Search Results

You are looking at 121 - 130 of 559 items for :

  • "anaerobic" x
Clear All
Restricted access

Justine J. Reel, Sonya SooHoo, Holly Doetsch, Jennifer E. Carter and Trent A. Petrie

The purpose of the study was to determine prevalence rates of the female athlete triad (Triad), differences by sport category (aesthetic, endurance, and team/anaerobic), and the relationship between each of the components of the Triad. Female athletes (N= 451) from three Division I universities with an average age of 20 years completed the Menstrual History Questionnaire, Injury Assessment Questionnaire, and the Questionnaire for Eating Disorder Diagnoses (Q-EDD; Mintz, O’Halloran, Mulholland, & Schneider, 1997). Almost 7% of female athletes reported clinical eating disorders, and 19.2% reported subclinical disordered eating. Disordered eating was prevalent in all three sport categories with no significant differences between groups. Muscle injuries were more prevalent in team/anaerobic sports (77.4%) than the aesthetic (68.1%) and endurance groups (58.1%). Furthermore, those athletes with menstrual dysfunction more frequently reported clinical eating disorders (1.4%) and sustained more skeletal injuries (51%) during their athletic career than athletes with regular menstrual function. Clinical implications and further research directions are addressed.

Restricted access

Christine L. Wells and Steven P. Hooker

Physiological variables identified as important factors in athletic performance are discussed in relation to the spinal cord injured (SCI) athlete. These include body composition, pulmonary function, cardiorespiratory efficiency, muscular strength and endurance, and anaerobic power. SCI athletes are less fat and have a larger lean body mass than nonathletes, and male SCI are less fat than female SCI. Static lung volumes are usually below normal values in SCI subjects, but athletic SCI subjects tend to have higher values than sedentary SCI. Sedentary SCI subjects have lower aerobic power (O2max) than the general able-bodied (AB) sedentary population on tests of arm cranking or wheelchair ergometry. Low-lesion paraplegics generally achieve O2max values comparable to AB subjects. O2max is inversely related to level of injury, that is, the higher the SCI, the lower the O2max. However, elite SCI athletes are capable of achieving very high levels of O2max during arm exercise. SCI subjects respond well to strength and muscular endurance training. Paraplegic subjects achieve higher anaerobic power scores than quadriplegic subjects. Increases in O2max occur at about the same magnitude as in AB subjects. The required intensity level appears to be about 70–80% of maximal heart rate reserve.

Restricted access

Josely C. Koury, Astrogildo V. de Oliveira Jr., Emílson S. Portella, Cyntia F. de Oliveira, Gustavo C. Lopes and Carmen M. Donangelo

The purpose of this study was lo compare zinc and copper biochemical indices of antioxidant status and their relationship in elite athletes of different modalities: aerobic with high-impact (triathletes, n = 10 and long-distance runners, n = 12), anaerobic with high-impact (short-distance runners, n = 9), and anaerobic with low-impact (short-distance swimmers, n = 13). The influence of recent dietary intake and body composition was also evaluated. A venous blood sample was drawn 16-20 hr after competition for the following measurements: packed-cell volume and hemoglobin in blood; copper and zinc in plasma and erythrocytes; ceruloplasmin in plasma; superoxide dismutase activity and metal-lothionein in erythrocyles; and erythrocyte osmotic fragility. Zinc and copper intakes were not different in the athlete groups and did not affect the biochemical indices measured. Athletes of the long-distance high-impact aerobic modalities had higher indices of antioxidant protection (erythrocyte zinc, superoxide dismutase activity, and metallothionein) than those of the short-distance low-impact modalities, suggesting that there is adaptation of the antioxidant capacity to the specific training. Significant correlations were observed in all athletes between erythrocyte zinc, superoxide dismutase activity, and metallothionein consistent with the importance of an adequate zinc status in the response of antioxidant mechanisms to intense exercise.

Restricted access

Rachel A. Hildebrand, Bridget Miller, Aric Warren, Deana Hildebrand and Brenda J. Smith

Increasing evidence indicates that compromised vitamin D status, as indicated by serum 25-hydroxyvitamin D (25-OH D), is associated with decreased muscle function. The purpose of this study was to determine the vitamin D status of collegiate athletes residing in the southern U.S. and its effects on muscular strength and anaerobic power. Collegiate athletes (n = 103) from three separate NCAA athletic programs were recruited for the study. Anthropometrics, vitamin D and calcium intake, and sun exposure data were collected along with serum 25-OH D and physical performance measures (Vertical Jump Test, Shuttle Run Test, Triple Hop for Distance Test and the 1 Repetition Maximum Squat Test) to determine the influence of vitamin D status on muscular strength and anaerobic power. Approximately 68% of the study participants were vitamin D adequate (>75 nmol/L), whereas 23% were insufficient (75–50 nmol/L) and 9%, predominantly non-Caucasian athletes, were deficient (<50 nmol/L). Athletes who had lower vitamin D status had reduced performance scores (p < .01) with odds ratios of 0.85 on the Vertical Jump Test, 0.82 on the Shuttle Run Test, 0.28 on the Triple Hop for Distance Test, and 0.23 on the 1 RM Squat Test. These findings demonstrate that even NCAA athletes living in the southern US are at risk for vitamin D insufficiency and deficiency and that maintaining adequate vitamin D status may be important for these athletes to optimize their muscular strength and power.

