The effects of ice vest pre-cooling on skin blood flow at rest and during exercise in the heat

© 2015 The Authors. Published by BMC. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.1186/2046-7648-4-S1-A127Ice vest pre-cooling has been show to lower rectal temperature during intermittent exercise in hot conditions but only after 40 min of exercise [1]. The authors suggested that the ice vest may have initiated a strong local cutaneous vasoconstrictor response reducing skin blood flow [2] and thus the cooling potential, until increases in body temperature and skin blood flow occurred later in exercise. Therefore, the purpose of this study was to determine whether ice vest pre-cooling reduces skin blood flow during intermittent exercise in the heat compared to a no cooling control.Published versio

Wearing colored glasses can influence the exercise performance and testosterone concentration

Perception of red color is associated with higher testosterone concentration and better human performance. Thus, we evaluated the acute effects of wearing colored-lens glasses on the YoYo intermittent endurance exercise test 2 (YoYoIE2) performance indicators and testosterone concentration. Ten soccer players performed three YoYoIE2 (counterbalanced crossover) wearing colorless (control), blue- or red-lensed glasses (2–4 days of rest in between). YoYoIE2 performance did not differ among the trials (p>0.05), but blood testosterone increased post-exercise in red compared to red baseline (red=14%, effect size=0.75). Analysis showed faster heart rate recovery (p0.05) among the trials. Wearing red-colored lenses during high-intensity intermittent exercise increased testosterone concentration, but do not influence performance

Effects of oral creatine supplementation on high intensity, intermittent exercise performance in competitive squash players

The purpose of this study was to determine the effects of oral creatine supplementation on high intensity, intermittent exercise performance in competitive squash players. Nine squash players (mean ± SEM V˙O2max = 61.9 ± 2.1ml · kg-1 · min-1; body mass = 73 ± 3 kg) performed an on-court “ghosting” routine that involved 10 sets of 2 repetitions of simulated positional play, each set interspersed with 30 s passive recovery. A double blind, crossover design was utilised whereby experimental and control groups supplemented 4 times daily for 5 d with 0.075 g · kg-1 body mass of creatine monohydrate and maltodextrine, respectively, and a 4 wk washout period separated the crossover of treatments. The experimental group improved mean set sprint time by 3.2 ± 0.8 % over and above the changes noted for the control group (P = 0.004 and 95 % Cl = 1.4 to 5.1 %). Sets 2 to 10 were completed in a significantly shorter time following creatine supplementation compared to the placebo condition (P < 0.05). In conclusion, these data support existing evidence that creatine supplementation improves high intensity, intermittent exercise performance. In addition, the present study provides new evidence that oral creatine supplementation improves exercise performance in competitive squash players

The influence of voluntary upper body exercise on the performance of stimulated paralysed human quadriceps

In this study the influence of voluntary upper body exercise on the performance of stimulated paralysed human quadriceps was investigated in five subjects with spinal cord lesions in the thoracic spine. The experimental setup consisted of computer-controlled stimulation of the quadriceps using electrodes on the surface of the skin, a dynamometer for isometric or isokinetic loading of the lower leg, and a rowing ergometer for upper body exercise. In all subjects, quadriceps fatigue tests were conducted to study the influence of upper body exercise on knee torque during sustained continuous or intermittent stimulation of quadriceps. The relative asymptotic torque appeared to be significantly higher with the presence of upper body exercise than without. This was consistently found both between trials (starting with or without upper body exercise) as well as within trials, when upper body exercise was started or stopped during the trial. No significant influence of upper body exercise on the time constant of initial torque decline was found

The influence of intense intermitent versus moderate continuous exercise on postprandial lipemia

INTRODUCTION: Postprandial lipemia is characterized by an increased concentration of circulating lipids after fat intake and is an independent risk factor for cardiovascular disease. Exercise is known to reduce postprandial lipemia and its negative clinical outcomes. OBJECTIVE: This study investigated the effect of intense intermittent versus moderate continuous exercise using the same energy expenditure in postprandial lipemia. MATERIALS AND METHODS: Twenty healthy men (aged 21.5 + 3.5 years) performed a random sequence of either rest or 500 Kcal tests separated by a minimum 48 h interval as follows: (a) no exercise (control), (b) intense intermittent exercise, or (c) moderate continuous exercise. Each test series was completed 30 min before ingestion of a high-fat meal (1 g fat/kg). Venous blood was collected before and at 1, 2, 3 and 4 hours after the high-fat meal. Postprandial lipemia was assessed using the area under the curve approach as well as a kinetic profile of mean lipid variables. Statistical significance was tested at the p<0.05 level. RESULTS: With both statistical approaches, intense intermittent and moderate continuous exercises were both effective in reducing postprandial triglycerides; however, only intense intermittent exercise reduced the levels of postprandial very low density lipoprotein. Intense intermittent and continuous exercise produced lower levels of insulinemia using the area under the curve analysis only. CONCLUSION: Intense intermittent or continuous exercise with an energy expenditure of 500 kcal completed 30 min before ingestion of high-fat meal reduced postprandial lipid levels to different levels in physically active men. Understanding these relevant differences will enable clinicians to provide the best exercise prescription for patients

Effectiveness of short-term heat acclimation on intermittent exercise in thermoneutral and hot environments

It is well-established that repetition of heat stress exposure has been shown to facilitate adaptations to the heat but these protocols have tended to be of a fixed work intensity, continuous exercise, long-term in duration (>7 days) and use hydration. Secondly, there is limited information on the potential use of heat acclimation as a training method for human performance in thermoneutral conditions. Therefore, the aims of this study were to investigate the effectiveness of short-term heat acclimation (STHA) for 5 days, using the controlled hyperthermia technique with dehydration, on intermittent exercise in thermoneutral and hot environments

