Brief Intense Stair Climbing Improves Cardiorespiratory Fitness

A Mobile Health Team Challenge to Promote Stepping and Stair Climbing Activities: Exploratory Feasibility Study

Background

Mobile health (mHealth) approaches are growing in popularity as a means of addressing low levels of physical activity (PA).

Objective

This study aimed to determine the validity of wearables in measuring step count and floor count per day and assess the feasibility and effects of a 6-week team challenge intervention delivered through smartphone apps.

Methods

Staff and students from a public university were recruited between 2015 and 2016. In phase 1, everyone wore a Fitbit tracker (Charge or Charge HR) and an ActiGraph for 7 days to compare daily step count estimated by the two devices under free-living conditions. They were also asked to climb 4 bouts of floors in an indoor stairwell to measure floor count which was compared against direct observation. In phase 2, participants were allocated to either a control or intervention group and received a Fitbit tracker synced to the Fitbit app. Furthermore, the intervention group participants were randomized to 4 teams and competed in 6 weekly (Monday to Friday) real-time challenges. A valid day was defined as having 1500 steps or more per day. The outcomes were as follows: (1) adherence to wearing the Fitbit (ie, number of days in which all participants in each group were classified as valid users aggregated across the entire study period), (2) mean proportion of valid participants over the study period, and (3) the effects of the intervention on step count and floor count determined using multiple linear regression models and generalized estimating equations (GEEs) for longitudinal data analysis.

Results

In phase 1, 32 of 40 eligible participants provided valid step count data, whereas all 40 participants provided valid floor count data. The Fitbit trackers demonstrated high correlations (step count: Spearman ρ=0.89; P<.001; floor count: Spearman ρ=0.98; P<.001). The trackers overestimated step count (median absolute error: 17%) but accurately estimated floor count. In phase 2, 20 participants each were allocated to an intervention or control group. Overall, 24 participants provided complete covariates and valid PA data for analyses. Multiple linear regressions revealed that the average daily steps was 15.9% higher for the intervention group (95% CI −8.9 to 47.6; P=.21) during the final two intervention weeks; the average daily floors climbed was 39.4% higher (95% CI 2.4 to 89.7; P=.04). GEE results indicated no significant interaction effects between groups and the intervention week for weekly step count, whereas a significant effect (P<.001) was observed for weekly floor count.

Conclusions

The consumer wearables used in this study provided acceptable validity in estimating stepping and stair climbing activities, and the mHealth-based team challenge interventions were feasible. Compared with the control group, the participants in the intervention group climbed more stairs, so this can be introduced as an additional PA promotion target in the context of mHealth strategies. Methodologically rigorous studies are warranted to further strengthen this study’s findings.

Acute high-intensity and moderate-intensity interval exercise do not change corticospinal excitability in low fit, young adults

Previous research has demonstrated a lack of neuroplasticity induced by acute exercise in low fit individuals, but the influence of exercise intensity is unclear. In the present study, we assessed the effect of acute high-intensity (HI) or moderate-intensity (MOD) interval exercise on neuroplasticity in individuals with low fitness, as determined by a peak oxygen uptake (VO2peak) test (n = 19). Transcranial magnetic stimulation (TMS) was used to assess corticospinal excitability via area under the motor evoked potential (MEP) recruitment curve before and following training. Corticospinal excitability was unchanged after HI and MOD, suggesting no effect of acute exercise on neuroplasticity as measured via TMS in sedentary, young individuals. Repeated bouts of exercise, i.e., physical training, may be required to induce short-term changes in corticospinal excitability in previously sedentary individuals.

