A hard/heavy intensity is too much: The physiological, affective, and motivational effects (immediately and 6 months post-training) of unsupervised perceptually regulated training

Effect of High-Intensity Interval, Moderate-Intensity Continuous, and Self-Selected Intensity Training on Health and Affective Responses

Purpose: To compare the effects of 12-week high-intensity interval (HIIT), moderate-intensity continuous (MICT), and self-selected intensity training (SSIT) on health outcomes and affective responses. Methods: Seventy-three overweight/obese inactive adults (62% woman; age, 31.4 ± 7.2 years; height, 1.66 ± 0.09 cm; Body mass index, 28.9 ± 2.7 kg.m-2) who were randomized into HIIT (n = 23), MICT (n = 24) and SSIT (n = 26) groups. The training was conducted three times per week in an outdoor environment, with 4 weeks under direct supervision and 8 weeks with semi-supervision. Cardiorespiratory fitness, body composition, and metabolic profile were evaluated at baseline and at the end of the 4th and 12th weeks. Core affect was measured during all training sessions. Results: Peak oxygen uptake improved in all groups after 4 and 12 weeks compared with baseline. Only the SSIT had reductions in body fat throughout the intervention. No improvements were observed in the metabolic profile across all groups. SSIT was perceived as more pleasurable than HIIT; however, there were no differences in affective responses between SSIT and MICT. Affective responses in-task (e.g. negative and positive peak, rate of change and affect at the end of the exercise session) predicted the HIIT and SSIT exercises attendance rate. Conclusion: Regardless of the exercise training protocol, overweight/obese inactive adults improved health outcomes, which suggests the prescribing HIIT, MICT, and SSIT in outdoor environments. SSIT should be considered in order to optimize the pleasure during training sessions. Affective response more positive in-task of the HIIT and SSIT is associated with greater attendance rate in these exercise protocols.

Oxygen uptake and heart rate responses to 4 weeks of RPE-guided handcycle training

PURPOSE

To investigate the efficacy of using Ratings of Perceived Exertion (RPE) to prescribe and regulate a 4-week handcycle training intervention.

METHODS

Thirty active adults, untrained in upper body endurance exercise, were divided into three groups to complete a 4-week intervention: (i) RPE-guided training (n = 10; 2 female), (ii) power output (PO)-guided (n = 10; 2 female) training, or (iii) non-training control (n = 10; 4 female). Training groups performed three sessions of handcycling each week. Oxygen uptake ([Formula: see text]), heart rate (HR), and Feeling Scale (FS) rating were collected during training sessions. RPE-guided training was performed at RPE 13. PO-guided training was matched for percentage of peak PO per session, based upon that achieved by the RPE-guided training group.

RESULTS

There were no differences in percentage of peak [Formula: see text] (66 ± 13% vs 61 ± 9%, p = 0.22), peak HR (75 ± 8% vs 71 ± 6%, p = 0.11) or FS rating (1.2 ± 1.9 vs 0.8 ± 1.6, p = 0.48) between RPE- and PO-guided training, respectively. The average coefficient of variation in percentage of peak HR between consecutive training sessions was 2.8% during RPE-guided training, and 3.4% during PO-guided training.

CONCLUSION

Moderate-vigorous intensity handcycling exercise can be prescribed effectively using RPE across a chronic training intervention, suggesting utility for practitioners in a variety of rehabilitation settings.

Don't stop focusing when it gets harder! The positive effects of focused attention on affective experience at high intensities

Experiencing negative affect during exercise partially explains high levels of physical inactivity. An important direction for research is to better understand how and why interindividual differences in affective experiences occur while exercising. The dual-mode theory suggests that the interaction of cognitive processes and interoceptive cues influence the affective response. Hence, attentional control in form of adopting an external or internal attentional focus could lead to different affective responses depending on intensity. This study examines possible interactions between self-selected running intensities and attentional focus on affect. Fifty-eight inexperienced runners (30.14 ± 9.19 years; 38% female) ran 9 × 3 min outdoors around a large pond. While running at three intensities, they were instructed to focus on their breathing, on the environment, or did not receive an instruction. Dependent measures were affect, heart rate, and speed. The results revealed a significant interaction between attentional focus and intensity on affect (p = .01, η²_p = .08). At subjectively perceived light intensity, participants' affective outcomes benefit from non-focusing attention, whereas during hard intensity the opposite seems helpful: to focus on breathing or to the environment. These findings shed new light on the interaction of focusing attention and running intensity to improve the affective experience.

