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1.
Background: High-intensity interval training (HIIT) has been shown to improve cardiometabolic health during supervised lab-based studies but adherence, enjoyment, and health benefits of HIIT performed independently are yet to be understood. We compared adherence, enjoyment, and cardiometabolic outcomes after 8 weeks of HIIT or moderate-intensity continuous training (MICT), matched for energy expenditure, in overweight and obese young adults. Methods: 17 adults were randomized to HIIT or MICT. After completing 12 sessions of supervised training over 3 weeks, participants were asked to independently perform HIIT or MICT for 30 min, 4 times/week for 5 weeks. Cardiometabolic outcomes included cardiorespiratory fitness (VO2 peak), lipids, and inflammatory markers. Exercise enjoyment was measured by the validated Physical Activity Enjoyment Scale. Results: Exercise adherence (93.4?±?3.1% vs. 93.1?±?3.7%, respectively) and mean enjoyment across the intervention (100.1?±?4.3 vs. 100.3?±?4.4, respectively) were high, with no differences between HIIT and MICT (p?>?.05). Similarly, enjoyment levels did not change over time in either group (p?>?.05). After training, HIIT exhibited a greater decrease in low-density lipoprotein cholesterol than MICT (?0.66?mmol?L?1 vs. ?0.03?mmol?L?1, respectively) and a greater increase in VO2 peak than MICT (p?<?.05, +2.6?mL?kg?min?1 vs. +0.4?mL?kg?min?1, respectively). Interleukin-6 and C-reactive protein increased in HIIT (+0.5?pg?mL?1 and +?31.4?nmol?L?1, respectively) and decreased in MICT (?0.6?pg?mL?1 and ?6.7?nmol?L?1, respectively, p?<?.05). Conclusions: Our novel findings suggest that HIIT is enjoyable and has high unsupervised adherence rates in overweight and obese adults. However, HIIT may be associated with an increase in inflammation with short-term exercise in this population.  相似文献   

2.
Abstract

Exercise is recognized as a frontline therapy for the prevention and treatment of type 2 diabetes (T2D) but the optimal type of exercise is not yet determined. We compared the effects of high-intensity interval training (HIIT) with moderate-intensity continuous training (MICT) for improvement of continuous glucose monitoring (CGM)-derived markers of glycaemic variability, and biomarkers of endothelial cell damage (CD31+ and CD62+ endothelial microparticles (EMPs)) within a population at elevated risk of developing T2D. Fifteen inactive overweight or obese women were randomized to 2 weeks (10-sessions) of progressive HIIT (n?=?8, 4–10X 1-min @ ～90% peak heart rate, 1-min rest periods) or MICT (n?=?7, 20–50?min of continuous activity at ～65% peak heart rate). Prior and three days post-training, fasting blood samples were collected. Both HIIT and MICT improved glycaemic variability as measured by CGM standard deviation (HIIT: 0.82?±?0.39 vs. 0.72?±?0.33?mmol/L; MICT: 0.82?±?0.19 vs. 0.62?±?0.16?mmol/L, pre vs. post) and mean amplitude of glycaemic excursions (MAGE; HIIT: 1.98?±?0.81 vs. 1.41?±?0.90; MICT; 1.98?±?0.43 vs. 1.65?±?0.48, pre vs. post) with no difference between groups. CD62+ EMPs were lower following HIIT (187.7?±?65 vs. 174.9?±?55, pre vs. post) and MICT (170?±?60 vs. 160.3?±?59, pre vs. post) with no difference between groups. There was no change in 24-h mean glucose or CD31+ EMPs. Two weeks of both HIIT or MICT similarly decreased glycaemic variability and CD62+ EMPs in overweight/obese women at elevated risk of T2D.  相似文献   

