Exergaming for physical activity: A systematic review.

OBJECTIVE: This review evaluates current literature on intensity selection, perceptual responses, activity enjoyment and adherence rates of exergaming. METHODS: The literature search identified manuscripts that investigated exercise intensity, perceptual responses, or exercise adherence of exergaming in young adults. RESULTS: Based on results of 29 studies, the current review suggest some exergaming activities have the potential to elicit moderate to vigorous exercise intensity and could potentially be substituted for traditional exercise. Additionally, exergame activities may aid in the start of exercise adherence by lowering the individual's perceived exertion when playing exergames. Exergaming not only has the potential to enhance enjoyment through an exercise objective but also through the distracting nature of video games. CONCLUSIONS: Exergaming shows potential to be substituted for traditional exercise and could offer a new, varied form of exercise for sedentary individuals. Future research should examine the influence of exergaming experience on intensity selection and adherence rates.

Caffeine influences cadence at lower but not higher intensity RPE-regulated cycling.

Caffeine blunts RPE estimations but effects on selected cycling cadence are unclear. PURPOSE: This study examined influence of caffeine on cycling cadence with intensities prescribed at RPE 4 and 7 (OMNI Scale). METHODS: College-aged (20.5±2.0y) male and female volunteers (n=15) (VO2 peak=40.3±4.0,) completed a maximal cycling test followed by trials where they adjusted cadence (CAD) (clamped resistances) to produce overall feelings equivalent to RPE 4 (RPE4) and RPE 7 (RPE7) (10min each) following caffeine (CAF) (6mg·kg-1·min-1) and placebo (PLA) (counterbalanced) ingestion. Participants were blinded to cadence during production trials. RESULTS: Repeated measures ANOVA showed a significant main effect (trial) for CAD (CAF ~4rev·min-1 faster) for RPE4 but no significance for RPE7. Main effect for heart rate (HR) was not significant for RPE4 but significant for RPE7 (CAF ~4b·min-1 higher). Main effects showed mean VO2 significantly higher (~1.5-2ml·kg-1·min-1) for CAF for RPE4 and RPE7. Using a calculated least significant difference (5rev·min-1) positive responses were observed for five individuals (33%) for RPE4 and 3 individuals (20%) for RPE7. No negative (significantly slower cadences) responses were observed. RER in select trials suggested increased reliance on free fatty acid for CAF in responders. CONCLUSIONS: Mean results show a mild effect of CAF on cadence selection during RPE production. However, assessing individual results more effectively clarifies ergogenic responses. Future research should identify factors responsible for diverse responses to caffeine during exercise.

Influence of Dehydration on Intermittent Sprint Performance.

This study examined the effects of dehydration on intermittent sprint performance and perceptual responses. Eight male collegiate baseball players completed intermittent sprints either dehydrated (DEHY) by 3% body mass or euhydrated (EU). Body mass was reduced through exercise in the heat with controlled fluid restriction occurring 1 day before the trial. Participants completed twenty-four 30-m sprints divided into 3 bouts of 8 sprints with 45 seconds of rest between each sprint and 3 minutes between each bout. Perceived recovery status (PRS) scale was recorded before the start of each trial. Heart rate (HR), ratings of perceived exertion (RPE) (0-10 OMNI scale), and perceived readiness (PR) scale were recorded after every sprint, and session RPE (SRPE) was recorded 20 minutes after completing the entire session. A 2 (condition) × 3 (bout of sprints) repeated-measures ANOVA revealed a significant main effect of condition on mean sprint time (p = 0.03), HR (p < 0.01), RPE (p = 0.01), and PR (p = 0.02). Post hoc tests showed significantly faster mean sprint times for EU vs. DEHY during the second (4.87 ± 0.29 vs. 5.03 ± 0.33 seconds; p = 0.01) and third bouts of sprints (4.91 ± 0.29 vs. 5.12 ± 0.44 seconds; p = 0.02). Heart rate was also significantly lower (p ≤ 0.05) for EU during the second and third bouts. Post hoc measures also showed significantly impaired (p ≤ 0.05) feelings of recovery (PRS) before exercise and increased (p ≤ 0.05) perceptual strain before each bout (PR) during the second and third bouts of repeated sprint work (i.e., RPE and PR) and after the total session (SRPE) in the DEHY condition. Dehydration impaired sprint performance, negatively altered perception of recovery status before exercise, and increased RPE and HR response.

Wheelchair-mounted accelerometers for measurement of physical activity.

