Biomedical subjects

Alejandro Lucia

Publications and source records attributed to Alejandro Lucia.

23 records · Page 2Linked to original sources

PubMed2004

Effects of oral ATP supplementation on anaerobic power and muscular strength.

PURPOSE: We examined 14 d of oral adenosine 5'-triphosphate (ATP) supplementation on indices of anaerobic capacity and muscular strength. METHODS: Twenty-seven healthy males successfully completed the trial, after randomly receiving in a double-blind manner an oral dose of low dose (150 mg) or high dose (225 mg) ATP, or matched placebo. To improve absorption characteristics, the ATP was enterically coated. Total blood ATP (whole blood and plasma ATP) concentrations, two Wingate anaerobic power tests (30 s), and muscular strength (1RM and three sets of repetitions to fatigue at 70% of 1RM) were measured under three conditions: (i) baseline; (ii) acutely (7d later, no prior supplementation and 75 min after ATP ingestion); and (iii) after 14 d of daily ingestion (post). RESULTS: Statistical analyses showed no significant between or within group treatment effects for whole blood ATP or plasma ATP concentrations for any treatment condition. We also did not observe any treatment effects for any Wingate testing parameter including peak PO, total work, average PO for 30 s, or post-Wingate lactate accumulation. Overall, we observed no significant between group treatment effects for any muscular strength parameter. We did observe several within group differences for the group ingesting the high ATP dosage including 1RM (6.6%; P < 0.04) and repetitions to fatigue during set 1 of posttesting (18.5%; P < 0.007) and total lifting volume at post (22%; P < 0.003). CONCLUSIONS: We conclude that enterically coated oral ATP supplementation may provide small ergogenic effects on muscular strength under some treatment conditions.

Adenosine Triphosphate↗

PubMed2004

In professional road cyclists, low pedaling cadences are less efficient.

PURPOSE: To determine the effects of changes in pedaling frequency on the gross efficiency (GE) and other physiological variables (oxygen uptake (VO2), HR, lactate, pH, ventilation, motor unit recruitment estimated by EMG) of professional cyclists while generating high power outputs (PO). METHODS: Following a counterbalanced, cross-over design, eight professional cyclists (age (mean +/- SD): 26 +/- 2 yr, VO2max: 74.0 +/- 5.7 mL x kg x min) performed three 6-min bouts at a fixed PO (mean of 366 +/- 37 W) and at a cadence of 60, 80, and 100 rpm. RESULTS: Values of GE averaged 22.4 +/- 1.7, 23.6 +/- 1.8 and 24.2 +/- 2.0% at 60, 80, and 100 rpm, respectively. Mean GE at 100 rpm was significantly higher than at 60 rpm (P < 0.05). Similarly, mean values of VO2, HR, rates of perceived exertion (RPE), lactate and normalized root-mean square EMG (rms-EMG) in both vastus lateralis and gluteus maximum muscles decreased at increasing cadences. CONCLUSIONS: In professional road cyclists riding at high PO, GE/economy improves at increasing pedaling cadences.

Adult↗

PubMed2004

Low vs. high glycemic index carbohydrate gel ingestion during simulated 64-km cycling time trial performance.

We examined the effect of low and high glycemic index (GI) carbohydrate (CHO) feedings during a simulated 64-km cycling time trial (TT) in nine subjects ([mean +/- SEM], age = 30 +/- 1 years; weight = 77.0 +/- 2.6 kg). Each rider completed three randomized, double blind, counter-balanced, crossover rides, where riders ingested 15 g of low GI (honey; GI = 35) and high GI (dextrose; GI = 100) CHO every 16 km. Our results showed no differences between groups for the time to complete the entire TT (honey = 128 minutes, 42 seconds +/- 3.6 minutes; dextrose = 128 minutes, 18 seconds +/- 3.8 minutes; placebo = 131 minutes, 18 seconds +/- 3.9 minutes). However, an analysis of total time alone may not portray an accurate picture of TT performance under CHO-supplemented conditions. For example, when the CHO data were collapsed, the CHO condition (128 minutes, 30 seconds) proved faster than placebo condition (131 minutes, 18 seconds; p < 0.02). Furthermore, examining the percent differences and 95% confidence intervals (CI) shows the two CHO conditions to be generally faster, as the majority of the CI lies in the positive range: placebo vs. dextrose (2.36% [95% CI; -0.69, 4.64]) and honey (1.98% [95% CI; -0.30, 5.02]). Dextrose vs. honey was 0.39% (95% CI; -3.39, 4.15). Within treatment analysis also showed that subjects generated more watts (W) over the last 16 km vs. preceding segments for dextrose (p < 0.002) and honey (p < 0.0004) treatments. When the final 16-km W was expressed as a percentage of pretest maximal W, the dextrose treatment was greater than placebo (p < 0.05). A strong trend was noted for the honey condition (p < 0.06), despite no differences in heart rate (HR) or rate of perceived exertion (RPE). Our results show a trend for improvement in time and wattage over the last 16 km of a 64-km simulated TT regardless of glycemic index.

Adult↗

PubMed2003

The Tour de France: a physiological review.

On 5 July 2003, the Tour de France (TDF) has celebrated 100th running. Instead of a chimney sweep competing during his free time (as in 1903), the recent winner is a highly trained, professional cyclist whose entire life-style has been dedicated to reach his pinnacle during this event. The TDF has been held successfully for 100 years, but the application of the physiologic sciences to the sport is a relatively recent phenomenon. Although some historical reports help to understand the unique physiological characteristics of this race, scientific studies were not available in Sports Science/Applied Physiology journals until the 1990s. The aim of this article is to review the history of the TDF. Special emphasis is placed on the last decade where classic physiology has been integrated into applied scientific cycling data.

Bicycling↗

PubMed2003

Tour de France versus Vuelta a España: which is harder?

PURPOSE: To compare the total exercise loads (intensity x volume) of the Vuelta a España and Tour de France during the last year. METHODS: Seven professional road cyclists (28 +/- 1 yr; [OV0312]O(2max): 74.6 +/- 2.2 mL.kg-1.min-1) who participated in both Tour and Vuelta during the years 1997, 1999, 2000, or 2001 were collected as subjects. They wore a heart rate (HR) telemeter during each stage of the two races, and exercise intensity was divided into three phases according to the reference HR values obtained during a previous ramp cycle-ergometer test: phase I ( RCP). Total volume and intensity were integrated as a single variable. The score for volume x intensity in each phase was computed by multiplying the accumulated duration in this phase by a multiplier for this particular phase. The total score for Tour and Vuelta was obtained by summating the results of the three phases. RESULTS: The total loads (volume x intensity) did not significantly differ between the two races (P > 0.05), despite a significantly longer total exercise time of the Tour (P < 0.05) (5552 +/- 176 vs 5086 +/- 290 min). CONCLUSION: The physiological loads imposed on cyclists' bodies do not differ between the Tour and Vuelta, despite the longer duration of daily stages in the former race.

Adult↗