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1.
This study aimed to describe the body composition and physiological changes which take place during the in-season and recovery periods of a group of natural bodybuilders. Natural male bodybuilders (n?=?9) were assessed 16 (PRE16), 8 (PRE8), and 1 (PRE1) week(s) before, and 4 (POST4) weeks after a bodybuilding competition. Assessments included body composition, resting metabolic rate (RMR), serum hormones, and 7-day weighed food and training diaries. Change in parameters was assessed using repeated-measures analysis of variance. Dietary protein intake remained high throughout the study period (2.8–3.1?g?kg?1?d?1). Fat mass (FM) was significantly reduced from PRE16 to PRE1 (8.8?±?3.1 vs. 5.3?±?2.4?kg, P?.01). There was a small decrease in lean mass (LM) from PRE8 to PRE1 (71.8?±?9.1 vs. 70.9?±?9.1?kg, P?P?>?.05). Large reductions in total and free testosterone (16.4?±?4.4 vs. 10.1?±?3.6?nmol?L?1, P?. 116.8?±?76.9?pmol?L?1, P?. 19.9?±?7.6?nmol?L?1, P?. 72.5?±?8.5?kg, P?. 25.4?±?9.3?nmol?L?1, P?相似文献   

2.
Abstract

The current study implemented a two-part design to (1) assess the vitamin D concentration of a large cohort of non-vitamin D supplemented UK-based athletes and 30 age-matched healthy non-athletes and (2) to examine the effects of 5000 IU · day?1 vitamin D3 supplementation for 8-weeks on musculoskeletal performance in a placebo controlled trial. Vitamin D concentration was determined as severely deficient if serum 25(OH)D < 12.5 nmol · l?1, deficient 12.5–30 nmol · l?1 and inadequate 30–50 nmol · l?1. We demonstrate that 62% of the athletes (38/61) and 73% of the controls (22/30) exhibited serum total 25(OH)D < 50 nmol · l?1. Additionally, vitamin D supplementation increased serum total 25(OH)D from baseline (mean ± SD = 29 ± 25 to 103 ± 25 nmol · l?1, P = 0.0028), whereas the placebo showed no significant change (53 ± 29 to 74 ± 24 nmol · l?1, P = 0.12). There was a significant increase in 10 m sprint times (P = 0.008) and vertical-jump (P = 0.008) in the vitamin D group whereas the placebo showed no change (P = 0.587 and P = 0.204 respectively). The current data supports previous findings that athletes living at Northerly latitudes (UK = 53° N) exhibit inadequate vitamin D concentrations (<50 nmol · l?1). Additionally the data suggests that inadequate vitamin D concentration is detrimental to musculoskeletal performance in athletes. Future studies using larger athletic groups are now warranted.  相似文献   

3.
Abstract

Road cycling ranks among the most intense endurance exercises. Previous studies and mathematical models describing road cycling have not analysed performances per se. We describe the evolution of road cycling performance over the past 116 years. We studied the top ten cyclists' mean speeds in eight famous classic races and three European Grand Tours, using a previously published multi-exponential model that highlights the different progression periods of an event during the century. In addition, we measured an indicator of difficulty for the Tour de France by calculating the climbing index (i.e. the total altitude climbed over total distance). The eleven races' mean speed increased progressively from 23.13 km · h?1 in 1892 to 41.19 ± 2.03 km · h?1 in 2008. Road cycling development, like other quantifiable disciplines, fits a piecewise progression pattern that follows three periods: before, between, and after the two World Wars. However, a fourth period begins after 1993, providing a speed progression of 6.38% from the third one. The Tour de France's climbing index also provided insight into a recent paradoxical relationship with speeds: when the climbing index increased, the winner's speed also increased. Our results show a major improvement (6.38%) in road cycling performance in the last 20 years and question the role of extra-physiological parameters in this recent progression.  相似文献   

