandial and comple...
Article
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Several previous studies have reported performance decrements in team sport athletes that dehydrated ~1.5-2% of their body mass (BM) through sweating. This study measured on-ice sweat loss, fluid intake, sodium balance, and carbohydrate (CHO) intake of 77 major junior (JR) (19 ± 1 yr), 60 American Hockey League (AHL) (24 ± 4 yr), and 77 National Ho...
Article
This study measured sweat losses, voluntary fluid intake, sodium balance, and carbohydrate intake of female ice hockey players during on-ice practices at the Olympic, varsity, and recreational levels. Testing was conducted on 25 Canadian Olympic players, 21 varsity, and 21 recreational players. The average sweat rate for the Olympic players (0.99±0...
Article
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Fish oil (FO) supplementation in humans results in the incorporation of omega-3 fatty acids (FAs) eicosapentaenoic acid (EPA; C20:5) and docosahexaenoic acid (DHA; C20:6) into skeletal muscle membranes. However, despite the importance of membrane composition in structure-function relationships, a paucity of information exists regarding how differen...
Article
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This study investigated the effects of acute and chronic beetroot juice (BRJ) supplementation on submaximal exercise oxygen uptake (VO2 ), time trial (TT) performance, and contractile properties of the plantar flexors in females. Study 1: Using a double blind, randomized, crossover design, 12 recreationally active females using hormonal contracepti...
Article
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During play, ice hockey goaltenders routinely dehydrate through sweating and lose ≥2% body mass, which may impair thermoregulation and performance. Purpose: This randomized, crossover study examined the effects of mild dehydration on goaltender on-ice thermoregulation, heart rate, fatigue, and performance. Methods: Eleven goaltenders played a 7...
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Objective: To develop and implement a prospective varsity athlete surveillance system to identify injury and illness trends in a multisport varsity-level university setting. Design: Longitudinal prospective surveillance study. Setting: Varsity-level sport program at the University of Guelph, Guelph, ON, Canada. Participants: Athletic therapi...
Article
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Objective: To examine the feasibility and preliminary impact of a home-based obesity prevention intervention among Canadian families. Methods: Families with children 1.5-5 years of age were randomized to one of three groups: (1) four home visits (HV) with a health educator, emails, and mailed incentives (4HV; n = 17); (2) two HV, emails, and mai...
Article
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Nutrition usually makes a small but potentially valuable contribution to successful performance in elite athletes, and dietary supplements can make a minor contribution to this nutrition program. Nonetheless, supplement use is widespread at all levels of sport. Products described as supplements target different issues, including the management of m...
Article
Full-text available
Nutrition usually makes a small but potentially valuable contribution to successful performance in elite athletes, and dietary supplements can make a minor contribution to this nutrition programme. Nonetheless, supplement use is widespread at all levels of sport. Products described as supplements target different issues, including (1) the managemen...
Article
Full-text available
There has been recent interest in the ergogenic effects of caffeine delivered in low doses (~ 200 mg or ~ 3 mg/kg body mass) and administered in forms other than capsules, coffee and sports drinks, including chewing gum, bars, gels, mouth rinses, energy drinks and aerosols. Caffeinated chewing gum is absorbed quicker through the buccal mucosa compa...
Article
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Resisted sprint training (RST) is commonly used for performance enhancement in athletics and team sports to develop acceleration ability. Evidence suggests that RST may be effective as a short-term intervention to improve successive sprints. While these improvements have been measured in team sport athletes, limited research has considered the acut...
Article
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Ischemic pre-conditioning (IPC) was initially developed to protect the myocardium from ischemia through altered cardiocyte metabolism. Due to the observed effects on metabolism and oxygen kinetics, IPC gained interest as a potential ergogenic aid in sport. Limited research evaluating the effects of IPC on maximal short-duration activities has been...