PURPOSE: To evaluate the validity of a wheelchair frame-mounted accelerometer for the assessment of physical activity of wheelchair users. METHOD: Twelve collegiate wheelchair basketball players participated in this study. The study was conducted in a modern indoor gymnasium at a university in the USA. A randomized, crossover experimental design was used to investigate accelerometer output, participant heart rate, and distance travelled. Participants performed two trials of wheeling at a combination of two different effort levels (light and moderate: Prescribed using perceived exertion) and two different modes (continuous and stop-go). RESULTS: Accelerometer vector magnitude activity counts (VM), heart rate (HR), and distance travelled were significantly different between light and moderate effort (p < 0.01). The continuous and stop-go wheeling modes were not significantly different (p = 0.37) for VM, but were significantly different (p < 0.01) for both HR and distance. Between-trial reliability of all data collapsed for the effort and mode combinations were: VM: r = 0.85; HR: r = 0.86; and distance: r = 0.96. CONCLUSION: A wheelchair frame-mounted accelerometer differentiated between perceptually-prescribed low and moderate effort levels and may prove to be a valid instrument in the detection of a wheelchair users' physical activity. [Box: see text].

A practical approach to monitoring recovery: development of a perceived recovery status scale.

The aim of this study was to develop and test the practical utility of a perceived recovery status (PRS) scale. Sixteen volunteers (8 men, 8 women) performed 4 bouts of high-intensity intermittent sprint exercise. After completion of the baseline trial, in a repeated-measures design, subjects were given variable counterbalanced recovery periods of 24, 48, and 72 hours whereupon they repeated an identical intermittent exercise protocol. After a warm-up period, but before beginning each subsequent bout of intermittent sprinting, each individual provided their perceived level of recovery with a newly developed PRS scale. Similar to perceived exertion during exercise, PRS was based on subjective feelings. The utility of the PRS scale was assessed by measuring the level of agreement of an individual's perceived recovery relative to their performance during the exercise bout. Perceived recovery status and change (both positive and negative) in sprint performance during multiple bouts of repeated sprint exercise were moderately negative correlated (r = -0.63). Additionally, subjects were able to accurately assess level of recovery using the PRS scale indicated by correspondence with negative and positive changes in total sprint time relative to their previous session. The ability to detect changes in performance using a noninvasive psychobiological tool to identify differences in performance was independent of other psychological and physiological markers measured during testing, because there were no differences (p > 0.05) among ratings of perceived exertion (RPE), heart rate, blood lactate concentration, or session RPE values among any of the performance trials. Although further study is needed, current results indicate a subjective approach may be an effective means for assessing recovery from day to day, at least under similar conditions.

Caffeine and anaerobic performance: ergogenic value and mechanisms of action.

The effect caffeine elicits on endurance performance is well founded. However, comparatively less research has been conducted on the ergogenic potential of anaerobic performance. Some studies showing no effect of caffeine on performance used untrained subjects and designs often not conducive to observing an ergogenic effect. Recent studies incorporating trained subjects and paradigms specific to intermittent sports activity support the notion that caffeine is ergogenic to an extent with anaerobic exercise. Caffeine seems highly ergogenic for speed endurance exercise ranging in duration from 60 to 180 seconds. However, other traditional models examining power output (i.e. 30-second Wingate test) have shown minimal effect of caffeine on performance. Conversely, studies employing sport-specific methodologies (i.e. hockey, rugby, soccer) with shorter duration (i.e. 4-6 seconds) show caffeine to be ergogenic during high-intensity intermittent exercise. Recent studies show caffeine affects isometric maximal force and offers introductory evidence for enhanced muscle endurance for lower body musculature. However, isokinetic peak torque, one-repetition maximum and muscular endurance for upper body musculature are less clear. Since relatively few studies exist with resistance training, a definite conclusion cannot be reached on the extent caffeine affects performance. It was previously thought that caffeine mechanisms were associated with adrenaline (epinephrine)-induced enhanced free-fatty acid oxidation and consequent glycogen sparing, which is the leading hypothesis for the ergogenic effect. It would seem unlikely that the proposed theory would result in improved anaerobic performance, since exercise is dominated by oxygen-independent metabolic pathways. Other mechanisms for caffeine have been suggested, such as enhanced calcium mobilization and phosphodiesterase inhibition. However, a normal physiological dose of caffeine in vivo does not indicate this mechanism plays a large role. Additionally, enhanced Na+/K+ pump activity has been proposed to potentially enhance excitation contraction coupling with caffeine. A more favourable hypothesis seems to be that caffeine stimulates the CNS. Caffeine acts antagonistically on adenosine receptors, thereby inhibiting the negative effects adenosine induces on neurotransmission, arousal and pain perception. The hypoalgesic effects of caffeine have resulted in dampened pain perception and blunted perceived exertion during exercise. This could potentially have favourable effects on negating decreased firing rates of motor units and possibly produce a more sustainable and forceful muscle contraction. The exact mechanisms behind caffeine's action remain to be elucidated.