4.
Abstract

In this study, we investigated the effect of ingesting carbohydrate alone or carbohydrate with protein on functional and metabolic markers of recovery from a rugby union-specific shuttle running protocol. On three occasions, at least one week apart in a counterbalanced order, nine experienced male rugby union forwards ingested placebo, carbohydrate (1.2 g · kg body mass?1 · h?1) or carbohydrate with protein (0.4 g · kg body mass?1 · h?1) before, during, and after a rugby union-specific protocol. Markers of muscle damage (creatine kinase: before, 258 ± 171 U · L?1 vs. 24 h after, 574 ± 285 U · L?1; myoglobin: pre, 50 ± 18 vs. immediately after, 210 ± 84 nmol · L?1; P < 0.05) and muscle soreness (1, 2, and 3 [maximum soreness = 8] for before, immediately after, and 24 h after exercise, respectively) increased. Leg strength and repeated 6-s cycle sprint mean power were slightly reduced after exercise (93% and 95% of pre-exercise values, respectively; P < 0.05), but were almost fully recovered after 24 h (97% and 99% of pre-exercise values, respectively). There were no differences between trials for any measure. These results indicate that in experienced rugby players, the small degree of muscle damage and reduction in function induced by the exercise protocol were not attenuated by the ingestion of carbohydrate and protein.  相似文献   

5.
Abstract

The goal of this study was to investigate the effects of different durations of skin temperature manipulation on pacing patterns and performance during a 15-km cycling time trial. Nineteen well-trained men completed three 15-km cycling time trials in 18°C and 50% relative humidity with 4.5-km (short-heat), 9.0-km (long-heat) or without (control) radiant heat exposure applied by infrared heaters after 1.5 km in the time trial. During the time trials, power output, mean skin temperature, rectal temperature, heart rate and rating of perceived exertion were assessed. The radiant heat exposure resulted in higher mean skin temperature during the time trial for short-heat (35.0 ± 0.6°C) and long-heat (35.3 ± 0.5°C) than for control (32.5 ± 1.0°C; P < 0.001), whereas rectal temperature was similar (P = 0.55). The mean power output was less for short-heat (273 ± 8 W; P = 0.001) and long-heat (271 ± 9 W; P = 0.02) than for control (287 ± 7 W), but pacing patterns did not differ (P = 0.55). Heart rate was greatest in control (177 ± 9 beats · min?1; P < 0.001), whereas the rating of perceived exertion remained similar. We concluded that a radiant heat exposure and associated higher skin temperature reduced overall performance, but did not modify pacing pattern during a 15-km cycling time trial, regardless of the duration of the exposure.  相似文献   

6.
The addition of whey protein to a carbohydrate–electrolyte drink has been shown to enhance post-exercise rehydration when a volume below that recommended for full fluid balance restoration is provided. We investigated if this held true when volumes sufficient to restore fluid balance were consumed and if differences might be explained by changes in plasma albumin content. Sixteen participants lost ~1.9% of their pre-exercise body mass by cycling in the heat and rehydrated with 150% of body mass lost with either a 60 g · L?1 carbohydrate drink (CHO) or a 60 g · L?1 carbohydrate, 20 g · L?1 whey protein isolate drink (CHO-P). Urine and blood samples were collected pre-exercise, post-exercise, post-rehydration and every hour for 4 h post-rehydration. There was no difference between trials for total urine production (CHO 1057 ± 319 mL; CHO-P 970 ± 334 mL; P = 0.209), drink retention (CHO 51 ± 12%; CHO-P 55 ± 15%; P = 0.195) or net fluid balance (CHO ?393 ± 272 mL; CHO-P ?307 ± 331 mL; P = 0.284). Plasma albumin content relative to pre-exercise was increased from 2 to 4 h during CHO-P only. These results demonstrate that the addition of whey protein isolate to a carbohydrate–electrolyte drink neither enhances nor inhibits rehydration. Therefore, where post-exercise protein ingestion might benefit recovery, this can be consumed without effecting rehydration.  相似文献   