Article
This study determined whether ingesting a carbohydrate-electrolyte solution (CES) vs. progressive dehydration affected skeletal muscle glycogen use and performance in ice hockey players during simulated ice hockey exercise comprised of 3 active “periods”. Seven males (21.3±0.3 years, 184.7±1.2 cm, 84.2±3.9 kg, and 49.6±1.8 mL·kg−1·min−1) performed...
Article
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TBC1 domain family member 1 (TBC1D1), a Rab GTPase-activating protein and paralogue of Akt substrate of 160 kDa (AS160), has been implicated in both insulin- and 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase/IMP cyclohydrolase (AICAR)-mediated glucose transporter type (GLUT4) translocation. However, the role of TBC1D1 in contracti...
Article
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The mechanistic target of rapamycin (mTOR) is a central mediator of protein synthesis in skeletal muscle. We utilized immunofluorescence approaches to study mTOR cellular distribution and protein-protein co-localisation in human skeletal muscle in the basal state as well as immediately, 1 and 3 h after an acute bout of resistance exercise in a fed...
Article
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During exercise, the supply of adenosine triphosphate (ATP) is essential for the energy-dependent processes that underpin ongoing contractile activity. These pathways involve both substrate-level phosphorylation, without any need for oxygen, and oxidative phosphorylation that is critically dependent on oxygen delivery to contracting skeletal muscle...
Article
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Purpose: To examine the effects of 7-d of beetroot juice (BRJ) supplementation on SkM contractile characteristics and function. Methods: Recreationally active males (n=8) underwent transcutaneous electrical muscle stimulation of the vastus lateralis for evaluation of contractile characteristics before (pre) and after (post) 7-d of BRJ supplement...
Article
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Fish oil (FO) has been shown to have beneficial effects in the body via incorporation into the membranes of many tissues. It has been proposed that omega-3 fatty acids in FO may increase whole body resting metabolic rate (RMR) and fatty acid (FA) oxidation in human subjects, but the results to date are equivocal. The purpose of this study was to in...
Article
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This study determined whether mild dehydration influenced skeletal muscle glycogen use, core temperature or performance during high-intensity, intermittent cycle-based exercise in ice hockey players vs. staying hydrated with water. Eight males (21.6 ± 0.4 yr, 183.5 ± 1.6 cm, 83.9 ± 3.7 kg, 50.2 ± 1.9 mL·kg(-1)·min(-1)) performed two trials separate...
Article
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Food preferences and dietary habits are heavily influenced by taste perception. There is growing interest in characterizing taste preferences based on genetic variation. Genetic differences in the ability to perceive key tastes may impact eating behavior and nutritional intake. Therefore, increased understanding of taste biology and genetics may le...
Article
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The aim of the present study was to assess if low and moderate doses of caffeine delivered in a carbohydrate-electrolyte solution (CES) late in exercise improved time-trial (TT) performance. Fifteen (11 male, 4 female) cyclists (age, 22.5 ± 0.9 years; body mass, 69.3 ± 2.6 kg; peak oxygen consumption, 64.6 ± 1.9 mL·min(-1)·kg(-1)) completed 4 doubl...
Article
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Considerable evidence supports an association between fatty acid desaturase 2 (FADS2) polymorphisms and the efficiency of converting alpha-linolenic acid (ALA) into eicosapentaenoic acid (EPA) via the desaturation-elongation pathway. However, ALA conversion into EPA represents only 1 of the metabolic fates for this essential fatty acid, as ALA is a...
Article
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Scope: Increased consumption of fish oils rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) is associated with improved cardiometabolic health and inflammatory status; however, age-related responses remain poorly described. Methods and results: In a placebo-controlled study, healthy young and older men consumed 5 fish oil capsul...
Article
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Critical among the changes that occur with aging are decreases in muscle mass and metabolic rate and an increase in fat mass. These changes may predispose older adults to chronic disease and functional impairment; ultimately resulting in a decrease in the quality of life. Research has suggested that long chain omega-3 fatty acids, found predominant...
Data
REB Approval Letter. (DOCX)