3.
ABSTRACT

High-intensity interval training (HIIT) has been proposed as a time-efficient exercise protocol to improve metabolic health, but direct comparisons with higher-volume moderate-intensity continuous training (MICT) under unsupervised settings are limited. This study compared low-volume HIIT and higher-volume MICT interventions on cardiometabolic and psychological responses in overweight/obese middle-aged men. Twenty-four participants (age: 48.1±5.2yr; BMI: 25.8±2.3kg·m?2) were randomly assigned to undertake either HIIT (10 X 1-min bouts of running at 80–90% HRmax separated by 1-min active recovery) or MICT (50-min continuous jogging/brisk walking at 65–70% HRmax) for 3 sessions/week for 8 weeks (2-week supervised + 6-week unsupervised training). Both groups showed similar cardiovascular fitness (VO2max) improvement (HIIT: 32.5±5.6 to 36.0±6.2; MICT: 34.3±6.0 to 38.2±5.1mL kg?1 min?1, p < 0.05) and %fat loss (HIIT: 24.5±3.4 to 23.2±3.5%; MICT: 23.0±4.3 to 21.5±4.1%, p< 0.05) over the 8-week intervention. Compared to baseline, MICT significantly decreased weight and waist circumference. No significant group differences were observed for blood pressure and cardiometabolic blood markers such as lipid profiles, fasting glucose and glycated haemoglobin. Both groups showed similar enjoyment levels and high unsupervised adherence rates (>90%). Our findings suggest that low-volume HIIT can elicit a similar improvement of cardiovascular fitness as traditional higher-volume MICT in overweight/obese middle-aged men.  相似文献   

4.
This study compared the effects of 12-week sprint interval training (SIT), high-intensity interval training (HIIT), and moderate-intensity continuous training (MICT) on cardiorespiratory fitness (V?O2peak), body mass and insulin sensitivity in overweight females. Forty-two overweight women (age 21.2 ± 1.4 years, BMI 26.3 ± 2.5 kg·m?2) were randomized to the groups of SIT (80 × 6-s sprints + 9-s rest), and isoenergetic (300KJ) HIIT (~9 × 4-min cycling at 90% V?O2peak + 3-min rest) and MICT (cycling at 60% V?O2peak for ~ 61-min). Training intervention was performed 3 d·week?1 for 12 weeks. After intervention, all three groups induced the same improvement in V?O2peak (~ +25%, p < 0.001) and a similar reduction in body mass (~ – 5%, p < 0.001). Insulin sensitivity and fasting insulin levels were improved significantly on post-training measures in SIT and HIIT by ~26% and ~39% (p < 0.01), respectively, but remain unchanged in MICT. In contrast, fasting glucose levels were only reduced with MICT (p < 0.01). The three training strategies are equally effective in improving V?O2peak and reducing body mass, however, the SIT is time-efficient. High-intensity training (i.e. SIT and HIIT) seems to be more beneficial than MICT in improving insulin sensitivity.

Abbreviations: BMI: body mass index; CVD: cardiovascular disease; HIEG: hyperinsulinaemic euglycaemic glucose; HIIT: high-intensity interval training; HOMA-IR: homeostasis model assessment of insulin resistance; HR: heart rate; MICT: moderate-intensity continuous training; RPE: ratings of perceived exertion; SIT: sprint interval training; T2D: type 2 diabetes; V?O2peak: peak oxygen consumption  相似文献   


5.
The purpose of this study was to compare the effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) utilizing a canoeing ergometer on endurance determinants, as well as aerobic and anaerobic performances among flat-water canoeists. Fourteen well-trained male flat-water canoeists were divided into an HIIT group or an MICT group. All subjects performed a continuous graded exercise test (GXT) and three fixed-distance (200, 500, and 1000?m) performance tests on a canoeing ergometer to determine canoeing economy, peak oxygen uptake (VO2peak), and power at VO2peak, and to calculate the critical velocity (CV) and anaerobic work capacity before and after the training programmes. The training programme involved training on a canoeing ergometer three times per week for four weeks. HIIT consisted of seven 2 min canoeing bouts at an intensity of 90% VO2peak separated by 1 min of rest. The MICT group was trained at an intensity of 65% VO2peak continuously for 20 min. After four weeks of training, performance in the 200-m distance test and the power at VO2peak significantly improved in the HIIT group; performance in the 500?m and 1000?m distances and CV significantly improved in the MICT group. However, all variables were not significantly different between groups. It is concluded that HIIT for four weeks is an effective training strategy for improvement of short-distance canoeing performance. In contrast, MICT improves middle-distance canoeing performances and aerobic capacity.  相似文献   