7.
Abstract

Ten healthy, non-cycling trained males (age: 21.2 ± 2.2 years, body mass: 75.9 ± 13.4 kg, height: 178 ± 6 cm, [Vdot]O2PEAK: 46 ± 10 ml · kg?1 · min?1) performed a graded incremental exercise test, two familiarisation trials and six experimental trials. Experimental trials consisted of cycling to volitional exhaustion at 100%, 110% and 120% WPEAK, 60 min after ingesting either 0.3 g · kg?1 body mass sodium bicarbonate (NaHCO3) or 0.1 g · kg?1 body mass sodium chloride (placebo). NaHCO3 ingestion increased cycling capacity by 17% at 100% WPEAK (327 vs. 383 s; P = 0.02) although not at 110% WPEAK (249 vs. 254 s; P = 0.66) or 120% WPEAK (170 vs. 175 s; P = 0.60; placebo and NaHCO3 respectively). Heart rate (P = 0.02), blood lactate (P = 0.001), pH (P < 0.001), [HCO3 ?], (P < 0.001), and base excess (P < 0.001) were greater in all NaHCO3 trials. NaHCO3 attenuated localised ratings of perceived exertion (RPEL) to a greater extent than placebo only at 100% WPEAK (P < 0.02). Ratings of abdominal discomfort and gut fullness were mild but higher for NaHCO3. NaHCO3 ingestion significantly improves continuous constant load cycling at 100% WPEAK due to, in part, attenuation of RPEL.  相似文献   

8.
The varying results reported in response to β-alanine supplementation may be related to the duration and nature of the exercise protocol employed. We investigated the effects of β-alanine supplementation on a wide range of cycling performance tests in order to produce a clear concise set of criteria for its efficacy. Fourteen trained cyclists (Age?=?24.8?±?6.7?years; VO2max?=?65.4?±?10.2 mL·kg·min?1) participated in this placebo-controlled, double-blind study. Prior to supplementation, subjects completed two (familiarization and baseline) supramaximal cycling bouts until exhaustion (120% pre-supplementation VO2max) and two 1-, 4- and 10-km cycling time trial (TT). Subjects then supplemented orally for 4 weeks with 6.4?g/d placebo or β-alanine and repeated the battery of performance tests. Blood lactate was measured pre-exercise, post-exercise and 5 min post-exercise. β-alanine supplementation elicited significant increases in time to exhaustion (TTE) (17.6?±?11.5 s; p?=?0.013, effect compared with placebo) and was likely to be beneficial to 4-km TT performance time (?7.8?±?8.1 s; 94% likelihood), despite not being statistically different (p?=?0.060). Performance times in the 1- and 10-km TT were not affected by treatment. For the highly trained cyclists in the current study, β-alanine supplementation significantly extended supramaximal cycling TTE and may have provided a worthwhile improvement to 4-km TT performance. However, 1- and 10-km cycling TT performance appears to be unaffected by β-alanine supplementation.  相似文献   