Acute heart rate, blood pressure, and RPE responses during super slow vs. traditional machine resistance training protocols using small muscle group exercises.

Acute cardiovascular and perceptual responses to Super Slow resistance training (SS) are not well understood. This study compared blood pressure (BP), heart rate (HR), and ratings of perceived exertion (RPE) between SS and traditional machine (TM) protocols. Participants (n = 20) completed three sessions of elbow flexion (EF) and knee extension (KE). Session 1 consisted of determining 1RM for EF and KE and a familiarization trial for the SS technique. Sessions 2 and 3 were counterbalanced, with subjects completing three sets of SS (10 seconds concentric, 5 seconds eccentric per rep, 40% 1RM) and TM (2 seconds concentric, 4 seconds eccentric per rep, 65% 1RM). Paramount resistance training equipment was used for both exercises. Peak HR was recorded for each set, with recovery HR taken between sets after 3 minutes of rest. Blood pressure was taken after 5 minutes of seated rest, after each set, before sets 2 and 3, and at 2 minutes post set 3. Ratings of perceived exertion for active musculature were obtained three times per set. Although systolic BP (SBP) and diastolic BP (DBP) responses were not significantly different between SS and TM for EF or KE, SBP (SS and TM combined) was significantly lower during EF and was significantly higher during KE than resting BP. Diastolic BP (SS and TM combined) was not significantly different from resting BP for EF or KE. Peak HR was significantly greater during TM (vs. SS) for EF and KE. Ratings of perceived exertion were also significantly greater during TM for EF and KE. Even though SBP was greater for SS and TM combined during KE, comparing SS and TM revealed minimal differences in BP. This suggests that, when performing small muscle group exercises with lighter weight at a slow speed, either SS or TM would be appropriate for individuals to whom strength training is not contraindicated.

Multiple Models Can Concurrently Explain Fatigue During Human Performance.

One of the most commonly and thoroughly studied paradigms of human performance is fatigue. However, despite volumes of research there remains considerable controversy among scientists regarding definitive conclusions about the specific mechanism(s) contributing to fatigue. Within the literature there are three primary yet distinctly different governing ideas of fatigue; the traditionally referenced central model and peripheral model as well as the emerging central governor model (CGM). The CGM has recently been advocated by a limited number of researchers and is suggestive of a more integrative model of fatigue when compared the traditional peripheral and central models. However, more work is needed to determine the specific and perhaps synergistic roles of each paradigm during exercise or sport activity. This article contains three components; (1) a brief overview of the problems associated with defining fatigue, (2) a description of the models governing interpretation of fatigue and, (3) a presentation of multiple interpretations of selected data to demonstrate that some results can be reasonably explained using multiple models of fatigue, often concurrently. The purposes of this paper are to reveal that a) perhaps it is not the results that suggest a certain paradigm of regulation, yet that it may be a product of an a priori definition that is being employed and b) an integrative model of central and peripheral fatigue may present a plausible explanation for fatigue vs. adherence to the notion that each paradigm is mutually exclusive.

Effects of caffeine and aspirin on light resistance training performance, perceived exertion, and pain perception.

This study compared independent effects of caffeine and aspirin on muscular endurance (repetitions), heart rate (HR), perceived exertion (RPE), and perceived pain index (PPI) during light resistance training bouts performed to volitional failure. It was hypothesized that the hypoalgesic properties of these ergogenic aids would decrease pain perception and potentially result in enhanced performance. College-aged men (n = 15) participated in a within-subjects, double-blind study with three independent, counterbalanced sessions wherein aspirin (10 mg x kg(-1)), caffeine (6 mg x kg(-1)), or matched placebo were ingested 1 hour before exercise, and RPE, HR, PPI, and repetitions (per set and total per exercise) were recorded at 100% of individual, predetermined, 12-repetition maximum for leg extensions (LE) and seated arm curls (AC). Repeated-measures analyses of variance were used for between-trial comparisons. Caffeine resulted in significantly greater (p < 0.05) HR (LE and AC), total repetitions (LE), and repetitions in set 1 (LE and AC) compared with aspirin and placebo. Aspirin resulted in significantly higher PPI in set 1 (LE). In LE, 47% of participants' performance exceeded the predetermined effect size (>or= 5 repetitions) for total repetitions, with 53% exceeding the effect size (>or= 2 repetitions) for repetitions in set 1 with caffeine (vs. placebo). In AC, 53% (total repetitions) and 47% (set 1 repetitions) of participants exceeded effect sizes with caffeine (vs. placebo), with only 13% experiencing decrements in performance (total repetitions). Aspirin also produced a higher PPI and RPE overall and in set 1 (vs. placebo). This study demonstrates that caffeine significantly enhanced resistance training performance in LE and AC, whereas aspirin did not. Athletes may improve their resistance training performance by acute ingestion of caffeine. As with most ergogenic aids, our analyses indicate that individual responses vary greatly.