Physiological basis of brief vigorous exercise to improve health

This review considers the physiological basis of brief vigorous exercise to improve health, with a focus on cardiorespiratory fitness (CRF) and glycaemic control, and the potential underlying mechanisms involved. We defined 'brief' as a protocol lasting ≤15 min including warm-up, cool-down and recovery, and involving a total of ≤5 min of 'vigorous' exercise, which was classified as meeting or exceeding the lower end of the range for this relative intensity as per the criteria from the American College of Sports Medicine. The physiological mechanisms responsible for the increase in CRF, as measured by maximal oxygen update ( V ̇ O 2 max ), after brief vigorous exercise are unclear and likely depend on various factors including the specific nature of the intervention as well as the time course of the response. Limited available evidence suggests the potential for an increased oxygen extraction by active muscle (i.e. greater arterio-venous oxygen difference), since an increase in V ̇ O 2 max has been reported after several weeks of brief vigorous exercise despite no measurable change in cardiac output. Emerging evidence indicates that brief vigorous exercise can improve glycaemic control, suggesting that this type of exercise could potentially play a role in the prevention and management of type 2 diabetes. The acute response is not well characterized but several studies have shown that several weeks of vigorous exercise improves estimates of insulin sensitivity as determined by various methods including by hyperinsulinaemic-euglycaemic clamp. The physiological mechanisms underlying improved CRF and glycaemic control after brief vigorous exercise, and the broader impact on health, remain fruitful areas of investigation.

Time-efficient physical training for enhancing cardiovascular function in midlife and older adults: promise and current research gaps

Cardiovascular diseases (CVD) remain the leading cause of death in developed societies, and "midlife" (50-64 yr) and older (65+) men and women bear the great majority of the burden of CVD. Much of the increased risk of CVD in this population is attributable to CV dysfunction, including adverse changes in the structure and function of the heart, increased systolic blood pressure, and arterial dysfunction. The latter is characterized by increased arterial stiffness and vascular endothelial dysfunction. Conventional aerobic exercise training, as generally recommended in public health guidelines, is an effective strategy to preserve or improve CV function with aging. However, <40% of midlife and older adults meet aerobic exercise guidelines, due in part to time availability-related barriers. As such, there is a need to develop evidence-based time-efficient exercise interventions that promote adherence and optimize CV function in these groups. Two promising interventions that may meet these criteria are interval training and inspiratory muscle strength training (IMST). Limited research suggests these modes of training may improve CV function with time commitments of ≤60 min/wk. This review will summarize the current evidence for interval training and IMST to improve CV function in midlife/older adults and identify key research gaps and future directions.

Disrupting prolonged sitting reduces IL-8 and lower leg swell in active young adults

Background

Evidence suggests that disrupting prolonged bouts of sitting with short bouts of physical activity can significantly reduce blood glucose and improve insulin sensitivity; however, limited research is available on the impact of such disruptions on inflammation and swelling. The purpose of this study was to determine whether short bouts of exercise performed each hour during a 4 h sitting session were able to negate the effects of prolonged sitting (PS) on several cardiometabolic outcomes.

Methods

Eligible participants (n = 10) attended two laboratory sessions: PS (uninterrupted sitting for 4 h) and disrupted sitting (DS; 4 h sitting session disrupted by 3 min of exercise each hour (60-s warm-up at 50 W, 5 s of unloaded cycling, 20-s sprint at 5% body weight, and 95-s cool-down at 50 W)). The exercise bouts were performed at minute 60, 120, and 180. Blood and saliva samples, and measures of heart rate and blood pressure were assessed before (T1) and after (T2) each session; leg swell was measured continuously.

Results

Concentrations of salivary IL-8 increased during PS (T1: 0.19 ± 0.32; T2: 0.50 ± 1.00 pg/μg of protein) but decreased during DS (T1: 0.41 ± 0.23; T2: 0.22 ± 0.11 pg/μg of protein, d: 0.51, p = 0.002). Leg swell increased and plateaued in PS, but was attenuated during DS.

Conclusion

It appears that short bouts of exercise significantly reduce swelling in the lower leg and IL-8 levels in the saliva, indicating that even among healthy, active, young adults, disrupting prolonged sitting can significantly reduce swelling and systemic inflammation.