6.
The main purpose of this study was to evaluate running kinematic characteristics and foot strike patterns (FSP) during early and late stages of actual and common high-intensity intermittent training (HIIT): 5 × 2000 m with 120-s recovery between runs. Thirteen healthy, elite, highly trained male endurance runners participated in this study. They each had a personal record in the half-marathon of 70 ± 2.24 min, and each had a minimum experience of 4 years of training and competition. Heart rate (HR) and rate of perceived exertion (RPE) were monitored during HIIT. High levels of exhaustion were reached by the athletes during HIIT (HRpeak: 174.30 bpm; RPE: 17.23). There was a significant increase of HRpeak and RPE during HIIT; nevertheless, time for each run remained unchanged. A within-protocol paired t-test (first vs. last run) revealed no significant changes (P ≥ 0.05) in kinematics variables and FSP variables during HIIT. There were no substantial changes on kinematics and FSP characteristics in endurance runners after fatigue induced by a HIIT. Only the minimum ankle alignment showed a significant change. The author suggests that these results might be due to both the high athletic level of participants and their experience in HIIT.  相似文献   

7.
Abstract

The purpose of the present study was to determine the effects of 10-in [025–m] versus 16-in [0.41-m] wheelchair handrims on cardiorespiratory and psychophysiological exercise responses during wheelchair propulsion at selected velocities. Fifteen male paraplegics (27.0 ± 5.5 yrs) performed three discontinuous exercise tests (ACE = arm crank ergometer; WERG = wheelchair roller ergometer) and two 1600-m performance-based track trials (TRACK) under simulated race conditions. There were no significant differences in HR, VO2, VE, HLa, or category-ratio ratings of perceived exertion (RPE) using different handrims during wheelchair propulsion at 4 km-h1. In contrast, at 8 km-h?1 subjects demonstrated a 13% lower steady state VO2 (p < .05) using the 10-in handrims, coincident with a 23% lower VE Steady state HR during WERG at 8 km-h?1 using the 10-in (124.4 ± 39 b.min?1) or 16-in (130.6 ± 4.6 b.min?1) handrims were not significantly different. There were also no significant differences between ACE or WERG conditions during maximal effort for VO2 or VE. However, HRpeak during ACE was 7% higher than HRpeak during WERG16 (183 ± 15 b.min?1 vs. 171 ± 12 b.min?1, p < .05), and whole blood HLa during ACE was also significantly higher (by 2.3-2.5 mmol; p < .05) compared to WERG. There were no significant differences for HR, performance time, or RPE between trials using different handrim diameters during the 1600-m event. In contrast, HLa was significantly lower using smaller handrims (9.9 mmol) compared with larger handrims (11.3 mmol), paralleling a similar difference in the laboratory. Although these data demonstrated few significant differences of physiologic responses between trials using different handrims, there was a tendency for a lower metabolic stress using the smaller handrims.  相似文献   

8.
BackgroundIt remains unclear whether studies comparing maximal oxygen uptake (VO2max) response to sprint interval training (SIT) vs. moderate-intensity continuous training (MICT) are associated with a high risk of bias and poor reporting quality. The purpose of this study was to evaluate the risk of bias and quality of reporting in studies comparing changes in VO2max between SIT and MICT.MethodsWe conducted a comprehensive literature search of 4 major databases: AMED, CINAHL, EMBASE, and MEDLINE. Studies were excluded if participants were not healthy adult humans or if training protocols were unsupervised, lasted less than 2 weeks, or utilized mixed exercise modalities. We used the Cochrane Collaboration tool and the CONSORT checklist for non-pharmacological trials to evaluate the risk of bias and reporting quality, respectively.ResultsTwenty-eight studies with 30 comparisons (3 studies included 2 SIT groups) were included in our meta-analysis (n = 360 SIT participants: body mass index (BMI) = 25.9 ± 3.7 kg/m2, baseline VO2max = 37.9 ± 8.0 mL/kg/min; n = 359 MICT participants: BMI = 25.5 ± 3.8 kg/m2, baseline VO2max = 38.3 ± 8.0 mL/kg/min; all mean ± SD). All studies had an unclear risk of bias and poor reporting quality.ConclusionAlthough we observed a lack of superiority between SIT and MICT for improving VO2max (weighted Hedge's g = ?0.004, 95% confidence interval (95%CI): ?0.08 to 0.07), the overall unclear risk of bias calls the validity of this conclusion into question. Future studies using robust study designs are needed to interrogate the possibility that SIT and MICT result in similar changes in VO2max.  相似文献   