Restricted access

Philip Davis, Renate M. Leithäuser and Ralph Beneke

The energy expenditure of amateur boxing is unknown.

Purpose:

Total metabolic cost (Wtot) as an aggregate of aerobic (Waer), anaerobic lactic (W[lactate]), and anaerobic alactic (WPCr) energy of a 3 × 2-min semicontact amateur boxing bout was analyzed.

Methods:

Ten boxers (mean ± SD [lower/upper 95% confidence intervals]) age 23.7 ± 4.1 (20.8/26.6) y, height 180.2 ± 7.0 (175.2/185.2) cm, body mass 70.6 ± 5.7 (66.5/74.7) kg performed a semicontact bout against handheld pads created from previously analyzed video footage of competitive bouts. Net metabolic energy was calculated using respiratory gases and blood [lactate].

Results:

Waer, 526.0 ± 57.1 (485.1/566.9) kJ, was higher (P < .001) than WPCr, 58.1 ± 13.6 (48.4/67.8) kJ. W[lactate], 26.2 ± 7.1 (21.1/31.3) kJ, was lower (P < .001) than Waer and WPCr. An ~70-kJ fraction of the aerobic energy expenditure reflects rephosphorylation of high-energy phosphates during the breaks between rounds, which elevated Wtot to ~680 kJ with relative contributions of 77% Waer, 19% WPCr, and 4% W[lactate].

Conclusions:

The results indicate that the metabolic profile of amateur boxing is predominantly aerobic. They also highlight the importance of a highly developed aerobic capacity as a prerequisite of a high activity rate during rounds and recovery of the high-energy phosphate system during breaks as interrelated requirements of successful boxing.

Restricted access

Edward J. Smith, Ryan Storey and Mayur K. Ranchordas

Bouldering competitions are held up to International level and governed by the International Federation of Sport Climbing. Bouldering has been selected to feature at the 2020 Olympic Games in Tokyo, however, physiological qualities and nutritional requirements to optimize performance remain inadequately defined due to large gaps in the literature. The primary goals of training include optimizing the capacity of the anaerobic energy systems and developing sport-specific strength, with emphasis on the isometric function of the forearm flexors responsible for grip. Bouldering athletes typically possess a lean physique, similar to the characteristics of sport climbers with reported body fat values of 6–12%. Athletes strive for a low body weight to improve power to weight ratio and limit the load on the extremities. Specialized nutritional support is uncommon and poor nutritional practices such as chronic carbohydrate restriction are prevalent, compromising the health of the athletes. The high intensity nature of bouldering demands a focus on adequate carbohydrate availability. Protein intake and timing should be structured to maximize muscle protein synthesis and recovery, with the literature suggesting 0.25–0.3 g/kg in 3–4 hr intervals. Supplementing with creatine and b-alanine may provide some benefit by augmenting the capacity of the anaerobic systems. Boulderers are encouraged to seek advice from nutrition experts to enhance performance, particularly important when weight loss is the desired outcome. Further research is warranted across all nutritional aspects of bouldering which is summarized in this review.

Restricted access

Alessandro Moura Zagatto, Jorge Vieira de Mello Leite, Marcelo Papoti and Ralph Beneke

Purpose:

To test the hypotheses that the metabolic profile of table tennis is dominantly aerobic, anaerobic energy is related to the accumulated duration and intensity of rallies, and activity and metabolic profile are interrelated with the individual fitness profile determined via table tennis–specific tests.

Methods:

Eleven male experienced table tennis players (22 ± 3 y, 77.6 ± 18.9 kg, 177.1 ± 8.1 cm) underwent 2 simulated table tennis matches to analyze aerobic (WOXID) energy, anaerobic glycolytic (WBLC) energy, and phosphocreatine breakdown (WPCr); a table tennis–specific graded exercise test to measure ventilatory threshold and peak oxygen uptake; and an exhaustive supramaximal table tennis effort to determine maximal accumulated deficit of oxygen.

