Lack of a Dose Response from 7 Days of Ischemic Preconditioning in Moderately trained Cyclists.

Ischemic preconditioning (IP) has a small benefit on exercise performance, but differences in the IP method, performance tasks and exercise modality have made providing practical coach guidelines difficult. We investigated the performance-enhancing effects of IP on cyclists by comparing the frequency of IP application over a 7-day period. Using a randomized, sham-controlled, single-blinded experiment, 24 competitive age-group track cyclists (38±12 years) were assigned to one of three twice-daily (sham: 20 and 20 mmHg; once-a-day: 20 and 220 mmHg; twice-a-day: 220 and 220 mmHg) IP leg protocols (4 × 5 min ischemia/5 min reperfusion alternating between legs) over seven consecutive days. A 4000-m cycling-ergometer time trial was completed before, immediately following and one week after the protocols. Neither mean power, nor 4000-m performance time nor VO 2 were significantly affected by either of the IP protocols compared to the sham at any time point following treatment. Repeated application of IP over seven days did not enhance the performance of trained cyclists in a 4000-m laboratory time trial. More research is required to understand how changes to methodological variables can improve the chances of IP successfully enhancing athlete performance.

The effect of 1 week of repeated ischaemic leg preconditioning on simulated Keirin cycling performance: a randomised trial.

BACKGROUND: Coaches continually seek new ways of doing things and also refine existing techniques to improve sporting performance. Coaches are currently experimenting using ischaemic preconditioning (IPC) over consecutive days in the hope of improving competitive performances. AIMS: First, to quantify the physiological impact of 1 week of IPC on simulated Keirin cycling performance. Second, to investigate if biochemical stress markers are affected over the treatment period. METHODS: Using a randomised, sham-controlled design, 18 active adults undertook seven consecutive days of IPC treatment (4×5 min occlusion/reperfusion) applied to each leg at either 220 mm Hg (treatment, n=9) or 20 mm Hg (sham, n=9). Urinary measures of inflammation, oxidative stress and indirect nitric oxide synthesis were undertaken daily. A simulated Keirin cycling competition (4×30 s Wingate tests) was performed on day 10, with baseline and postintervention cycling VO2max (days 1, 11 and 18) and 30 s Wingate tests (day 2) undertaken for comparison. RESULTS: The treatment group had enhanced mean cycling power (3.4%), while neopterin and biopterin in conjunction with total neopterin were significantly lower (p<0.05) and total biopterin significantly greater (p<0.05) during the simulated Keirin. Aerobic fitness measures significantly improved from baseline to postintervention (VO2peak: 12.8% ↑, maximal aerobic power: 18.5% ↑). CONCLUSIONS: Seven consecutive days of IPC improved aerobic and anaerobic capacity measures, with modulations in oxidative stress, immune system activation and nitric oxide/catecholamine synthesis.

High intensity interval training in a real world setting: a randomized controlled feasibility study in overweight inactive adults, measuring change in maximal oxygen uptake.

BACKGROUND: In research clinic settings, overweight adults undertaking HIIT (high intensity interval training) improve their fitness as effectively as those undertaking conventional walking programs but can do so within a shorter time spent exercising. We undertook a randomized controlled feasibility (pilot) study aimed at extending HIIT into a real world setting by recruiting overweight/obese, inactive adults into a group based activity program, held in a community park. METHODS: Participants were allocated into one of three groups. The two interventions, aerobic interval training and maximal volitional interval training, were compared with an active control group undertaking walking based exercise. Supervised group sessions (36 per intervention) were held outdoors. Cardiorespiratory fitness was measured using VO2max (maximal oxygen uptake, results expressed in ml/min/kg), before and after the 12 week interventions. RESULTS: On ITT (intention to treat) analyses, baseline (N = 49) and exit (N = 39) [Formula: see text]O2 was 25.3±4.5 and 25.3±3.9, respectively. Participant allocation and baseline/exit VO2max by group was as follows: Aerobic interval training N =  16, 24.2±4.8/25.6±4.8; maximal volitional interval training N = 16, 25.0±2.8/25.2±3.4; walking N = 17, 26.5±5.3/25.2±3.6. The post intervention change in VO2max was +1.01 in the aerobic interval training, -0.06 in the maximal volitional interval training and -1.03 in the walking subgroups. The aerobic interval training subgroup increased VO2max compared to walking (p = 0.03). The actual (observed, rather than prescribed) time spent exercising (minutes per week, ITT analysis) was 74 for aerobic interval training, 45 for maximal volitional interval training and 116 for walking (p =  0.001). On descriptive analysis, the walking subgroup had the fewest adverse events. CONCLUSIONS: In contrast to earlier studies, the improvement in cardiorespiratory fitness in a cohort of overweight/obese participants undertaking aerobic interval training in a real world setting was modest. The most likely reason for this finding relates to reduced adherence to the exercise program, when moving beyond the research clinic setting. TRIAL REGISTRATION: ACTR.org.au ACTRN12610000295044.

The effect of caffeine on maximal oxygen uptake and vertical jump performance in male basketball players.