Effects of intermittent bouts of aerobic exercise on oxygen consumption during and after exercise

The purpose of this study was to compare the oxygen consumption (VO2) and energy expenditure (EE) during and after exercise between a single bout of continuous exercise and intermittent bouts of exercise, which of equivalent exercise intensity and total exercise duration. Nine healthy young men performed the following two exercise trials on separate days: 1) A single bout of 30-min exercise (30Ex), followed by 90-min of rest. 2) Three intermittent bouts of 30-min exercise, separated by a 10-min rest between exercise bouts (10Ex), followed by 70-min of rest. That is, the total rest in two trials was 90-min. Each exercise was performed with a cycle ergometer at 60% of VO2max. The expired gases were monitored continuously to determine VO2 and EE by a breath-by-breath method throughout the trial period. For average VO2, total VO2, and EE during exercise, no significant difference was observed between the two trials, however, total VO2, EE, excess post-exercise oxygen consumption during rest were significantly greater in 10Ex than in 30Ex (p＜0.05). These results suggests that the intermittent bouts of aerobic exercise can contribute to greater the total VO2 and EE after exercise compared with a continuous exercise of equivalent total exercise duration

Carbohydrate gel ingestion significantly improves the intermittent endurance capacity, but not sprint performance, of adolescent team games players during a simulated team games protocol

The aim of this study was to investigate the influence of ingesting a carbohydrate (CHO) gel on the intermittent endurance capacity and sprint performance of adolescent team games players. Eleven participants [mean age 13.5 ± 0.7 years, height 1.72 ± 0.08 m, body mass (BM) 62.1 ± 9.4 kg] performed two trials separated by 3–7 days. In each trial, they completed four 15 min periods of part A of the Loughborough Intermittent Shuttle Test (LIST), followed by an intermittent run to exhaustion (part B). In the 5 min pre-exercise, participants consumed 0.818 mL kg−1 BM of a CHO or a non-CHO placebo gel, and a further 0.327 mL kg−1 BM every 15 min during part A of the LIST (38.0 ± 5.5 g CHO h−1 in the CHO trial). Intermittent endurance capacity was increased by 21.1% during part B when the CHO gel was ingested (4.6 ± 2.0 vs. 3.8 ± 2.4 min, P < 0.05, r = 0.67), with distance covered in part B significantly greater in the CHO trial (787 ± 319 vs. 669 ± 424 m, P < 0.05, r = 0.57). Gel ingestion did not significantly influence mean 15 m sprint time (P = 0.34), peak sprint time (P = 0.81), or heart rate (P = 0.66). Ingestion of a CHO gel significantly increases the intermittent endurance capacity of adolescent team games players during a simulated team games protocol

Effect of an Iso-intense Continuous and Intermittent Training Programme on VO2 Max and Anthropometric Profile of Sedentary Males

The purpose of this study was to investigate the effectiveness of an iso-intense continuous and intermittent training program on maximum aerobic capacity ( O2 max) and other anthopometric profiles, like, body mass index (BMI) and fat mass of sedentary males. 24 healthy sedentary males of 21.8±3.7years participated in this study. They were divided into 3 groups, like, control group (n=9), continuous training group (n=7) and intermittent training group (n=8). Exercise group performed the training 3 days per week up to 12 week.The study was approved by ethical committee of the UniversitiSains Malaysia, KubangKerian, Kelantan, Malaysia. O2 max of each individual was determined following a graded exercise protocol to exhaustion, on an Excalibur Lode Cycle ergometer. For continuous exercise, subjects cycledat 60% of individual O2 max for 45 minute on an ergometer. In intermittent training, the subjects cycled at 45% of individual O2 max for 10 min followed by 5 min rest and then at 75% of individual O2 max for 10 min followed by 5 min rest. This repetition continued until 45 min. Both the training programme were madeiso-intense. The relative O2max of both the continuous and intermittent training groups improved significantly, but the degree of improvement was more in intermittent training programme. No improvement was observed in BMI. Regular physical activity is a part of healthy lifestyle that is known to reduce risk of cardiovascular disease. Hence, in conclusion, our study indicated a beneficial effect of exercise training in improving the cardiorespiratory fitness ( O2 max), through continuous and intermittent training programme

Effect of supervised exercise on physical function and balance in patients with intermittent claudication

Background The aim of the study was to identify whether a standard supervised exercise programme (SEP) for patients with intermittent claudication improved specific measures of functional performance including balance. Methods A prospective observational study was performed at a single tertiary vascular centre. Patients with symptomatic intermittent claudication (Rutherford grades 1–3) were recruited to the study. Participants were assessed at baseline (before SEP) and 3, 6 and 12 months afterwards for markers of lower-limb ischaemia (treadmill walking distance and ankle : brachial pressure index), physical function (6-min walk, Timed Up and Go test, and Short Physical Performance Battery (SPPB) score), balance impairment using computerized dynamic posturography with the Sensory Organization Test (SOT), and quality of life (VascuQoL and Short Form 36). Results Fifty-one participants underwent SEP, which significantly improved initial treadmill walking distance (P = 0·001). Enrolment in a SEP also resulted in improvements in physical function as determined by 6-min maximum walking distance (P = 0·006), SPPB score (P &lt; 0·001), and some domains of both generic (bodily pain, P = 0·025) and disease-specific (social domain, P = 0·039) quality of life. Significant improvements were also noted in balance, as determined by the SOT (P &lt; 0·001). Conclusion Supervised exercise improves both physical function and balance impairment