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result(s) for
"Sharp, Rick L."
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Comparative effectiveness of aerobic, resistance, and combined training on cardiovascular disease risk factors: A randomized controlled trial
2019
Although exercise has well-documented health benefits on cardiovascular disease (CVD), the benefit of combination exercise on CVD risk factors in individuals with elevated risk has not been fully elucidated. We compared the effects of aerobic, resistance, and a combination of both aerobic and resistance training on CVD risk factors including peripheral and central BP, cardiorespiratory fitness (CRF), muscular strength, body composition, blood glucose and lipids. Sixty-nine adults (58±7 years) with an elevated blood pressure or hypertension, overweight/obesity, and sedentary lifestyle were randomized to one of the three 8-week exercise programs or a non-exercise control group. Participants in all three exercise groups had an equal total exercise time, 3 days/week (aerobic: 60 minutes/session vs. resistance: 60 minutes/session vs. combination: aerobic 30 minutes/session plus resistance 30 minutes/session). Combined training provided significant reductions in peripheral (-4 mmHg) and central diastolic BP (-4 mmHg), increase in CRF (4.9 ml/kg/min), increase in upper (4 kg) and lower (11 kg) body strength, and increase in lean body mass (0.8 kg) (p <0.05). Aerobic training only increased CRF (7.7 ml/kg/min), and reduced body weight (-1.0 kg) and fat mass (-0.9 kg) (p <0.05). Resistance training only increased lower body strength (13 kg) and reduced waist circumference (-1.7 cm) (p <0.05). However, neither aerobic or resistance training alone showed significant reductions in BP (p>0.05). Furthermore, a composite score of CVD risk factors indicated a greater reduction with combination training compared to the control group. In conclusion, among individuals at an increased risk for CVD, as little as 8-weeks of combined training may provide more comprehensive CVD benefits compared to time-matched aerobic or resistance training alone.
Journal Article
Seasonal changes in physiological and psychological parameters of stress in collegiate swimmers
2023
To investigate the seasonal changes in physiological and psychological parameters of stress in collegiate swimmers. Fifteen NCAA Division I swimmers (8 men) participated in a tethered anaerobic swim test to determine physiological responses in an ecologically-relevant, graded exercise test. Wisconsin Upper Respiratory Symptom Survey (WURSS-21), Activation-Deactivation Adjective Check List (AD-ACL), Daily Analysis of Life Demands of Athletes (DALDA), and Pittsburgh Sleep Quality Index were assessed at post-season in April (V
1
), the end of off-season in June (V
2
), and pre-season in October (V
3
). The percent change was determined from V
2
–V
1
(off-season phase), V
3
–V
2
(pre-season phase), V
1
–V
3
(in-season phase). Spearman’s rho correlation was used to examine associations between change in physiological and psychological outcomes. All data results showed a better swim performance occurred at V
2
. Men tended to have faster speed (
p
= 0.07) in fewer strokes (
p
= 0.10) and greater work per stroke (
p
= 0.10) at V
2
than V
1
. Women were faster during V
2
compared to V
1
(
p
= 0.02) and V
3
(
p
= 0.05). Women had fewer strokes (
p
= 0.02) and greater work per stroke (
p
= 0.01) at V
2
compared to V
3
. Women had the lowest HR and lactate concentration at V
3
compared to other visits (
p
< 0.05). During the in-season phase, swim speed decreased the greatest extent and stress sources and symptoms assessed by DALDA had greatest elevation (
p
< 0.05). An increased in stress sources and symptoms assessed by DALDA was associated with an increase in upper respiratory illness from WURSS-21 (
rho
= 0.44,
p
= 0.009), being less energetic (
rho
= − 0.35,
p
= 0.04) and greater tension state (
rho
= 0.49,
p
= 0.003; AD-ACL), and a decrease in swim speed (
rho
=− 0.38,
p
= 0.03). Swim performance peaked at off-season when psychological stress was at its lowest. The relationship between DALDA scores with psychological parameters and swim performance suggested physiological and psychological parameters of stress is an important aspect to avoid overtraining when approaching high swim performance.
