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High intensity interval training (HIIT) has become an increasingly popular form of exercise due to its potentially large effects on exercise capacity and small time requirement. This study compared the effects of two HIIT protocols vs steady-state training on aerobic and anaerobic capacity following 8-weeks of training. Fifty-five untrained college-aged subjects were randomly assigned to three training groups (3x weekly). Steady-state (n = 19) exercised (cycle ergometer) 20 minutes at 90% of ventilatory threshold (VT). Tabata (n = 21) completed eight intervals of 20s at 170% VO2max/10s rest. Meyer (n = 15) completed 13 sets of 30s (20 min) @ 100% PVO2 max/ 60s recovery, average PO = 90% VT. Each subject did 24 training sessions during 8 weeks.There were significant (p0.05) increases in VO2max (+19, +18 and +18%) and PPO (+17, +24 and +14%) for each training group, as well as significant increases in peak (+8, + 9 and +5%)mean (+4, +7 and +6%) power during Wingate testing, but no significant differences between groups. Measures of the enjoyment of the training program indicated that the Tabata protocol was significantly less enjoyable (p0.05) than the steady state and Meyer protocols, and that the enjoyment of all protocols declined (p0.05) across the duration of the study. The results suggest that although HIIT protocols are time efficient, they are not superior to conventional exercise training in sedentary young adults. Key pointsSteady state training equivalent to HIIT in untrained studentsMild interval training presents very similar physiologic challenge compared to steady state trainingHIIT (particularly very high intensity variants were less enjoyable than steady state or mild interval trainingEnjoyment of training decreases across the course of an 8 week experimental training program.

This study aimed to investigate whether ventilatory (VT) and respiratory compensation (RCT) thresholds could be derived from percentages of maximal running speed (Vmax). During the model building phase (1), VTRCT of 31 competitive level athletes were identified with respiratory gas exchange. During the cross-validation phase (2), 20 subjects performed a treadmill test to identify Vmax and then they performed 30-min runs at velocities 2SE below or above the velocity at VT and RCT derived from (1), with measurement of blood lactate [BL], RPE, heart rate (HR), and speech comfort. Phase (1) revealed that VT and RCT were reached at 67 ± 9% and 84 ± 6% of Vmax. In (2) sustained running 2SE below VT (64% Vmax) was associated with the ability to finish 30-min, with low and constant [BL] (~2.5 mmol.l(-1)), moderate RPE (~3.0-3.5), a small HR drift, and ability to speak comfortably. Conversely, running at 2SE above RCT (86% Vmax) was associated with the inability to finish 30-min (18.5 ± 2.5 min to fatigue), increasing [BL] (end-exercise = 11.9 ± 0.9 mmol.l(-1)), high RPE (end-exercise = 8.9 ± 1.0), large HR drift (end-exercise = 98 ± 3% HRmax), and inability to speak comfortably. Simple percentages of Vmax (≤64% and ≥86%) obtained from a treadmill test without gas exchange, may be useful for prescribing exercise training intensities. Key pointsSimple performance parameters can be used to provide indications of physiologic thresholds.64% and 86% of the maximal running speed produce conditions consistent with ≤VT and ≥RCT.The combination of technology free feedback techniques such as the Talk Test and RPE and the simple %Vmax can be used as available and easy methods for the performance evaluation.Training prescription can be better addressed to the improvement of the aerobic or anaerobic capacity.