This study investigated whether performance enhancement from caffeine described by other researchers transfers to male basketball players. The effects of caffeine ingestion were studied in a maximal-effort test on a treadmill that was followed by a vertical-jump test. Five elite-level male basketball players completed a graded treadmill test that measured maximal oxygen uptake, blood lactate profiles, respiratory exchange ratio, and rating of perceived exertion at each 3-minute stage. After a 15-minute warm-down, the subjects performed 10 vertical rebound jumps. Each subject completed the test twice--once with a 3 mg·kg(-1) of body weight dose of caffeine and once with a placebo, with the dosage administered 60 minutes before commencement of exercise. The test was thus administered according to a double-blind protocol. No substantial trends were found between caffeine and control trials, regardless of trial order. The study showed that the specified dosage had negligible effects on the players' power and endurance performance and had no efficacy as an ergogenic aid for male basketball players.

Determination of maximal oxygen uptake using the bruce or a novel athlete-led protocol in a mixed population.

Treadmill tests for maximal oxygen uptake (V̇O2max) have traditionally used set speed and incline increments regardless of participants training or exercise background. The aim of this study was to determine the validity of a novel athlete-led protocol for determining maximal aerobic fitness in adults. Twenty-nine participants (21 male, 8 female, age 29.8 ± 9.5 y, BMI 24.4 ± 3.1, mean ± SD) from a variety of exercise backgrounds were asked to complete two maximal treadmill running tests (using the standard Bruce or a novel athlete-led protocol [ALP]) to volitional failure in a counter-balanced randomised cross-over trial one week apart. We found no substantial difference in maximal oxygen uptake (47.0 ± 9.1 and 46.8 ± 10.7 ml·kg(-1)·min(-1), mean ± SD for the ALP and Bruce protocols respectively), evidenced by the Spearman correlation coefficient of 0.93 (90% confidence limits, 0.88-0.96). However, compared to the Bruce protocol, participants completing the ALP protocol attained a substantially higher maximal heart rate (ALP = 182.8 ± 10.5, Bruce = 179.7 ± 8.7 beats·min(-1)). Additionally, using the Bruce protocol took a longer period of time (23.2 ± 17.0 s) compared to the ALP protocol. It seems that using either treadmill protocol will give you similar maximal oxygen uptake results. We suggest the ALP protocol which is simpler, quicker and probably better at achieving maximal heart rates is a useful alternative to the traditional Bruce protocol.

Self-reported ability assessment in rock climbing.

Level of ability within rock climbing is generally expressed in terms of a "best ascent", rated using various grading systems within the sport. The most common method of obtaining this information is via self-report. The aim of this study was to examine the validity of self-reported climbing grades. Twenty-nine competitive rock climbers (17 males, 12 females) were first asked to report their current (defined as within the last 12 months) best on-sight lead ascent grade (Aus/NZ). The participants then climbed a specifically designed indoor route, under on-sight conditions (one attempt, no route practice or preview), to obtain an assessed grade. The route increased in difficulty, and was such that the distance achieved by the climber corresponded to a particular grade. The mean (±standard deviation) self-reported and assessed grade was 22.6 ± 3.4 and 22.0 ± 3.0 (Aus/NZ) respectively. Despite slight over- and underestimations in males and females respectively, there was no statistically significant difference between self-reported and assessed on-sight climbing grades. The results of this study suggest that self-reported climbing grades provide a valid and accurate reflection of climbing ability.

Effect of an on-sight lead on the physiological and psychological responses to rock climbing.

Rock climbing is a multi-discipline activity that encompasses forms such as bouldering, top roping and lead climbing on natural and artificial climbing surfaces. A major focus of research has been explanation of physiological functioning. More recent research indicates that anxiety levels are elevated for less experienced climbers and in response to lead climbing ascents. Research regarding the demands of rock climbing has placed a lesser focus on the interaction of psychological and physiological factors. The objective of this study was to examine the effects of an on-sight lead climb on the physiological and psychological demands of the climb in comparison with a subsequent lead climb. Ten intermediate level climbers volunteered to complete the two climbing trials, on-sight lead climb (OSLC) and second lead climb (LC2). Climb time, lactate concentrations (baseline, pre climb, post climb and 15 min post climb), heart rate (1 min pre climb, peak HR, 1 min post climb and average climb across the duration of the climb), oxygen consumption, pre climb anxiety (CSAI-2R) were assessed for each climber for both trials. Results indicated that there were significant differences in self reported pre climb somatic and cognitive anxiety (t(9) = 2.79, p = 0.01, t(9) = 1.94, p = 0.043), climb time (t(9) = 3.07, p = 0.0052) and post climb lactate concentrations between the climbs (t(9) = 2.58, p = 0.015). These results indicate that psychological as well as physiological stress impact upon the response to rock climbing. The higher anxiety levels associated with an OSLC are likely to have influenced the physiological responses for the intermediate climbers in this study. Future studies should take into account the type of climbing, experience of climbers and the number of ascents as well as taking into account the interaction between physiological and psychological factors in response to rock climbing. Key pointsFor intermediate climbers, there are significant differences in physiological and psychological responses to on-sight lead and subsequent lead climb.There was an increased psychological and physiological load for leading a climb for the first time (on-sight).These results indicate that the type of climbing should be taken into account when interpreting results from climbing studies with intermediate or recreational climbers.