9.
Purpose: Correlations between fatigue-induced changes in exercise performance and maximal rate of heart rate (HR) increase (rHRI) may be affected by exercise intensity during assessment. This study evaluated the sensitivity of rHRI for tracking performance when assessed at varying exercise intensities. Method: Performance (time to complete a 5-km treadmill time-trial [5TTT]) and rHRI were assessed in 15 male runners following 1 week of light training, 2 weeks of heavy training (HT), and a 10-day taper (T). Maximal rate of HR increase (measured in bpm·s?1) was the first derivative maximum of a sigmoidal curve fit to HR data recorded during 5 min of running at 8 km·h?1 (rHRI8km·h?1), and during subsequent transition to 13 km·h?1 (rHRI8–13km·h?1) for a further 5 min. Results: Time to complete a 5-km treadmill time-trial was likely slower following HT (effect size ± 90% confidence interval = 0.16 ± 0.06), and almost certainly faster following T (–0.34 ± 0.08). Maximal rate of HR increase during 5 min of running at 8 km·h?1 and rHRI8–13km·h?1 were unchanged following HT and likely increased following T (0.77 ± 0.45 and 0.66 ± 0.62, respectively). A moderate within-individual correlation was found between 5TTT and rHRI8km·h?1 (r value ± 90% confidence interval = –.35 ± .32). However, in a subgroup of athletes (n = 7) who were almost certainly slower to complete the 5TTT (4.22 ± 0.88), larger correlations were found between the 5TTT and rHRI8km·h?1 (r = –.84 ± .22) and rHRI8–13km·h?1 (r = –.52 ± .41). Steady-state HR during rHRI assessment in this group was very likely greater than in the faster subgroup (≥ 1.34 ± 0.86). Conclusion(s): The 5TTT performance was tracked by both rHRI8km·h?1 and rHRI8–13km·h?1. Correlations between rHRI and performance were stronger in a subgroup of athletes who exhibited a slower 5TTT. Individualized workloads during rHRI assessment may be required to account for varying levels of physical conditioning.  相似文献   

10.
Abstract

Individuals with impaired glucose tolerance (IGT) are at greater risk of developing diabetes than in normoglycaemia. The aim of this study was to examine the effects of 12-weeks exercise training in obese humans with IGT. Eleven participants (6 males and 5 females; 49±9 years; mean Body Mass Index (BMI) 32.4 kg · m?2), completed a 12-week brisk walking intervention (30 min per day, five days a week (d · wk?1), at 65% of age-predicted maximal heart rate (HRmax). Anthropometric measurements, dietary intake, pulse wave velocity (PWV, to determine arterial stiffness) and blood pressure (BP) were examined at baseline and post intervention. Fasting blood glucose, glycosylated haemoglobin, insulin, blood lipids, indices of oxidative stress and inflammation (lipid hydroperoxides; superoxide dismutase; multimeric adiponectin concentration and high-sensitivity C-reactive protein) were also determined. Post intervention, PWV (9.08±1.27 m · s?1 vs. 8.39±1.21 m · s?1), systolic BP (145.4±14.5 vs. 135.8±14.9 mmHg), triglycerides (1.52±0.53 mmol . L?1 vs. 1.31±0.54 mmol . L?1), lipid hydroperoxides (1.20±0.47 μM · L?1 vs. 0.79±0.32 μM · L?1) and anthropometric measures decreased significantly (P < 0.05). Moderate intensity exercise training improves upper limb vascular function in obese humans with IGT, possibly by improving triglyceride metabolism, which may subsequently reduce oxidative stress. These changes were independent of multimeric adiponectin modification and alterations in other blood biomarkers.  相似文献   

11.
To assess the effect of carbohydrate and caffeine on gross efficiency (GE), 14 cyclists (V?O2max 57.6 ± 6.3 ml.kg?1.min?1) completed 4 × 2-hour tests at a submaximal exercise intensity (60% Maximal Minute Power). Using a randomized, counter-balanced crossover design, participants consumed a standardised diet in the 3-days preceding each test and subsequently ingested either caffeine (CAF), carbohydrate (CHO), caffeine+carbohydrate (CAF+CHO) or water (W) during exercise whilst GE and plasma glucose were assessed at regular intervals (~30 mins). GE progressively decreased in the W condition but, whilst caffeine had no effect, this was significantly attenuated in both trials that involved carbohydrate feedings (W = ?1.78 ± 0.31%; CHO = ?0.70 ± 0.25%, p = 0.008; CAF+CHO = ?0.63 ± 0.27%, p = 0.023; CAF = ?1.12 ± 0.24%, p = 0.077). Blood glucose levels were significantly higher in carbohydrate ingestion conditions (CHO = 4.79 ± 0.67 mmol·L?1, p < 0.001; CAF+CHO = 5.05 ± 0.81 mmol·L?1, p < 0.001; CAF = 4.46 ± 0.75 mmol·L?1; W = 4.20 ± 0.53 mmol·L?1). Carbohydrate ingestion has a small but significant effect on exercise-induced reductions in GE, indicating that cyclists’ feeding strategy should be carefully monitored prior to and during assessment.  相似文献   

