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Hernandez, DJ, Healy, S, Giacomini, ML, and Kwon, YS. Effect of rest interval duration on the volume completed during a high-intensity bench press exercise. J Strength Cond Res XX(X): 000-000, 2020-Between-set rest intervals (RIs) are one of the most important variables in resistance training; however, no known research has investigated the effects of RIs greater than 5 minutes during high-intensity strength training. The purpose of this research was to examine the effects of 3 different RIs on repetition sustainability and training volume (sets × reps × resistance) during a high-intensity bench press exercise. Fifteen resistance-trained male subjects (mean ± SD, age = 25.5 ± 4.5 years, and bench press 1 repetition maximum [1RM] ratio [1RM/body mass] = 1.39 ± 0.1) completed 3 experimental sessions, during which 4 sets of the bench press were performed with 85% of 1RM load. Subjects performed the bench press using 3 different RIs in a random counterbalanced design. Data were analyzed using both a one- and two-way analysis of variance with repeated measures. As sets progressed, repetitions were significantly different (p < 0.05) between all RIs, and only the 8-minute RI (p < 0.05) allowed for the complete sustainability of repetitions over 4 consecutive sets. Subjects attained the greatest training volume (p < 0.05) using an 8-minute RI between sets compared with a 2- or 5-minute RI. Similarly, a significantly greater training volume was achieved using the 5-minute RI compared with the 2-minute RI. Resistance-trained men, with the goal of greater volume during strength training, would benefit from longer RIs, specifically using an 8-minute RI between 4 consecutive sets of a bench press exercise.

Alicea, SK, Parrott, AD, Manos, TM, and Kwon, YS. Comparison of the affective responses to continuous training and high-intensity interval training protocols: application of the dual-mode model. J Strength Cond Res XX(X): 000-000, 2020-High-intensity interval training (HIIT) is time-efficient and has physiological benefits similar to or greater than that of continuous training (CT); however, there are mixed results regarding how HIIT protocols influence affect. The purpose of this study was to compare acute affective responses between HIIT and CT protocols over time using the Dual-Mode Model (DMM) as a theoretical framework. Subjects included 12 healthy women (aged 19-28 years) who completed a HIIT protocol consisting of a 2-minute work interval (100% V[Combining Dot Above]O2max) followed by a 2-minute rest interval (∼55% V[Combining Dot Above]O2max), and a CT protocol set at the workrate corresponding to their respiratory compensation point (RCP; ∼80% V[Combining Dot Above]O2max). Protocols were matched for average intensity, total duration, and energy expenditure. After blood pressure, anthropometrics, body composition, and V[Combining Dot Above]O2max measurements were taken, responses were recorded for affect (Feeling Scale [FS]), arousal (Felt Arousal Scale [FAS]), and rate of perceived exertion (RPE) before each protocol, during the last 10 seconds of every 2 minutes during the protocol, and at time points 2, 5, and 10 minutes after the protocol. Heart rate was also monitored continuously, and exercise enjoyment was measured before and after exercise. A repeated-measures analysis of variance revealed no significant differences in affect between CT (M = 2.5, SD = 2.1) and HIIT (M = 2.6, SD = 2.1) protocols over the duration of the exercise. There were no significant differences in mean RPE between CT (M = 12.9, SD = 2.7) and HIIT (M = 13.0, SD = 1.9) protocols (t = 0.333, p = 0.745) or in enjoyment between CT (M = 2.3, SD = 1.1) and HIIT (M = 2.0, SD = 0.9) protocols (t = -0.288, p = 0.492). In addition, based on visual inspection, the general patterning of the mean FS and FAS values between HIIT and CT was similar within the circumplex model, supporting the DMM. In conclusion, a HIIT protocol at V[Combining Dot Above]O2max and 1:1 exercise:rest interval did not result in a different affect response, perceived exertion, or enjoyment level when compared with a CT protocol at RCP.

We previously reported that cold application to the palms between sets of high-intensity bench press exercise produces an ergogenic effect in men. In this study, we hypothesized that palm cooling (PC) or heating during rest intervals between high-intensity weight training sets will increase total repetitions and exercise volume load (kilograms) in resistance trained female subjects in a thermoneutral (TN) environment. Eight female subjects (mean ± SD, age = 25 ± 6 years, height = 160 ± 6 cm, body mass = 56 ± 7 kg, 1-repetition maximum [1RM] = 52 ± 6 kg, weight training experience = 6 ± 2 years) completed 4 sets of 85% 1RM bench press exercise to failure, with 3-minute rest intervals. Exercise trials were performed in a counterbalanced order on 3 days, separated by at least 3 days in TN, Palm heating (PH), and PC conditions. Heating and cooling were applied by placing both hands in a hand cooling device with the hand plate set to 45° C for heating and 10° C for cooling. Data were analyzed using a 2-factor repeated-measures analysis of variance and Tukey's post hoc tests. Palm cooling repetitions were significantly higher than TN repetitions during the second set, and PH repetitions were significantly higher than those of TN during the fourth set. Total exercise volume load (kilograms) for both PC (1,387 ± 358) and PH (1,349 ± 267) were significantly higher than TN (1,187 ± 262). In women, both heating and cooling of the palms between sets of resistance exercise increased the total exercise volume load performed. This ergogenic response to a peripheral sensory input is consistent with the central governor theory of muscular fatigue.

The widespread belief that local cooling impairs short-term, strenuous exercise performance is controversial. Eighteen original investigations involving cooling before and intermittent cooling during short-term, intensive exercise are summarized in this review. Previous literature examining short-term intensive exercise and local cooling primarily has been limited to the effects on muscle performance immediately or within minutes following cold application. Most previous cooling studies used equal and longer than 10 minutes of pre-cooling, and found that cooling reduced strength, performance and endurance. Because short duration, high intensity exercise requires adequate warm-up to prepare for optimal performance, prolonged pre-cooling is not an effective method to prepare for this type of exercise. The literature related to the effect of acute local cooling immediately before short duration, high intensity isotonic exercise such as weight lifting is limited. However, local intermittent cooling during short-term, high intense exercise may provide possible beneficial effects; first, by pain reduction, caused by an "irritation effect" from hand thermal receptors which block pain sensation, or second, by a cooling effect, whereby stimulation of hand thermal receptors or a slight lowering of blood temperature might alter central fatigue.