The effect of whole-body high-intensity interval training on heart rate variability in insufficiently active adults

Background/objective

Low physical activity is a risk factor for cardiovascular disease (CVD) and all-cause morbidity and mortality. CVD alters heart rate variability (HRV). Interestingly, HRV can improve after exercise training. Therefore, this study aimed to examine the effect of whole-body high-intensity interval training (whole-body HIIT) on HRV in low physical activity adults.

Methods

Twenty-one low physical activity young adults were randomly assigned into two groups: whole-body HIIT (n = 10, females = 2/males = 8, age 22 ± 0.8 years, BMI 19.5 ± 1.0 kg/m²) and control (n = 11, females = 4/males = 7, age 21.7 ± 0.8 years, BMI 19.8 ± 0.9 kg/m²). A 6-week exercise program (3 days per week) consisting of 10 min of whole-body HIIT (burpees, mountain climbers, jumping jacks, and squats) at their maximal effort was administered. Baseline and post-training HRV (time domain: SDNN and RMSSD, frequency domain: LF, HF, and LF/HF ratio) and resting heart rate (HRrest) were recorded.

Results

The time domain parameter increased significantly in the whole-body HIIT group (SDNN; 50.95 ± 37.17 vs. 73.40 ± 40.70 ms, p < 0.05, RMSSD; 54.45 ± 56.04 vs. 81.26 ± 60.14 ms, p < 0.05). HRrest decreased significantly following training (73.94 ± 13.2 vs. 66.1 ± 10.8 bpm, p < 0.05). However, there were no significant differences in all frequency-domain parameters.

Conclusion

Six weeks of whole-body HIIT improved cardiovascular autonomic function in insufficiently active adults. Thus, whole-body HIIT might be considered an alternative exercise for reducing the risk of CVD.

The effect of two types of combined training on bio-motor ability adaptations in sedentary females

BACKGROUND

The purpose of this study was to compare the effects of combined training of high-volume/low intensity vs. low volume/high intensity on different bio-motor adaptations in sedentary women.

METHODS

Thirty sedentary healthy females (age, 22.1±3.3 yrs), were randomly assigned into: Control group (CG; n=10), High-Volume/low-intensity training group (HV; n=10); or High-Intensity/low-volume training group (HI; n=10). Training protocols were performed during 8 weeks, on 3 non-consecutive days a week.

RESULTS

Post-intervention, there were significant main effects of time and a group by time interaction for all body composition and performance variables (p ≤ 0.001), while no significant differences were found for changes in maximum heart rate. Pairwise comparisons revealed significant decreases in body fat percentage and speed test in HV and HI (p ≤ 0.001) after intervention, while anaerobic power significantly increased in HV and HI (p ≤ 0.001). The rating of perceived exertion (RPE) was significantly superior in HI than HV (p ≤ 0.05). Additionally, there were significant main effects of time and a group by time interaction for all 1-repetition maximum tests (p ≤ 0.001).

CONCLUSIONS

Combined interval training and resistance training were effective for improving bio-motor parameters in sedentary young women. HV training produced less RPE than HI training, which may potentially increase adherence to training protocols postintervention.

Systematic Reductions in Differential Ratings of Perceived Exertion Across a 2-Week Repeated-Sprint-Training Intervention That Improved Soccer Players' High-Speed-Running Abilities

PURPOSE

To quantify changes in differential ratings of perceived exertion (dRPE) across a 2-wk repeated-sprint-training intervention that improved high-intensity intermittent-running ability and linear speed of semiprofessional soccer players.

METHODS

Thirteen players completed 3 (sessions 1-3) or 4 (sessions 4-6) sets of 7 sprints (group 1 [n = 7]: 30-m straight; group 2 [n = 6]: 2 × 10-m shuttle), with 20 s and 4 min of recovery between sprints and sets, respectively. Postset perceptions of breathlessness (RPE-B) and leg-muscle exertion (RPE-L) were rated using the CR100 scale.

RESULTS

Overall, RPE-B (mean [SD]: 46 [13] arbitrary units [AU], "hard") was most likely higher than RPE-L (39 [13] AU, "somewhat hard," mean difference: 8 AU; 90% confidence limits [CLs]: ±2). Set-to-set increases in dRPE (in AU; 90% CL: approximately ±2) were large in session 1 (RPE-B: 15; RPE-L: 14), moderate in sessions 2-5 (RPE-B: 7-10; RPE-L: 7-8), and small (RPE-B: 6) to moderate (RPE-L: 7) in session 6. Across the intervention, RPE-B reduced moderately in sets 3 (-13; 90% CL: ±4) and 4 (-12; 90% CL: ±12) and RPE-L reduced by a small magnitude in set 3 (-5; 90% CL: ±6). The set 4 change in RPE-L was unclear (-11; 90% CL: ±13).

