Effective Nutritional Ergogenic Aids

1999 ◽  
Vol 9 (2) ◽  
pp. 229-239 ◽  
Author(s):  
Elizabeth Applegate

Athletes use a variety of nutritional ergogenic aids to enhance performance. Most nutritional aids can be categorized as a potential energy source, an anabolic enhancer, a cellular component, or a recovery aid. Studies have consistently shown that carbohydrates consumed immediately before or after exercise enhance performance by increasing glycogen stores and delaying fatigue. Protein and amino acid supplementation may serve an anabolic role by optimizing body composition crucial in strength-related sports. Dietary antioxidants, such as vitamins C and E and carotenes, may prevent oxidative stress that occurs with intense exercise. Performance during high-intensity exercise, such as sprinting, may be improved with short-term creatine loading, and high-effort exercise lasting 1-7 min may be improved through bicarbonate loading immediately prior to activity. Caffeine dosing before exercise delays fatigue and may enhance performance of high-intensity exercise.

1998 ◽  
Vol 85 (4) ◽  
pp. 1502-1508 ◽  
Author(s):  
F. Greer ◽  
C. McLean ◽  
T. E. Graham

Investigations examining the ergogenic and metabolic influence of caffeine during short-term high-intensity exercise are few in number and have produced inconsistent results. This study examined the effects of caffeine on repeated bouts of high-intensity exercise in recreationally active men. Subjects ( n = 9) completed four 30-s Wingate (WG) sprints with 4 min of rest between each exercise bout on two separate occasions. One hour before exercise, either placebo (Pl; dextrose) or caffeine (Caf; 6 mg/kg) capsules were ingested. Caf ingestion did not have any effect on power output (peak or average) in the first two WG tests and had a negative effect in the latter two exercise bouts. Plasma epinephrine concentration was significantly increased 60 min after Caf ingestion compared with Pl; however, this treatment effect disappeared once exercise began. Caf ingestion had no significant effect on blood lactate, O2 consumption, or aerobic contribution at any time during the protocol. After the second Wingate test, plasma NH3concentration increased significantly from the previous WG test and was significantly higher in the Caf trial compared with Pl. These data demonstrate no ergogenic effect of caffeine on power output during repeated bouts of short-term, intense exercise. Furthermore, there was no indication of increased anaerobic metabolism after Caf ingestion with the exception of an increase in NH3 concentration.


2010 ◽  
Vol 108 (6) ◽  
pp. 1472-1478 ◽  
Author(s):  
Patrice Brassard ◽  
Thomas Seifert ◽  
Mads Wissenberg ◽  
Peter M. Jensen ◽  
Christian K. Hansen ◽  
...  

Whether sympathetic activity influences cerebral blood flow (CBF) and oxygenation remains controversial. The influence of sympathetic activity on CBF and oxygenation was evaluated by the effect of phenylephrine on middle cerebral artery (MCA) mean flow velocity ( Vmean) and the near-infrared spectroscopy-derived frontal lobe oxygenation (ScO2) at rest and during exercise. At rest, nine healthy male subjects received bolus injections of phenylephrine (0.1, 0.25, and 0.4 mg), and changes in mean arterial pressure (MAP), MCA Vmean, internal jugular venous O2 saturation (SjvO2), ScO2, and arterial Pco2 (PaCO2) were measured and the cerebral metabolic rate for O2 (CMRO2) was calculated. In randomized order, a bolus of saline or 0.3 mg of phenylephrine was then injected during semisupine cycling, eliciting a low (∼110 beats/min) or a high (∼150 beats/min) heart rate. At rest, MAP and MCA Vmean increased ∼20% ( P < 0.001) and ∼10% ( P < 0.001 for 0.25 mg of phenylephrine and P < 0.05 for 0.4 mg of phenylephrine), respectively. ScO2 then decreased ∼7% ( P < 0.001). Phenylephrine had no effect on SjvO2, PaCO2, or CMRO2. MAP increased after the administration of phenylephrine during low-intensity exercise (∼15%), but this was attenuated (∼10%) during high-intensity exercise ( P < 0.001). The reduction in ScO2 after administration of phenylephrine was attenuated during low-intensity exercise (−5%, P < 0.001) and abolished during high-intensity exercise (−3%, P = not significant), where PaCO2 decreased 7% ( P < 0.05) and CMRO2 increased 17% ( P < 0.05). These results suggest that the administration of phenylephrine reduced ScO2 but that the increased cerebral metabolism needed for moderately intense exercise eliminated that effect.