Session RPE following interval and constant-resistance cycling in hot and cool environments.

PURPOSE: This study examined effects of heat gain, circulatory adjustment to temperature regulation (HR), and [La] consequent to interval (INT) and constant-load (CON) cycling on session RPE (S-RPE). METHODS: Male volunteers (N = 10) completed a cycle ergometer VO2peak test and then, in a randomized, counterbalanced order, four cycling bouts, including constant load (approximately 45% VO2peak) (CON) and interval (8 x 1 min at about 90% VO2peak, 1 min between intervals) (INT), in hot (approximately 32.5 WBGT) (HOT) and cool (approximately 21.0 WBGT) (COOL) environments. Trials included a standardized warm-up and cool-down (10 min each: 0 W, 60 rpm). Total external work was equated among all trials, with blood lactate ([La]), heart rate (HR), rectal temperature (Tre), and acute RPE recorded at 10, 13, 17, 21, 25, and 36 min. S-RPE was recorded 20 min after each session. RESULTS: HOT (CON and INT) resulted in significantly (P < 0.05) greater heat gain (Tre), HR, and RPE-O, whereas INT had significantly elevated [La] versus CON (HOT and COOL). HOT yielded significantly higher S-RPE versus COOL for CON (HOT = 5.6 +/- 2.1, COOL = 4.3 +/- 1.3) and INT (HOT = 7.0 +/- 1.9, COOL = 5.1 +/- 2.0). S-RPE was significantly higher for INT/HOT than CON/HOT. CONCLUSIONS: Heat gain and cardiac strain (Tre, HR) and [La]) were manipulated with environment and exercise type while holding total work constant. The added strain of HOT was reflected in elevated S-RPE for both CON and INT. S-RPE linkage with [La] was limited to HOT trials, indicating only a loose association. These data indicate that under the conditions of this study, S-RPE is similar to acute RPE in that no single mediator seems universally dominant.

Cross-validation of the 20- versus 30-s Wingate anaerobic test.

The 30-s Wingate anaerobic test (30-WAT) is the most widely accepted protocol for measuring anaerobic response, despite documented physical side effects. Abbreviation of the 30-WAT without loss of data could enhance subject compliance while maintaining test applicability. The intent of this study was to quantify the validity of the 20-s Wingate anaerobic test (20-WAT) versus the traditional 30-WAT. Fifty males (mean +/- SEM; age = 20.5 +/- 0.3 years; Ht = 1.6 +/- 0.01 m; Wt = 75.5 +/- 2.6 kg) were randomly selected to either a validation (N = 35) or cross-validation group (N = 15) and completed a 20-WAT and 30-WAT in double blind, random order on separate days to determine peak power (PP; W kg(-1)), mean power (MP; W kg(-1)), and fatigue index (FI; %). Utilizing power outputs (relative to body mass) recorded during each second of both protocols, a non-linear regression equation (Y (20WAT+10 )= 31.4697 e(-0.5)[ln(X (second)/1174.3961)/2.6369(2)]; r (2) = 0.97; SEE = 0.56 W kg(-1)) successfully predicted (error approximately 10%) the final 10 s of power outputs in the cross-validation population. There were no significant differences between MP and FI between the 20-WAT that included the predicted 10 s of power outputs (20-WAT+10) and the 30-WAT. When derived data were subjected to Bland-Altman analyses, the majority of plots (93%) fell within the limits of agreement (+/-2SD). Therefore, when compared to the 30-WAT, the 20-WAT may be considered a valid alternative when used with the predictive non-linear regression equation to derive the final power output values.

Effects of caffeine on repetitions to failure and ratings of perceived exertion during resistance training.