12.
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13.
Dietary intake, vitamin status and oxidative stress were evaluated in 17 elite male boxers. Ten of them frequently reduced body weight rapidly before competitions (Weight Loss Group) and 7 did not practice rapid weight loss (Control Group). Food record checklists, blood samples for determination of vitamin status and plasma glutathione levels were obtained during a week of weight maintenance, a pre-competition week and a post-competition week. The average dietary intakes in both groups were 33 ± 8 kcal·kg?1, 3.7 ± 1.1 g·kg?1 carbohydrates, 1.5 ± 0.4 g·kg?1 protein, 1.2 ± 0.4 g·kg?1 fat and 2.2 ± 1.0 L water per day (excluding pre-competition week in Weight Loss Group). Energy (18 ± 7 kcal·kg?1), carbohydrate (2.2 ± 0.8 g·kg?1), protein (0.8 ± 0.4 g·kg?1), fat (0.6 ± 0.3 g·kg?1) and water (1.6 ± 0.6 L) consumption (P-values <0.001) and intakes of most vitamins (P-values < 0.05) were significantly reduced during the pre-competition week in the Weight Loss Group. In both groups, the intakes of vitamins A, E and folate were below recommended values throughout the three periods; however, blood vitamin and plasma glutathione levels did not change significantly. Our findings indicate a low-caloric and low-carbohydrate diet in elite boxers, regardless of participating in rapid weight loss or not. Apparently, the pre-competitional malnutitrition in the Weight Loss Group did not induce alterations in the vitamin and glutathione status.  相似文献   

14.
Abstract

It has been shown that the critical power (CP) in cycling estimated using a novel 3-min all-out protocol is reliable and closely matches the CP derived from conventional procedures. The purpose of this study was to assess the predictive validity of the all-out test CP estimate. We hypothesised that the all-out test CP would be significantly correlated with 16.1-km road time-trial (TT) performance and more strongly correlated with performance than the gas exchange threshold (GET), respiratory compensation point (RCP) and V?O2 max. Ten club-level male cyclists (mean±SD: age 33.8±8.2 y, body mass 73.8±4.3 kg, V?O2 max 60±4 ml·kg?1·min?1) performed a 10-mile road TT, a ramp incremental test to exhaustion, and two 3-min all-out tests, the first of which served as familiarisation. The 16.1-km TT performance (27.1±1.2 min) was significantly correlated with the CP (309±34 W; r=?0.83, P<0.01) and total work done during the all-out test (70.9±6.5 kJ; r=?0.86, P<0.01), the ramp incremental test peak power (433±30 W; r=?0.75, P<0.05) and the RCP (315±29 W; r=?0.68, P<0.05), but not with GET (151±32 W; r=?0.21) or the V?O2 max (4.41±0.25 L·min?1; r=?0.60). These data provide evidence for the predictive validity and practical performance relevance of the 3-min all-out test. The 3-min all-out test CP may represent a useful addition to the battery of tests employed by applied sport physiologists or coaches to track fitness and predict performance in atheletes.  相似文献   