9.
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10.
ABSTRACT

This study examined changes in enjoyment, affective valence, and rating of perceived exertion (RPE) in obese women performing two regimes of high intensity interval training (HIIT) differing in structure and volume. Nineteen obese and inactive women (age and body mass index?=?37.5?±?10.5?yr and 39.0?±?4.3?kg/m2) were randomized to 6?wk of traditional (TRAD, n?=?10) or periodized interval training (PER, n?=?9) which was performed on a cycle ergometer during which structure changed weekly. Two supervised sessions per week were performed in a lab, and one session per week was performed unsupervised. During every lab-based session, perceptual responses including enjoyment, affective valence, and RPE were acquired. Data showed a groupXtraining interaction for enjoyment (p?=?0.02) which was lower by 10–25 units during PER versus TRAD. In addition, there was a groupXtimeXtraining interaction for RPE (p?=?0.01). RPE did not change in response to TRAD yet varied during PER, with lower RPE values exhibited during brief supramaximal bouts (6.3?±?0.9) compared to longer intervals (7.3?±?1.2). Both regimes showed reductions in affective valence during training, with the lowest values equal to 1.5?±?1.6 in TRAD and ?0.2?±?1.6 in PER. Compared to TRAD, more aversive responses were shown in PER throughout training by 0.4–2.0 units. Data show lower enjoyment and more aversive responses to higher-volume bouts of interval training, which suggests that shorter bouts may be perceived more favourably by obese women.  相似文献   

11.
Purpose: To determine if: (i) mean power output and enjoyment of high-intensity interval training (HIIT) are enhanced by virtual-reality (VR)-exergaming (track mode) compared to standard ergometry (blank mode), (ii) if mean power output of HIIT can be increased by allowing participants to race against their own performance (ghost mode) or by increasing the resistance (hard mode), without compromising exercise enjoyment.

Methods: Sixteen participants (8 males, 8 females, VO2max: 41.2?±?10.8 ml?1·kg?1·min?1) completed four VR-HIIT conditions in a partially-randomised cross-over study; (1a) blank, (1b) track, (2a) ghost, and (2b) hard. VR-HIIT sessions consisted of eight 60 s high-intensity intervals at a resistance equivalent to 70% (77% for hard) maximum power output (PMAX), interspersed by 60 s recovery intervals at 12.5% PMAX, at a self-selected cadence. Expired gases were collected and VO2 measured continuously. Post-exercise questionnaires were administered to identify differences in indices related to intrinsic motivation, subjective vitality, and future exercise intentions.

Results: Enjoyment was higher for track vs. blank (difference: 0.9; 95% CI: 0.6, 1.3) with no other differences between conditions. There was no difference in mean power output for track vs. blank, however it was higher for track vs. ghost (difference: 5 Watts; CI: 3, 7), and hard vs. ghost (difference: 19 Watts; 95% CI: 15, 23).

Conclusions: These findings demonstrate that VR-exergaming is an effective intervention to increase enjoyment during a single bout of HIIT in untrained individuals. The presence of a ghost may be an effective method to increase exercise intensity of VR-HIIT.  相似文献   