CONTEXT: Ergogenic effects of caffeine on aerobic or endurance exercise are well documented. Conversely, the ergogenic value of caffeine on high-intensity, primarily anaerobic performance is not well understood even though the proposed mechanisms of action for caffeine permit a strong theoretical basis for application to this type of exercise. PURPOSE: This study examined effects of caffeine (Ca) on number repetitions (reps), ratings of perceived exertion (RPE), and peak heart rate (PHR) during resistance-training exercise with reps performed to volitional failure. METHODS: Subjects (N = 17) were tested for 10-rep maximum in bench press (BP) and leg press (LP). In sessions 2 and 3, Ca (approximately 6 mg/kg) or placebo (Pl) was ingested 1 hr beforehand in a double-blind manner and counterbalanced order. Subjects performed 3 sets to failure (BP and LP) with reps, PHR, and RPE recorded each set. Repeated-measures ANOVAs, 2 (trial) x 3 (set), were used to analyze dependent measures with the Tukey honestly significant difference used when necessary as the post hoc test. RESULTS: In BP, no significant differences (Ca vs Pl) were observed (reps, RPE, PHR). During set 3 of LP training, Ca was associated with significantly higher reps (12.5 +/- 4.2 vs 9.9 +/- 2.6) and PHR (158.5 +/- 11.9 vs 151.8 +/- 13.2). No significant RPE differences were found during LP. CONCLUSIONS: The findings of similar RPE concurrent with higher reps suggest that caffeine can blunt pain responses, possibly delaying fatigue in high-intensity resistance training. Ergogenic effects might be limited to the later sets in a resistance-training session. Further research is warranted regarding ergogenic effects of caffeine during resistance training and potential mechanisms of action.

Validation of the Adult OMNI Scale of perceived exertion for walking/running exercise.

PURPOSE: Concurrent and construct validity of the OMNI-Walk/Run Scale of Perceived Exertion was examined using young adult women and men (18-36 yr). METHODS: Concurrent validity was established by correlating OMNI-Walk/Run Scale ratings of perceived exertion (RPE-OMNI) with oxygen uptake (VO2), relative maximal oxygen uptake (%VO2(max)), ventilation (VE), respiratory rate (RR), respiratory exchange ratio (RER), and heart rate (HR) to a graded exercise test on a treadmill. Construct validity was established by correlating RPE-OMNI with RPE from the Borg (6-20) Scale (RPE-BORG). Measurements were made every min throughout the test. RESULTS: The range of exercise responses across the incremental walking/running test for the female and male groups were: VO2 = 0.99-3.9 L x min(-1), HR = 98-190 beats x min(-1) and RPE-OMNI = 1.3-9.4. Correlation/regression analyses indicated that RPE-OMNI distributed as a positive linear function for all criterion measures; r = 0.67 to 0.88 (P < 0.05). RPE-OMNI was positively and linearly related to the RPE-BORG; r = 0.96 (P < 0.01) for both the female and male groups. CONCLUSIONS: Concurrent and construct evidence supports use of the OMNI-Walk/Run Scale by adult women and men to estimate RPE during graded exercise test on a treadmill.

A comparison of respiratory compensation thresholds of anaerobic competitors, aerobic competitors and untrained subjects.

This study compared respiratory compensation thresholds (RCT) ( VCO(2) inflection point) of competitors in highly aerobic events (aerobic competitors, ARC) ( n=16), competitors in highly anaerobic events (anaerobic competitors, ANC) ( n=15), and untrained subjects (UT) ( n=25). Maximal oxygen consumption ( VO(2max)), respiratory compensation threshold as a percentage of VO(2max) (RCT), and VO(2) at RCT ( Vdot;O(2RCT)) were determined during a maximal Bruce treadmill protocol. VO(2max) (ml x kg(-1) min(-1)) was significantly greater ( P<0.05) for ARC [67.2 (8.5)] than for ANC [50.0 (7.8)] and UT [43.8 (5.4)]. However, the difference between ANC and UT only approached significance ( P=0.07). RCT was not significantly different between ARC [76.3 (8.7)] and ANC [80.7 (6.8)] but was significantly lower ( P<0.05) for UT [62.5 (8.8)]. VO(2RCT) (ml x kg(-1) min(-1)) was significantly greater ( P<0.05) for ARC [51.6 (11.0)] and ANC [40.2 (6.6)] than for UT [27.4 (5.4)], with a significant difference also between ARC and ANC. While used as a criterion for group assignment, greater VO(2max), as well as RCT values in ARC (vs UT), reflect chronic aerobic training adaptations. ANC demonstrated VO(2max) values intermediate to ARC and UT, with RCT very comparable to those found in ARC. The results suggest subjects competitive in highly anaerobic events do not possess excessively high VO(2max) values. These individuals, however, demonstrate a high RCT when values are expressed relative to VO(2max). Oxygen consumption at the RCT in this group is superior to that in UT but inferior to that in ARC, which likely has important implications regarding performance.