15.
The main purpose of this study was to compare the effect of the constant load and self-paced exercise with similar total work on autonomic control after endurance exercise. Ten physically active men were submitted to (i) a maximal incremental exercise test, (ii) a 4-km cycling time trial (4-km TT), and (iii) a constant workload test with identical total external work performed at 4-km TT. Gas exchange was measured throughout the tests, while blood lactate, heart rate, and heart rate variability (HRV) were measured during the passive recovery. Power output measured at the last lap (i.e. 3600–4000?m) of 4-km TT (316?±?89?W) was statistically higher than power output measured at the end of the constant workload exercise (211?±?42?W). The 4-km TT produced higher values of blood lactate concentration (8.8?±?2.1?mmol?L?1) than the constant workload test (7.8?±?2.1?mmol?L?1). The heart rate recovery measured at 60?s (constant workload: 37?±?7?bpm; 4-km TT: 30?±?6) and 120?s (constant workload: 57?±?9?bpm; 4-km TT: 51?±?9?bpm) were higher in the constant workload than in the self-paced exercise. The HRV (i.e. RMSSD30s) was statistically higher in the constant load exercise measured at 120, 420, 450, 480, 540, and 570?s than the self-paced exercise. These findings suggest that the autonomic control responses were dependent of the endurance exercise modalities, with parasympathetic activity being delayed after self-paced exercise, as evidenced by post-exercise heart rate indices.  相似文献   

16.
Abstract

In this study, we wished to determine whether the observed reduction in quadriceps muscle oxygen availability, reported during repetitive bouts of isometric exercise in simulated sailing efforts (i.e. hiking), is because of restricted muscle blood flow. Six national-squad Laser sailors initially performed three successive 3-min hiking bouts followed by three successive 3-min cycling tests sustained at constant intensities reproducing the cardiac output recorded during each of the three hiking bouts. The blood flow index (BFI) was determined from assessment of the vastus lateralis using near-infrared spectroscopy in association with the light-absorbing tracer indocyanine green dye, while cardiac output was determined from impedance cardiography. At equivalent cardiac outputs (ranging from 10.3±0.5 to 14.8±0.86 L · min?1), the increase from baseline in vastus lateralis BFI across the three hiking bouts (from 1.1±0.2 to 3.1±0.6 nM · s?1) was lower (P = 0.036) than that seen during the three cycling bouts (from 1.1±0.2 to 7.2±1.4 nM · s?1) (Cohen's d: 3.80 nM · s?1), whereas the increase from baseline in deoxygenated haemoglobin (by ～17.0±2.9 μM) (an index of tissue oxygen extraction) was greater (P = 0.006) during hiking than cycling (by ～5.3±2.7 μM) (Cohen's d: 4.17 μM). The results suggest that reduced vastus lateralis muscle oxygen availability during hiking arises from restricted muscle blood flow in the isometrically acting quadriceps muscles.  相似文献   

17.
We analysed (i) the gender difference in cycling speed and (ii) the age of winning performers in the 508-mile “Furnace Creek 508”. Changes in cycling speeds and gender differences from 1983 to 2012 were analysed using linear, non-linear and hierarchical multi-level regression analyses for the annual three fastest women and men. Cycling speed increased non-linearly in men from 14.6 (s = 0.3) km · h?1 (1983) to 27.1 (s = 0.7) km · h?1 (2012) and non-linearly in women from 11.0 (s = 0.3) km · h?1 (1984) to 24.2 (s = 0.2) km · h?1 (2012). The gender difference in cycling speed decreased linearly from 26.2 (s = 0.5)% (1984) to 10.7 (s = 1.9)% (2012). The age of winning performers increased from 26 (s = 2) years (1984) to 43 (s = 11) years (2012) in women and from 33 (s = 6) years (1983) to 50 (s = 5) years (2012) in men. To summarise, these results suggest that (i) women will be able to narrow the gender gap in cycling speed in the near future in an ultra-endurance cycling race such as the “Furnace Creek 508” due to the linear decrease in gender difference and (ii) the maturity of these athletes has changed during the last three decades where winning performers become older and faster across years.  相似文献   