The purpose of this study was to compare session rating of perceived exertion for different resistance training techniques in the squat exercise. These techniques included traditional resistance training, super slow, and maximal power training. Fourteen college-age women (Mean ± SD; age = 22 ± 3 years; height = 1.68 ± 0. 07 m) completed three experimental trials in a randomized crossover design. The traditional resistance training protocol consisted of 6 sets of 6 repetitions of squats using 80% of 1-RM. The super slow protocol consisted of 6 sets of 6 repetitions using 55% of 1-RM. The maximal power protocol consisted of 6 sets of 6 repetitions using 30% of 1-RM. Rating of perceived exertion (RPE) measures were obtained following each set using Borg's CR-10 scale. In addition, a session RPE value was obtained 30 minutes following each exercise session. When comparing average RPE and session RPE, no significant difference was found. However, power training had significantly lower (p0.05) average and session RPE (4.50 ± 1.9 and 4.5 ± 2.1) compared to both super slow training (7.81 ± 1.75 and 7.43 ± 1.73) and traditional training (7.33 ± 1.52 and 7.13 ± 1.73). The results indicate that session RPE values are not significantly different from the more traditional methods of measuring RPE during exercise bouts. It does appear that the resistance training mode that is used results in differences in perceived exertion that does not relate directly to the loading that is used. Using session RPE provides practitioners with the same information about perceived exertion as the traditional RPE measures. Taking a single measure following a training session would appear to be much easier than using multiple measures of RPE throughout a resistance training workout. However, practitioners should also be aware that the RPE does not directly relate to the relative intensity used and appears to be dependent on the mode of resistance exercise that is used. Key PointsThe present study showed that session RPE values are not significantly different from the more traditional methods of measuring RPE during exercise bouts.Power training had significantly lower average and session RPE compared to both super slow training and traditional trainingIt does appear that the resistance training mode that is used results in differences in perceived exertion that does not relate directly to the loading that is used.

The purpose of this study was to monitor the stress-induced alteration in concentrations of salivary immunoglobulin (S-IgA) and cortisol and the incidence of upper respiratory tract infections (URTI) over the course of a 9-week competitive season in college student-athletes and college students. The subjects consisted of 14 NCAA Division III collegiate female soccer athletes (19.8 ± 1.0 years, mean ± SD) and 14 female college students (22.5 ± 2.6 years). Salivary samples were collected for 9 weeks during a competitive soccer season. S-IgA and cortisol concentrations were determined by enzyme linked immunosorbent assay (ELISA). A training and performance questionnaire was given to the subjects every week, to record the subjects' session rating of perceived exertion (RPE) for all the training, load, monotony and strain, as well as any injuries or illnesses experienced. The between groups ANOVA procedure for repeated measures showed no changes in salivary concentrations of IgA and cortisol. Chi-square analysis showed that during the 9-week training season injury and illness occurred at a higher rate among the soccer players. There was a significant difference at baseline between soccer and control S-IgA levels (p≤0.05). Decreased levels of S-IgA and increases in the indices of training (load, strain and monotony) were associated with an increase in the incidence of illness during the 9-week competitive soccer season. Key PointsThere was a significant difference at baseline between soccer and control S-IgA levelsEighty-two percent of illnesses could be explained by a preceding decrease in S-IgA.Increases in the indices of training (load, strain and monotony) were associated with an increase in the incidence of illness.

The purpose of this study was to measure the salivary cortisol response to different intensities of resistance exercise. In addition, we wanted to determine the reliability of the session rating of perceived exertion (RPE) scale to monitor resistance exercise intensity. Subjects (8 men, 9 women) completed 2 trials of acute resistance training bouts in a counterbalanced design. The high intensity resistance exercise protocol consisted of six, ten-repetition sets using 75% of one repetition maximum (RM) on a Smith machine squat and bench press exercise (12 sets total). The low intensity resistance exercise protocol consisted of three, ten-repetition sets at 30% of 1RM of the same exercises as the high intensity protocol. Both exercise bouts were performed with 2 minutes of rest between each exercise and sessions were repeated to test reliability of the measures. The order of the exercise bouts was randomized with least 72 hours between each session. Saliva samples were obtained immediately before, immediately after and 30 mins following each resistance exercise bout. RPE measures were obtained using Borg's CR-10 scale following each set. Also, the session RPE for the entire exercise session was obtained 30 minutes following completion of the session. There was a significant 97% increase in the level of salivary cortisol immediately following the high intensity exercise session (P0.05). There was also a significant difference in salivary cortisol of 145% between the low intensity and high intensity exercise session immediately post-exercise (P0.05). The low intensity exercise did not result in any significant changes in cortisol levels. There was also a significant difference between the session RPE values for the different intensity levels (high intensity 7.1 vs. low intensity 1.9) (P0.05). The intraclass correlation coefficient for the session RPE measure was 0.95. It was concluded that the session RPE method is a valid and reliable method of quantifying resistance exercise and that salivary cortisol responds promptly to the exercise load. Key PointsThe present study showed that salivary cortisol responses were significantly different immediately post exercise between the low intensity and high intensity exercise sessionsSalivary measures of cortisol can be used to delineate between high and low intensity resistance exercise bouts.The session RPE method appears to be a reliable method of quantifying resistance exercise.