Journal Article
Adenosine-5'-triphosphate (ATP) supplementation improves low peak muscle torque and torque fatigue during repeated high intensity exercise sets
by
Fuller, John C
,
Sharp, Rick L
,
Rathmacher, John A
in
Adenosine
,
Adenosine triphosphate
,
Adenosine-5’-triphosphate
2012
Background
Intracellular concentrations of adenosine-5’-triphosphate (ATP) are many times greater than extracellular concentrations (1–10 m
M
versus 10–100 n
M
, respectively) and cellular release of ATP is tightly controlled. Transient rises in extracellular ATP and its metabolite adenosine have important signaling roles; and acting through purinergic receptors, can increase blood flow and oxygenation of tissues; and act as neurotransmitters. Increased blood flow not only increases substrate availability but may also aid in recovery through removal of metabolic waste products allowing muscles to accomplish more work with less fatigue. The objective of the present study was to determine if supplemental ATP would improve muscle torque, power, work, or fatigue during repeated bouts of high intensity resistance exercise.
Methods
Sixteen participants (8 male and 8 female; ages: 21–34 years) were enrolled in a double-blinded, placebo-controlled study using a crossover design. The participants received either supplemental ATP (400 mg/d divided into 2 daily doses) or placebo for 15 d. After an overnight fast, participants underwent strength and fatigue testing, consisting of 3 sets of 50 maximal knee extensions performed on a Biodex® leg dynamometer.
Results
No differences were detected in high peak torque, power, or total work with ATP supplementation; however, low peak torque in set 2 was significantly improved (p < 0.01). Additionally, in set 3, a trend was detected for less torque fatigue with ATP supplementation (p < 0.10).
Conclusions
Supplementation with 400 mg ATP/d for 15 days tended to reduce muscle fatigue and improved a participant’s ability to maintain a higher force output at the end of an exhaustive exercise bout.
Journal Article
Comparison of availability and plasma clearance rates of β-hydroxy-β-methylbutyrate delivery in the free acid and calcium salt forms
2015
β-Hydroxy-β-methylbutyrate (HMB), a leucine metabolite, has long been supplemented as a Ca salt (Ca-HMB) to increase strength and performance gains with exercise and to reduce recovery time. Recently, the free acid form of HMB (HMB-FA) has become commercially available in capsule form (gelcap). The current study was conducted to compare the bioavailability of HMB using the two commercially available capsule forms of HMB-FA and Ca-HMB. We also compared the pharmacokinetics of each form when administered mixed in water. Ten human subjects (five male and five female) were studied in a randomised crossover design. There was no significant sex by treatment interaction for any of the pharmacokinetic parameters measured. HMB-FA administered in capsules was more efficient than Ca-HMB capsule at HMB delivery with a 37 % increase in plasma clearance rate (74·8 (sem 4·0) v. 54·5 (sem 3·2) ml/min, P<0·0001) and a 76 % increase in peak plasma HMB concentration (270·2 (sem 17·8) v. 153·9 (sem 17·9) μmol/l, P<0·006), which was reached in one-third the time (P<0·009). When HMB-FA and Ca-HMB were administered in water, the differences still favoured HMB-FA, albeit to a lesser degree. Plasma HMB with HMB-FA administered in water was greater during the early phase of absorption (up to 45 min postadministration, P<0·05); this resulted in increased AUC during the first 60 min after administration, when compared with Ca-HMB mixed in water (P<0·03). In conclusion, HMB-FA in capsule form improves clearance rate and availability of HMB compared with Ca-HMB in capsule form.
Journal Article
Free acid gel form of β-hydroxy-β-methylbutyrate (HMB) improves HMB clearance from plasma in human subjects compared with the calcium HMB salt
by
Sharp, Rick L.
,
Angus, Hector F.
,
Baier, Shawn M.
in
Adult
,
Biological and medical sciences
,
Biological Availability
2011
The leucine metabolite, β-hydroxy-β-methylbutyrate (HMB), is a nutritional supplement that increases lean muscle and strength with exercise and in disease states. HMB is presently available as the Ca salt (CaHMB). The present study was designed to examine whether HMB in free acid gel form will improve HMB availability to tissues. Two studies were conducted and in each study four males and four females were given three treatments in a randomised, cross-over design. Treatments were CaHMB (gelatin capsule, 1 g), equivalent HMB free acid gel swallowed (FASW) and free acid gel held sublingual for 15 s then swallowed (FASL). Plasma HMB was measured for 3 h following treatment in study 1 and 24 h with urine collection in study 2. In both the studies, the times to peak plasma HMB were 128 (sem 11), 38 (sem 4) and 38 (sem 1) min (P < 0·0001) for CaHMB, FASW and FASL, respectively. The peak concentrations were 131 (sem 6), 249 (sem 14) and 239 (sem 14) μmol/l (P < 0·0001) for CaHMB, FASW and FASL, respectively. The areas under the curve were almost double for FASW and FASL (P < 0·0001). Daily urinary HMB excretion was not significantly increased resulting in more HMB retained (P < 0·003) with FASW and FASL. Half-lives were 3·17 (sem 0·22), 2·50 (sem 0·13) and 2·51 (sem 0·14) h for CaHMB, FASW and FASL, respectively (P < 0·004). Free acid gel resulted in quicker and greater plasma concentrations (+185 %) and improved clearance (+25 %) of HMB from plasma. In conclusion, HMB free acid gel could improve HMB availability and efficacy to tissues in health and disease.