12.
The purpose of this study was to evaluate two practical interval training protocols on cardiorespiratory fitness, lipids and body composition in overweight/obese women. Thirty women (mean ± SD; weight: 88.1 ± 15.9 kg; BMI: 32.0 ± 6.0 kg · m2) were randomly assigned to ten 1-min high-intensity intervals (90%VO2 peak, 1 min recovery) or five 2-min high-intensity intervals (80–100% VO2 peak, 1 min recovery) or control. Peak oxygen uptake (VO2 peak), peak power output (PPO), body composition and fasting blood lipids were evaluated before and after 3 weeks of training, completed 3 days per week. Results from ANCOVA analyses demonstrated no significant training group differences for any primary variables (P > 0.05). When training groups were collapsed, 1MIN and 2MIN resulted in a significant increase in PPO (?18.9 ± 8.5 watts; P = 0.014) and time to exhaustion (?55.1 ± 16.4 s; P = 0.001); non-significant increase in VO2 peak (?2.36 ± 1.34 ml · kg?1 · min?1; P = 0.185); and a significant decrease in fat mass (FM) (??1.96 ± 0.99 kg; P = 0.011). Short-term interval exercise training may be effective for decreasing FM and improving exercise tolerance in overweight and obese women.  相似文献   

13.
ABSTRACT

Introduction: High-Intensity Interval Training (HIIT) and Constant-Intensity Endurance Training (CIET) improves peak oxygen uptake (V?O2) similarly in adults; but in children this remains unclear, as does the influence of maturity. Methods: Thirty-seven boys formed three groups: HIIT (football; n = 14; 14.3 ± 3.1 years), CIET (distance runners; n = 12; 13.1 ± 2.5 years) and a control (CON) group (n = 11; 13.7 ± 3.2 years). Peak V?O2 and gas exchange threshold (GET) were determined from a ramp test and anaerobic performance using a 30 m sprint pre-and-post a three-month training cycle. Results: The HIIT groups peak V?O2 was significantly higher than the CON group pre (peak V?O2: 2.54 ± 0.63 l·min-1 vs 2.03 ± 0.53 l·min-1, d = 0.88; GET: 1.41 ± 0.26 l·min-1 vs 1.13 ± 0.29 l·min-1, d = 1.02) and post-training (peak V?O2: 2.63 ± 0.73 l·min-1 vs 2.08 ± 0.64 l·min-1, d = 0.80; GET: 1.32 ± 0.33 l·min-1 vs 1.15 ± 0.38 l·min-1, d = 0.48). All groups showed a similar magnitude of change during the training (p > 0.05). Conclusion: HIIT was not superior to CIET for improving aerobic or anaerobic parameters in adolescents. Secondly, pre- and post-pubertal participants demonstrated similar trainability.  相似文献   

14.

Background and aim

This study examined the effects of a 6-week high-intensity interval training (HIIT) vs. low-intensity endurance training (LOW), applied during physical education on motor performance, mood and perceived exertion.

Methods

Over a period of 6 weeks, 85 pupils (34 male; 51 female; age: 11.9?±?0.9 years) performed 11 sessions of either HIIT (20?min, intervals from 10?s to 4?min at about 90–100% of average running speed of 6?min run [vmean]) or LOW (30?min, intervals from 6–25?min at about 65–85% vmean). Before and after the 6?week intervention each pupils’ anthropometry and motor performance (20?m sprint, standing long-jump, lateral jumping from side to side, push-ups, sit-ups, 6?min run) were assessed. Session rating of perceived exertion (RPE) was recorded after each session and mood was assessed by questionnaire following the 3rd, 6th, 9th and 11th session.

Results

RPE (p?<?0.05) was higher and mood more positive (p?<?0.05) with HIIT compared to LOW. Performances in the 6?min run (p?<?0.001; part. η2?=?0.473), 20?m sprint (p?<?0.001; part. η2?=?0.226), standing long-jump (p?<?0.05; part. η2?=?0.056), push-ups (p?<?0.001; part. η2?=?0.523) and sit-ups (p?<?0.001; part. η2?=?0.146) improved following HIIT and LOW with no significant time?×?group interaction (except for the sit-ups [p?<?0.05; part. η2?=?0.048]).