Effects of a Brief Stair-Climbing Intervention on Cognitive Performance and Mood States in Healthy Young Adults

OBJECTIVE

Previous studies focused on the benefits of acute exercise on cognition and mood have mostly used specialized laboratory-based equipment, thus little is known about how such protocols generalize to naturalistic settings. Stair climbing is a simple and readily accessible means of exercise that can be performed in naturalistic settings (e.g., at home or at the workplace). In the present study we examined the effects of stair-climbing intervals on subsequent cognitive performance and mood in healthy young adults.

METHOD

Thirty-two undergraduate students (M age = 19.4 years, SD = 1.3; 21 females) completed a controlled randomized crossover trial with session order counterbalanced across participants. Participants visited the lab on two occasions, one week apart, and completed one control session (no exercise) and one stair-climbing session (3 × 1 min stair-climbing intervals) with cognitive performance and mood assessed at the end of each session.

RESULTS

Repeated measures ANCOVA revealed that males (Hedges' g av = 0.45) showed better switching performance following the stair climbing but females (Hedges' g av < 0.03) did not. Participants felt more energetic (Hedges' g av = 1.05), less tense (Hedges' g av = 0.61), and less tired (Hedges' g av = 0.43) following the stair climbing. In addition, higher exercise intensity during the stair climbing predicted better subsequent switching performance and higher energetic ratings.

CONCLUSION

These findings indicate that short bouts of stair climbing in a naturalistic setting can induce cognitive benefits for more challenging tasks, albeit only in males, indicating a sex-specific effect. Short bouts of stair climbing can be a practical approach to increase feelings of energy in daily life.

Learnt effects of environmental cues on transport-related walking; disrupting habits with health promotion?

Background

In Ecological models, physical environments can be important determinants of transport-related walking. With repeated exposure to the same environment, learning of a linkage between the cues in the environment and walking should occur. Subsequent encounters with the cues can prompt the behaviour relatively automatically. No studies have experimentally tested the potential learning of this linkage between cues and behaviour. Choices between stairs and escalators in public access settings were employed to test this premise for transport-related walking.

Methods

Three studies investigated the effects of visual cues on stair/escalator choices (combined n = 115,062). In quasi-experimental, interrupted time-series designs, observers audited choices in public access settings. Design alone phases with art or coloured backgrounds were compared with design plus message phases in which verbal health promotion messages were superimposed on the visual cues. Analyses used bootstrapped logistic regression.

Results

In initial studies, the design alone phases had no effect whereas subsequent design plus message phases reduced escalator choice. In two further studies, a 5–6 week design plus message phase that reduced escalator choice preceded a design alone phase. The visual background behind the successful health promotion message was reintroduced four weeks after the intervention was removed. The visual cue of design alone reduced escalator choice after it had been paired with the verbal health promotion message. There were no differences between art and coloured backgrounds.

Conclusion

These studies demonstrate for the first time a learnt linkage between transport-related walking and environmental cues. Discussion focuses on the mechanisms that may underlie this learning and cues in the environment that are relevant to transport-related walking.

Evidence-Based, High-Intensity Exercise and Physical Activity for Compressing Morbidity in Older Adults: A Narrative Review

Recent research in exercise science has important applications for middle-aged and older adults and points to how the programming of individual and multicomponent interventions including theory-based health behavior change strategies may be improved to compress morbidity by delaying or reducing the disabling process. High-intensity interval training and sprint interval training until recently were seen as only applicable to athletes. But recent lab-based research has adapted these interventions for even older adults and demonstrated their safety with beneficial outcomes on cardiometabolic risk factors comparable to or surpassing the usual lower- to moderate-intensity endurance training, and their potential translatability by showing the efficacy of much lower duration and frequency of training, even by systematic stair climbing. Moreover, people report positive affect while engaged in such training. For a century, resistance training was conceived as weightlifting with heavy weights required. Recent research has shown that using a higher degree of effort with lighter to moderate resistance in simple, time efficient protocols result in gains in strength and muscle mass similar to heavy resistance, as well as improvement of cardiometabolic risk factors, strength, body composition, and cognitive, affective, and functional abilities. More effort-based resistance training with moderate resistance may make resistance training more appealing and accessible to older adults. A key potential translational finding is that with correct technique and a high degree of effort, training with inexpensive, portable elastic bands, useable virtually anywhere, can provide appreciable benefits. More emphasis should be placed on long-term, translational interventions, resources, and programs that integrate interval and resistance trainings. This work may improve public health programs for middle-aged and older adults and reflects an emerging evidence base.