Results:

WOXID, WBLC, and WPCr corresponded to 96.5% ± 1.7%, 1.0% ± 0.7%, and 2.5% ± 1.4%, respectively. WOXID was interrelated with rally duration (r = .81) and number of shots per rally (r = .77), whereas match intensity was correlated with WPCr (r = .62) and maximal accumulated oxygen deficit (r = .58).

Conclusions:

The metabolic profile of table tennis is predominantly aerobic and interrelated with the individual fitness profile determined via table tennis–specific tests. Table tennis–specific ventilatory threshold determines the average oxygen uptake and overall WOXID, whereas table tennis–specific maximal accumulated oxygen deficit indicates the ability to use and sustain slightly higher blood lactate concentration and WBLC during the match.

Restricted access

Claire Rechichi, Brian Dawson and Carmel Goodman

Some reports suggest variation in physiological responses and athletic performance, for female athletes at specific phases of the menstrual cycle. However, inconsistent findings are common due to the inappropriate verification of menstrual cycle phase, small subject numbers, high intra- and interindividual variability in estrogen and progesterone concentration, and the pulsatile secretion of these hormones. Therefore, the oral contraceptive (OC) cycle may provide a more stable environment in which to evaluate the acute effect of reproductive hormones on physiological variables and exercise performance. To date, most of the OC research has compared differences between OC use and nonuse, and few researchers have examined within-cycle effects of the OC. It is also apparent that OC use is becoming far more prevalent in athletes; hence the effect of the different exogenous and endogenous hormonal profiles on athletic performance should be investigated. Research to date identifies potential for variation in aerobic performance, anaerobic capacity, anaerobic power and reactive strength throughout an OC cycle. The purpose of this review is to present and evaluate the current literature on the physiology of exercise and athletic performance during the OC cycle.

Restricted access

Michelle S.M. Silva, Wladimir Bolani, Cleber R. Alves, Diogo G. Biagi, José R. Lemos Jr, Jeferson L. da Silva, Patrícia A. de Oliveira, Guilherme B. Alves, Edilamar M. de Oliveira, Carlos E. Negrão, José E. Krieger, Rodrigo G. Dias and Alexandre C. Pereira

Aim:

To study the relationship between the ACTN3 R577X polymorphism and oxygen uptake (VO2) before and after exercise training.

Methods:

Police recruits (N = 206, 25 ± 4 y) with RR (n = 75), RX (n = 97), and XX (n = 33) genotypes were selected. After baseline measures, they underwent 18 wk of running endurance training. Peak VO2 was obtained by cardiopulmonary exercise testing.

Results:

Baseline body weight was not different among genotypes. At baseline, XX individuals displayed higher VO2 at anaerobic threshold, respiratory compensation point, and exercise peak than did RR individuals (P < .003). Endurance training significantly increased VO2 at anaerobic threshold, respiratory compensation point, and exercise peak (P < 2 × 10−6), but the differences between XX and RR were no longer observed. Only relative peak VO2 exercise remained higher in XX than in RR genotype (P = .04). In contrast, the increase in relative peak VO2 was greater in RR than in XX individuals (12% vs 6%; P = .02).

Conclusion:

ACTN3 R577X polymorphism is associated with VO2. XX individuals have greater aerobic capacity. Endurance training eliminates differences in peak VO2 between XX and RR individuals. These findings suggest a ceiling-effect phenomenon, and, perhaps, trained individuals may not constitute an adequate population to explain associations between phenotypic variability and gene variations.

Restricted access

Mark A. Tarnopolsky and Dan P. MacLennan

Creatine monohydrate supplementation has been shown to enhance high-intensity exercise performance in some but not all studies. Part of the controversy surrounding the ergogenic effect(s) of creatine monohydrate supplementation may relate to design issues that result in low statistical power. A further question that remains unresolved in the creatine literature is whether or not males and females respond in a similar manner to supplementation. We studied the effect of creatine supplementation upon high intensity exercise performance in 24 subjects (n = 12 males, n = 12 females). Creatine monohydrate (Cr; 5g, 4x/d × 4d) and placebo (PI; glucose polymer × 4d) were provided using a randomized. double-blind crossover design (7 week washout). Outcome measures included: 2 × 30-S anaerobic cycle lest, with plasma lactate pre- and post-test; dorsi-flexor: maximal voluntary contraction (MVC), 2-min fatigue test, and electrically stimulated peak and tetanic torque; isokinetic knee extension torque and I -min ischeniic handgrip strength. Significant main effects of Cr treatment included: increased peak and relative peak anaerobic cycling power (↑3.7%; p < .05), dorsi-flexion MVC torque (↑6.6% p < .05), and increased lactate (↑20.8%; p < .05) with no gender specific responses. We concluded that short-term Cr supplementation can increase indices of high-intensity exercise performance for both males and females.