CONCLUSIONS

The authors observed systematic intrasession and intersession changes in dRPE across a 2-wk repeated-sprint-training intervention, with a fixed prescription of external load that improved semiprofessional soccer players' high-speed-running abilities. These findings could support dRPE as a measure of internal load and highlight its usefulness in evaluating repeated-sprint-training dose-response.

Development of a Self-Determination Theory-Based Physical Activity Intervention for Aged Care Workers: Protocol for the Activity for Well-being Program

Despite the well-established benefits of regular participation in physical activity, many Australians still fail to maintain sufficient levels. More self-determined types of motivation and more positive affect during activity have been found to be associated with the maintenance of physical activity behaviour over time. Need-supportive approaches to physical activity behaviour change have previously been shown to improve quality of motivation and psychological well-being. This paper outlines the development of a need-supportive, person-centred physical activity program for frontline aged-care workers. The program emphasises the use of self-determined methods of regulating activity intensity (affect, rating of perceived exertion and self-pacing) and is aimed at increasing physical activity behaviour and psychological well-being. The development process was undertaken in six steps using guidance from the Intervention Mapping framework: (i) an in-depth needs assessment (including qualitative interviews where information was gathered from members of the target population); (ii) formation of change objectives; (iii) selecting theory-informed and evidence-based intervention methods and planning their practical application; (iv) producing program components and materials; (v) planning program adoption and implementation, and (vi) planning for evaluation. The program is based in Self-Determination Theory (SDT) and provides tools and elements to support autonomy (the use of a collaboratively developed activity plan and participant choice in activity types), competence (action/coping planning, goal-setting and pedometers), and relatedness (the use of a motivational interviewing-inspired appointment and ongoing support in activity).

Time Flies When You're at RPE13: How Exercise Intensity Influences Perception of Time

Hanson, NJ and Lee, TL. Time flies when you're at RPE13: How exercise intensity influences perception of time. J Strength Cond Res 34(12): 3546-3553, 2020-Previous studies have shown that there are some changes in our perception of time during exercise, but the relationship between intensity level and these perceptions is unclear. Therefore, the purpose of this study was to determine the effect of exercise intensity on prospective time estimations. Twenty-two trained runners (10 male, 12 female; age 25 ± 6 years) participated in three 30-minute treadmill runs that were perceptually regulated at rating of perceived exertion (RPE) levels of 13 ("somewhat hard"), 15 ("hard"), and 17 ("very hard"). Prospective time assessments, in which subjects estimated durations of 1, 3, 7, and 20 seconds, were obtained immediately before exercise, during (at 10 and 20 minutes), and after exercise. A 3 (RPE) × 4 (timepoint) × 4 (estimated duration) repeated-measures analysis of variance was completed. There was a significant main effect of RPE level (p = 0.013). Post hoc tests revealed that time estimations at RPE17 were significantly lower than those at RPE13 (p = 0.021). The main effects of timepoint and estimated duration were not significant (both p ≥ 0.05), and no interactions were present. However, there was a trend for time estimations to decrease in all conditions as exercise progressed, with a rebound after cessation of exercise. This study showed a clear effect of exercise intensity on time perception. Specifically, the subjects perceived time to pass by more slowly as intensity increased.

Cardiorespiratory fitness moderates the effect of an affect-guided physical activity prescription: a pilot randomized controlled trial

Physical activity (PA) interventions have a clear role in promoting mental health. Current PA guidelines directed toward specific PA intensities may have negative effects on affective response to exercise, and affective response is an important determinant of PA adherence. In this randomized trial of 67 previously inactive adults, we compared the effects of a PA prescription emphasizing the maintenance of positive affect to one emphasizing a target heart rate, and tested the extent to which the effect of the affect-guided prescription on PA is moderated by cardiorespiratory fitness (CRF). We found the effect of an affect-guided prescription was significantly moderated by CRF. At one week, for participants with lower CRF (i.e. poor conditioning), the affect-guided prescription resulted in significantly greater change in PA minutes (M = 240.8) than the heart rate-guided prescription (M = 165.7), reflecting a moderate-sized effect (d = .55). For those with higher CRF (i.e. good conditioning), the means were in the opposite direction but not significantly different. At one month, the same pattern emerged but the interaction was not significant. We discuss the implications of these findings for the type of PA prescriptions offered to individuals in need.