Journal Article
Comparison of availability and plasma clearance rates of ...-hydroxy-...-methylbutyrate delivery in the free acid and calcium salt forms
by
Khoo, Paul Y
,
Angus, Hector F
,
Fuller, John C
in
Amino acids
,
Bioavailability
,
Dietary supplements
2015
[...]-Hydroxy-[...]-methylbutyrate (HMB), a leucine metabolite, has long been supplemented as a Ca salt (Ca-HMB) to increase strength and performance gains with exercise and to reduce recovery time. Recently, the free acid form of HMB (HMB-FA) has become commercially available in capsule form (gelcap). The current study was conducted to compare the bioavailability of HMB using the two commercially available capsule forms of HMB-FA and Ca-HMB. We also compared the pharmacokinetics of each form when administered mixed in water. Ten human subjects (five male and five female) were studied in a randomised crossover design. There was no significant sex by treatment interaction for any of the pharmacokinetic parameters measured. HMB-FA administered in capsules was more efficient than Ca-HMB capsule at HMB delivery with a 37 % increase in plasma clearance rate (74·8 (sem 4·0) v. 54·5 (sem 3·2) ml/min, P<0·0001) and a 76 % increase in peak plasma HMB concentration (270·2 (sem 17·8) v. 153·9 (sem 17·9)[...]mol/l, P<0·006), which was reached in one-third the time (P<0·009). When HMB-FA and Ca-HMB were administered in water, the differences still favoured HMB-FA, albeit to a lesser degree. Plasma HMB with HMB-FA administered in water was greater during the early phase of absorption (up to 45 min postadministration, P<0·05); this resulted in increased AUC during the first 60 min after administration, when compared with Ca-HMB mixed in water (P<0·03). In conclusion, HMB-FA in capsule form improves clearance rate and availability of HMB compared with Ca-HMB in capsule form.
Journal Article
Comparison of availability and plasma clearance rates of beta -hydroxy- beta -methylb utyrate delivery in the free acid and calcium salt forms
2015
beta -Hydroxy- beta -methylbuty rate (HMB), a leucine metabolite, has long been supplemented as a Ca salt (Ca-HMB) to increase strength and performance gains with exercise and to reduce recovery time. Recently, the free acid form of HMB (HMB-FA) has become commercially available in capsule form (gelcap). The current study was conducted to compare the bioavailability of HMB using the two commercially available capsule forms of HMB-FA and Ca-HMB. We also compared the pharmacokinetics of each form when administered mixed in water. Ten human subjects (five male and five female) were studied in a randomised crossover design. There was no significant sex by treatment interaction for any of the pharmacokinetic parameters measured. HMB-FA administered in capsules was more efficient than Ca-HMB capsule at HMB delivery with a 37 % increase in plasma clearance rate (74.8 (sem 4.0) v. 54.5 (sem 3.2) ml/min, P<0.0001) and a 76 % increase in peak plasma HMB concentration (270.2 (sem 17.8) v. 153.9 (sem 17.9) mu mol/l, P<0.006), which was reached in one-third the time (P<0.009). When HMB-FA and Ca-HMB were administered in water, the differences still favoured HMB-FA, albeit to a lesser degree. Plasma HMB with HMB-FA administered in water was greater during the early phase of absorption (up to 45 min postadministration, P<0.05); this resulted in increased AUC during the first 60 min after administration, when compared with Ca-HMB mixed in water (P<0.03). In conclusion, HMB-FA in capsule form improves clearance rate and availability of HMB compared with Ca-HMB in capsule form.