Do stair climbing exercise “snacks” improve cardiorespiratory fitness?

We investigated the effect of stair climbing exercise “snacks” on peak oxygen uptake. Sedentary young adults were randomly assigned to perform 3 bouts/day of vigorously ascending a 3-flight stairwell (60 steps), separated by 1–4 h of recovery, 3 days/week for 6 weeks, or a nontraining control group (n = 12 each). Peak oxygen uptake was higher in the climbers after the intervention (P = 0.003), suggesting that stair climbing “snacks” are effective in improving cardiorespiratory fitness, although the absolute increase was modest.

Prevalence and predictors of dropout from high-intensity interval training in sedentary individuals: A meta-analysis

Recent evidence suggests that high-intensity interval training (HIIT) is an effective method to improve fitness and various health markers. However, the tolerability and acceptability of HIIT among sedentary individuals is currently controversially discussed. Therefore, our objective was to investigate the prevalence and predictors of dropout among sedentary individuals in HIIT-based exercise interventions. MEDLINE/PubMed, SPORTDiscus, and Web of Science were searched systematically for relevant articles until 06/2018. Studies included were required to (a) be written in English, (b) include sedentary healthy adults, (c) use some form of HIIT without any complementary intervention, (d) last ≥4 weeks, (e) report detailed description of the applied HIIT protocol, and (f) report data that allow calculation of a dropout rate. Fifty-five studies reporting results from 67 HIIT interventions with 1318 participants met the eligibility criteria. The trim and fill adjusted pooled dropout rate across all interventions was 17.6% (95% confidence interval 14.2-21.5%). Dropout rates were significantly lower in cycling-based interventions compared with studies using running/walking as exercise modality (P < 0.001). Longer session time (β = 0.02, P < 0.05), higher time effort/week (β = 0.005, P < 0.05), and overall time effort/intervention (β = 0.0003, P < 0.05) predicted greater dropout. Exercise intensity was not related to dropout. Our data suggest that HIIT-based interventions are tolerable and acceptable for previously sedentary individuals, exhibiting generally lower dropout rates than commonly reported for traditional exercise programs. Given the association between HIIT volume and dropouts, future studies should further focus on identifying the minimally effective dose of practical HIIT for improving health status. Such efforts would be important to increase implementation and public health impact of HIIT.

Self-reported tolerance of the intensity of exercise influences affective responses to and intentions to engage with high-intensity interval exercise

This study investigated the effect of self-reported tolerance of the intensity of exercise on affective responses to, self-efficacy for and intention to repeat low-volume high-intensity interval exercise (HIIE). Thirty-six healthy participants (mean age 21 ± 2 years) were split into high tolerance (HT; n = 19), low tolerance (LT; n = 9), and very low tolerance (VLT; n = 8) of exercise intensity groups. Participants completed 10 × 6 s cycle sprints with 60 s recovery. Affective valence and perceived activation were measured before exercise, after sprints 2, 4, 6, 8, 10, and 20 min post-HIIE. Intention and self-efficacy were assessed 20 min post-HIIE. Affective valence was significantly lower in VLT vs. LT (P = 0.034, d = 1.01-1.14) and HT (P = 0.018, d = 1.34-1.70). Circumplex profiles showed a negative affective state in VLT only. The VLT group had lower intentions to repeat HIIE once and three times per week than HT (P < 0.001, d = 1.87 and 1.81, respectively) and LT (P = 0.107, d = 0.85; P = 0.295, d = 0.53, respectively). Self-efficacy was not influenced by tolerance. Self-reported tolerance of exercise intensity influences affective responses to and intentions to engage with HIIE.