2003 ◽  
Vol 94 (6) ◽  
pp. 2135-2144 ◽  
Author(s):  
Murli Manohar ◽  
Thomas E. Goetz ◽  
Aslam S. Hassan

It is reported that preexercise hyperhydration caused arterial O2 tension of horses performing submaximal exercise to decrease further by 15 Torr (Sosa-Leon L, Hodgson DR, Evans DL, Ray SP, Carlson GP, and Rose RJ. Equine Vet J Suppl 34: 425–429, 2002). Because hydration status is important to optimal athletic performance and thermoregulation during exercise, the present study examined whether preexercise induction of hypervolemia would similarly accentuate the arterial hypoxemia in Thoroughbreds performing short-term high-intensity exercise. Two sets of experiments (namely, control and hypervolemia studies) were carried out on seven healthy, exercise-trained Thoroughbred horses in random order, 7 days apart. In resting horses, an 18.0 ± 1.8% increase in plasma volume was induced with NaCl (0.30–0.45 g/kg dissolved in 1,500 ml H2O) administered via a nasogastric tube, 285–290 min preexercise. Blood-gas and pH measurements as well as concentrations of plasma protein, hemoglobin, and blood lactate were determined at rest and during incremental exercise leading to maximal exertion (14 m/s on a 3.5% uphill grade) that induced pulmonary hemorrhage in all horses in both treatments. In both treatments, significant arterial hypoxemia, desaturation of hemoglobin, hypercapnia, acidosis, and hyperthermia developed during maximal exercise, but statistically significant differences between treatments were not found. Thus preexercise 18% expansion of plasma volume failed to significantly affect the development and/or severity of arterial hypoxemia in Thoroughbreds performing maximal exercise. Although blood lactate concentration and arterial pH were unaffected, hemodilution caused in this manner resulted in a significant ( P < 0.01) attenuation of the exercise-induced expansion of the arterial-to-mixed venous blood O2 content gradient.


2013 ◽  
Vol 110 (12) ◽  
pp. 1232-1240 ◽  
Author(s):  
Francesca Santilli ◽  
Natale Vazzana ◽  
Pierpaolo Iodice ◽  
Stefano Lattanzio ◽  
Rossella Liani ◽  
...  

SummaryPhysical activity is associated with cardiovascular risk reduction, but the effects of exercise on platelet activation remain controversial. We investigated the effects of regular high-amount, high intensity aerobic exercise on in vivo thromboxane (TX)-dependent platelet activation and plasma levels of platelet-derived proteins, CD40L and P-selectin, and whether platelet variables changes may be related to changes in high-density lipoprotein (HDL) and in the extent of oxidative stress and oxidative stress-related inflammation, as reflected by urinary isoprostane excretion and endogenous soluble receptor for advanced glycation end-products (esRAGE), respectively. Urinary excretion of 11-dehydro-TXB2 and 8-iso-prostaglandin (PG)F2α and plasma levels of P-selectin, CD40L and esRAGE were measured before and after a eight-week standardised aerobic high-amount–high-intensity training program in 22 sedentary subjects with low-to-intermediate risk. Exercise training had a clear beneficial effect on HDL cholesterol (+10%, p=0.027) and triglyceride (-27%, p=0.008) concentration. In addition, a significant (p<0.0001) decrease in urinary 11-dehydro-TXB2 (26%), 8-iso-PGF2α (21 %), plasma P-selectin (27%), CD40L (35%) and a 61% increase in esRAGE were observed. Multiple regression analysis revealed that urinary 8-iso-PGF2α [beta=0.33, SEM=0.116, p=0.027] and esRAGE (beta=-0.30, SEM=31.3, p=0.046) were the only significant predictors of urinary 11-dehydro-TXB2 excretion rate over the training period. In conclusion, regular high-amount–high-intensity exercise training has broad beneficial effects on platelet activation markers, paralleled and possibly associated with changes in the lipoprotein profile and in markers of lipid peroxidation and AGE/RAGE axis. Our findings may help explaining why a similar amount of exercise exerts significant benefits in preventing cardiovascular events.


2015 ◽  
Vol 36 (12) ◽  
pp. 984-991 ◽  
Author(s):  
D. Camiletti-Moirón ◽  
V. Aparicio ◽  
E. Nebot ◽  
G. Medina ◽  
R. Martínez ◽  
...  

2011 ◽  
Vol 26 (2) ◽  
pp. 287-290 ◽  
Author(s):  
Sayaka DOMEN ◽  
Shunsuke TAITO ◽  
Kana KONISHI ◽  
Makoto TAKAHASHI ◽  
Kiyokazu SEKIKAWA ◽  
...  

2019 ◽  
Vol 44 (12) ◽  
pp. 1391-1394
Author(s):  
Martin J. MacInnis ◽  
Lauren E. Skelly ◽  
F. Elizabeth Godkin ◽  
Brian J. Martin ◽  
Thomas R. Tripp ◽  
...  

The legs of 9 men (age 21 ± 2 years, 45 ± 4 mL/(kg·min)) were randomly assigned to complete 6 sessions of high-intensity exercise training, involving either one or four 5-min bouts of counterweighted, single-leg cycling. Needle biopsies from vastus lateralis revealed that citrate synthase maximal activity increased after training in the 4-bout group (p = 0.035) but not the 1-bout group (p = 0.10), with a significant difference between groups post-training (13%, p = 0.021). Novelty Short-term training using brief intense exercise requires multiple bouts per session to increase mitochondrial content in human skeletal muscle.


2015 ◽  
Vol 30 (6) ◽  
pp. 1719-1727 ◽  
Author(s):  
Andreia Aparecida de Oliveira Silva ◽  
Ernesto Cesar Pinto Leal-Junior ◽  
Katia de Angelis Lobo D’Avila ◽  
Andrey Jorge Serra ◽  
Regiane Albertini ◽  
...  

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