Conclusions

HIIT and LOW improved the performances in 6?min run, 20?m sprint, standing long-jump and push-ups similarly. However, the improvements in HIIT compared to LOW were achieved in 30% less time. As time is limited in physical education classes, HIIT offers a new perspective for improving endurance and motor performance in children. The positive mood associated with HIIT demonstrates the applicability in physical education.
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15.
VO2 fluctuations are argued to be an important mechanism underpinning chronic adaptations following interval training. We compared the effect of exercise modality, continuous vs. intermittent realized at a same intensity, on electrical muscular activity, muscular oxygenation and on whole body oxygen uptake. Twelve participants (24?±?5 years; VO2peak: 43?±?6?mL·?min?1·kg?1) performed (i) an incremental test to exhaustion to determine peak work rate (WRpeak); two randomized isocaloric exercises at 70%WRpeak; (ii) 1 bout of 30 min; (iii) 30 bouts of 1?min work intercepted with 1?min passive recovery. For electromyography, only the CON exercise showed change for the vastus lateralis root-mean-square (+6.4?±?5.1%, P?P?vs. 2.32?±?1.21?mM, respectively, for the CON and INT, P?vs. 356?±?301?sec, respectively, for the CON and INT, P?相似文献   

16.
The aim of this study was to compare the effects of two different intensity distribution training programmes (polarized (POL) and threshold (THR)) on aerobic performance, strength and body composition variables in ultra-endurance runners. Twenty recreationally trained athletes were allocated to POL (n?=?11; age: 40.6?±?9.7 years; height: 175.4?±?7?cm; weight: 73.5?±?10.8?kg; fat mass 18.4?±?6.0%; VO2max: 55.8?±?4.9?ml/kg/min) or THR group (n?=?9; age: 36.8?±?9.2 years; height: 178.5?±?4.2?cm; weight: 75.5?±?10.4?kg; fat mass 14.9?±?5.3%; VO2max: 57.1?±?5.2?ml/kg/min) and performed the 12 weeks training programme. Both programmes had similar total time and load but a different intensity distribution (POL?=?79.8?±?2.1% in Zone 1; 3.9?±?1.9% in Zone 2; 16.4?±?1.5% in Zone 3; THR?=?67.2?±?4.6% in Zone 1; 33.8?±?4.6% in Zone 2; 0% in Zone 3). Body composition, isokinetic strength and aerobic running performance were measured before and after each programme. Both groups decreased fat mass after training (POL= Δ–11.2%; p?=?.017; ES?=?0.32; THR= Δ–18.8%; p?p?=?0.003; ES?=?0.71) and 12?km/h (Δ–4.5%; p?=?.026; ES?=?0.73) and running time to exhaustion (Δ2.4%; p?=?.011; ES?=?0.33). No changes were observed in strength and no significant differences were observed between the group in any variable. Compared with THR distribution, 12 weeks of POL training efficiently improves aerobic performance in recreational ultra-endurance runners.  相似文献   

17.
This study (1) compared the physiological responses and performance during a high-intensity interval training (HIIT) session incorporating externally regulated (ER) and self-selected (SS) recovery periods and (2) examined the psychophysiological cues underpinning SS recovery durations. Following an incremental maximal exercise test to determine maximal aerobic speed (MAS), 14 recreationally active males completed 2 HIIT sessions on a non-motorised treadmill. Participants performed 12?×?30?s running intervals at a target intensity of 105% MAS interspersed with 30?s (ER) or SS recovery periods. During SS, participants were instructed to provide themselves with sufficient recovery to complete all 12 efforts at the required intensity. A semi-structured interview was undertaken following the completion of SS. Mean recovery duration was longer during SS (51?±?15?s) compared to ER (30?±?0?s; p?d?=?1.46?±?0.46). Between-interval heart rate recovery was higher (SS: 19?±?9?b?min?1; ER: 8?±?5?b?min?1; p?d?=?1.43?±?0.43) and absolute time ≥90% maximal heart rate (HRmax) was lower (SS: 335?±?193?s; ER: 433?±?147?s; p?=?.075; d?=?0.52?±?0.39) during SS compared to ER. Relative time ≥105% MAS was greater during SS (90?±?6%) compared to ER (74?±?20%; p?d?=?0.87?±?0.40). Different sources of afferent information underpinned decision-making during SS. The extended durations of recovery during SS resulted in a reduced time ≥90% HRmax but enhanced time ≥105% MAS, compared with ER exercise. Differences in the afferent cue utilisation of participants likely explain the large levels of inter-individual variability observed.  相似文献   