18.
There is a paucity of studies that have evaluated substrate utilisation and protein catabolism during multiday strenuous exercise in athletes. Eleven well-trained male cyclists completed 3 h of race-simulated cycling on 4 consecutive days. Cyclist exercised 2 h postprandially and with carbohydrate supplementation (~50 g · h?1) during exercise. Whole body substrate utilisation was measured by indirect calorimetry, protein catabolism from sweat and urine urea excretion, and blood metabolite concentration was evaluated. Protein catabolism during exercise was significantly greater on days 2–4 (29.9 ± 8.8; 34.0 ± 11.2; 32.0 ± 7.3 g for days 2, 3, and 4, respectively) compared to day 1 (23.3 ± 7.6 g), P < 0.05. Fat oxidation was greater at 21 km (~45 min) on days 2–4 (1.06 ± 0.23; 1.08 ± 0.25; 1.12 ± 0.29 g · min?1) compared to day 1 (0.74 ± 0.23 g · min?1, P < 0.05), but the rate of carbohydrate and fat oxidation was similar between days at 50 and 80 km. Whole body substrate utilisation is altered on subsequent days of multiday prolonged strenuous cycling that includes a quicker transition to greater fat utilisation from exercise onset and a 28–46% greater reliance on endogenous protein catabolism on all successive days.  相似文献   

19.
Abstract

The study investigated the effect of a school-based healthy lifestyles intervention on physical activity and dietary variables. In total 378 children (177 intervention, 201 control; age 9.75 ± 0.82 years (mean ± s)) took part in the 7-month intervention comprising: preparation for and participation in 3 highlight events (a dance festival, a walking event and a running event); an interactive website for pupils, teachers and parents; and vacation activity planners. Primary outcome measures were objectively measured physical activity (pedometers and accelerometers), endurance fitness and dietary variables. Multi-level modelling was employed for data analysis. The increase in physical activity was greater in the intervention group than the control group (steps: 1049 vs 632 daily steps each month; moderate to vigorous physical activity (MVPA) total: 4.6 min · day?1 · month?1 vs 1.3 min · day?1 · month?1; MVPA bouts: 5.4 min · day?1 · month?1 vs 2.6 min · day?1 · month?1; all P < 0.05). The increase in multi-stage fitness test distance was greater for intervention participants (46 vs 29 m · month?1 of intervention, group × month interaction, P < 0.05). There were no differences between groups in dietary variables, body composition, knowledge of healthy lifestyles or psychological variables. Thus an intervention centred around highlight events and including relatively few additional resources can impact positively on the objectively measured physical activity of children.  相似文献   

20.
The purpose of the present study was to compare acute changes in oxidative stress and inflammation in response to steady state and low volume, high intensity interval exercise (LV-HIIE). Untrained healthy males (n = 10, mean ± s: age 22 ± 3 years; VO2MAX 42.7 ± 5.0 ml · kg?1 · min?1) undertook three exercise bouts: a bout of LV-HIIE (10 × 1 min 90% VO2MAX intervals) and two energy-matched steady-state cycling bouts at a moderate (60% VO2MAX; 27 min, MOD) and high (80% VO2MAX; 20 min, HIGH) intensity on separate days. Markers of oxidative stress, inflammation and physiological stress were assessed before, at the end of exercise and 30 min post-exercise (post+30). At the end of all exercise bouts, significant changes in lipid hydroperoxides (LOOH) and protein carbonyls (PCs) (LOOH (nM): MOD +0.36; HIGH +3.09; LV-HIIE +5.51 and PC (nmol · mg?1 protein): MOD ?0.24; HIGH ?0.11; LV-HIIE ?0.37) were observed. Total antioxidant capacity (TAC) increased post+30, relative to the end of all exercise bouts (TAC (µM): MOD +189; HIGH +135; LV-HIIE +102). Interleukin (IL)-6 and IL-10 increased post+30 in HIGH and LV-HIIE only (P < 0.05). HIGH caused the greatest lymphocytosis, adrenaline and cardiovascular response (P < 0.05). At a reduced energy cost and physiological stress, LV-HIIE elicited similar cytokine and oxidative stress responses to HIGH.  相似文献   

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