Journal Article
Free acid gel form of beta-hydroxy-beta-methylbutyrate (HMB) improves HMB clearance from plasma in human subjects compared with the calcium HMB salt
by
Baier, Shawn M
,
Angus, Hector F
,
Fuller, John C
in
Bioavailability
,
Dietary supplements
,
Metabolism
2011
The leucine metabolite, β-hydroxy-β-methylbutyrate (HMB), is a nutritional supplement that increases lean muscle and strength with exercise and in disease states. HMB is presently available as the Ca salt (CaHMB). The present study was designed to examine whether HMB in free acid gel form will improve HMB availability to tissues. Two studies were conducted and in each study four males and four females were given three treatments in a randomised, cross-over design. Treatments were CaHMB (gelatin capsule, 1 g), equivalent HMB free acid gel swallowed (FASW) and free acid gel held sublingual for 15 s then swallowed (FASL). Plasma HMB was measured for 3 h following treatment in study 1 and 24 h with urine collection in study 2. In both the studies, the times to peak plasma HMB were 128 (sem 11), 38 (sem 4) and 38 (sem 1) min (P < 0·0001) for CaHMB, FASW and FASL, respectively. The peak concentrations were 131 (sem 6), 249 (sem 14) and 239 (sem 14) μmol/l (P < 0·0001) for CaHMB, FASW and FASL, respectively. The areas under the curve were almost double for FASW and FASL (P < 0·0001). Daily urinary HMB excretion was not significantly increased resulting in more HMB retained (P < 0·003) with FASW and FASL. Half-lives were 3·17 (sem 0·22), 2·50 (sem 0·13) and 2·51 (sem 0·14) h for CaHMB, FASW and FASL, respectively (P < 0·004). Free acid gel resulted in quicker and greater plasma concentrations (+185 %) and improved clearance (+25 %) of HMB from plasma. In conclusion, HMB free acid gel could improve HMB availability and efficacy to tissues in health and disease. [PUBLICATION ABSTRACT]
Journal Article
Swimming
2000
This chapter contains section titled:
Introduction
Energy demands of swimming training
Body composition
Carbohydrate ingestion during training sessions
Carbohydrate ingestion after training
Protein requirements during swimming training
Micronutrient requirements in competitive swimming
Conclusion
References
Book Chapter
Endovascular ultrasound renal denervation to treat hypertension (RADIANCE-HTN SOLO): a multicentre, international, single-blind, randomised, sham-controlled trial
2018
Early studies suggest that radiofrequency-based renal denervation reduces blood pressure in patients with moderate hypertension. We investigated whether an alternative technology using endovascular ultrasound renal denervation reduces ambulatory blood pressure in patients with hypertension in the absence of antihypertensive medications.
RADIANCE-HTN SOLO was a multicentre, international, single-blind, randomised, sham-controlled trial done at 21 centres in the USA and 18 in Europe. Patients with combined systolic–diastolic hypertension aged 18–75 years were eligible if they had ambulatory blood pressure greater than or equal to 135/85 mm Hg and less than 170/105 mm Hg after a 4-week discontinuation of up to two antihypertensive medications and had suitable renal artery anatomy. Patients were randomised (1:1) to undergo renal denervation with the Paradise system (ReCor Medical, Palo Alto, CA, USA) or a sham procedure consisting of renal angiography only. The randomisation sequence was computer generated and stratified by centres with randomised blocks of four or six and permutation of treatments within each block. Patients and outcome assessors were blinded to randomisation. The primary effectiveness endpoint was the change in daytime ambulatory systolic blood pressure at 2 months in the intention-to-treat population. Patients were to remain off antihypertensive medications throughout the 2 months of follow-up unless specified blood pressure criteria were exceeded. Major adverse events included all-cause mortality, renal failure, an embolic event with end-organ damage, renal artery or other major vascular complications requiring intervention, or admission to hospital for hypertensive crisis within 30 days and new renal artery stenosis within 6 months. This study is registered with ClinicalTrials.gov, number NCT02649426.
Between March 28, 2016, and Dec 28, 2017, 803 patients were screened for eligibility and 146 were randomised to undergo renal denervation (n=74) or a sham procedure (n=72). The reduction in daytime ambulatory systolic blood pressure was greater with renal denervation (−8·5 mm Hg, SD 9·3) than with the sham procedure (−2·2 mm Hg, SD 10·0; baseline-adjusted difference between groups: −6·3 mm Hg, 95% CI −9·4 to −3·1, p=0·0001). No major adverse events were reported in either group.
Compared with a sham procedure, endovascular ultrasound renal denervation reduced ambulatory blood pressure at 2 months in patients with combined systolic–diastolic hypertension in the absence of medications.
ReCor Medical.
Journal Article