18.
Abstract

The purpose of this investigation was to compare the peak physiological responses among four protocols that employed different amounts of handweighted exercise in 16 males (aged 26.3 ± 4.1 years). The four protocols were (a) uphill treadmill running (UR; 3.36 m-s1, 2.5% grade increase-3 min1); (b) uphill treadmill walking while pumping 1.36kg handweights (HW) (UWHW; 1.79ms1, 5.0% grade increase-3 min1; (c) treadmill walking while pumping .91-kg HW (WHW; 1.79 m-s1, 0% grade, .91kg HW increase-3 min1); and (d) standing in place and pumping HW (SHW; arm work as described in WHW). It was hypothesized that the peak responses would be inversely proportional to the estimated muscle mass activated (i.e., UR = UWHW > WHW > SHW). Dependent variables included peak oxygen uptake (VO2 peak), peak heart rate (HRpeak), peak ventilation (Vepeak), and peak respiratory exchange ratio (RERpeak). No differences were noted between UR and UWHW with respect to any of the dependent variables. All variables (except RERpeak) were greater (p < .01) in UR and UWHW than either WHW or SHW. RERpeak was greater (p < .01) in UR and UWHW than in WHW. VO2peak and HRpeak were greater (p < .01) in WHW when compared to SHW. Mean VO2peak was 97.5, 69.7, and 60% of UR for UWHW, WHW, and SHW, respectively. Therefore, walking and pumping handweights provides a maximal stimulus to the oxygen transport system.  相似文献   

19.
The effectiveness of a nap as a recovery strategy for endurance exercise is unknown and therefore the present study investigated the effect of napping on endurance exercise performance. Eleven trained male runners completed this randomised crossover study. On two occasions, runners completed treadmill running for 30?min at 75% ?O2max in the morning, returning that evening to run for 20?min at 60% ?O2max, and then to exhaustion at 90% ?O2max. On one trial, runners had an afternoon nap approximately 90?min before the evening exercise (NAP) whilst on the other, runners did not (CON). All runners napped (20?±?10?min), but time to exhaustion (TTE) was not improved in all runners (NAP 596?±?148?s vs. CON 589?±?216?s, P?=?.83). Runners that improved TTE after the nap slept less at night than those that did not improve TTE (night-time sleep 6.4?±?0.7?h vs. 7.5?±?0.4?h, P?r2 ? =??0.76, P?=?.001). In runners that improved TTE, ratings of perceived exertion (RPE) were lower during the TTE on NAP than CON compared to runners that did not improve (?0.4?±?0.6 vs. 0?±?0, P?=?.05). Reduced exercising sense of effort (RPE) may account for the improved TTE after the nap. In conclusion, a short afternoon nap improves endurance performance in runners that obtain less than 7?h night-time sleep.  相似文献   

20.
The aim of this study was to determine the effects of caffeine ingestion on a ‘preloaded’ protocol that involved cycling for 2?min at a constant rate of 100% maximal power output immediately followed by a 1-min ‘all-out’ effort. Eleven male cyclists completed a ramp test to measure maximal power output. On two other occasions, the participants ingested caffeine (5?mg?·?kg?1) or placebo in a randomized, double-blind procedure. All tests were conducted on the participants' own bicycles using a Kingcycle? test rig. Ratings of perceived exertion (RPE; 6–20 Borg scale) were lower in the caffeine trial by approximately 1 RPE point at 30, 60 and 120?s during the constant rate phase of the preloaded test (P?<0.05). The mean power output during the all-out effort was increased following caffeine ingestion compared with placebo (794±164 vs 750±163?W; P?=?0.05). Blood lactate concentration 4, 5 and 6?min after exercise was also significantly higher by approximately 1?mmol?·?l?1 in the caffeine trial (P?<0.05). These results suggest that high-intensity cycling performance can be increased following moderate caffeine ingestion and that this improvement may be related to a reduction in RPE and an elevation in blood lactate concentration.  相似文献   

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