Research into the Health Benefits of Sprint Interval Training Should Focus on Protocols with Fewer and Shorter Sprints

Over the past decade, it has been convincingly shown that regularly performing repeated brief supramaximal cycle sprints (sprint interval training [SIT]) is associated with aerobic adaptations and health benefits similar to or greater than with moderate-intensity continuous training (MICT). SIT is often promoted as a time-efficient exercise strategy, but the most commonly studied SIT protocol (4–6 repeated 30-s Wingate sprints with 4 min recovery, here referred to as ‘classic’ SIT) takes up to approximately 30 min per session. Combined with high associated perceived exertion, this makes classic SIT unsuitable as an alternative/adjunct to current exercise recommendations involving MICT. However, there are no indications that the design of the classic SIT protocol has been based on considerations regarding the lowest number or shortest duration of sprints to optimise time efficiency while retaining the associated health benefits. In recent years, studies have shown that novel SIT protocols with both fewer and shorter sprints are efficacious at improving important risk factors of noncommunicable diseases in sedentary individuals, and provide health benefits that are no worse than those associated with classic SIT. These shorter/easier protocols have the potential to remove many of the common barriers to exercise in the general population. Thus, based on the evidence summarised in this current opinion paper, we propose that there is a need for a fundamental change in focus in SIT research in order to move away from further characterising the classic SIT protocol and towards establishing acceptable and effective protocols that involve minimal sprint durations and repetitions.

Targeting Postprandial Hyperglycemia With Physical Activity May Reduce Cardiovascular Disease Risk. But What Should We Do, and When Is the Right Time to Move?

Physical inactivity and excessive postprandial hyperglycemia are two major independent risk factors for type 2 diabetes and cardiovascular-related mortality. Current health policy guidelines recommend at least 150 min of physical activity per week coupled with reduced daily sedentary behavior by interrupting prolonged sitting with bouts of light activity every 30-min. This evidence-based strategy promotes health and quality of life. Since modern lifestyle enforces physical inactivity through motorized transportation and seated office working environments, this review examines the practical strategies (standing, walking, stair climbing, and strength-based circuit exercises) for reducing sitting time and increasing activity during the workday. Furthermore, since postprandial hyperglycemia poses the greatest relative risk for developing type 2 diabetes and its cardiovascular complications, this review examines a novel hypothesis that interrupting sitting time would be best focused on the postprandial period in order to optimize blood glucose control and maximize cardiometabolic health. In doing so, we aim to identify the science gaps which urgently need filling if we are to optimize healthcare policy in this critical area.

The effect of brief intermittent stair climbing on glycemic control in people with type 2 diabetes: a pilot study

We examined the effect of brief intermittent stair climbing exercise on glycemic control using continuous glucose monitoring in people with type 2 diabetes (n = 7, 5 men; 2 women; age, 21-70 years). The protocol involved three 60-s bouts of vigorously ascending and slowly descending a flight of stairs. Mean 24-h blood glucose was unchanged after an acute session (p = 0.43) and following 18 sessions over 6 weeks (p = 0.13). The protocol was well tolerated by participants but seemingly insufficient to alter glycemic control.

Effects of low-volume high-intensity interval training in a community setting: a pilot study

PURPOSE

High-intensity interval training (HIIT) is emerging as an effective and time-efficient exercise strategy for health promotion. However, most HIIT studies are conducted in laboratory settings and evidence regarding the efficacy of time-efficient "low-volume" HIIT is based mainly on demanding "all-out" protocols. Thus, the aim of this pilot study was to assess the feasibility and efficacy of two low-volume (≤ 30 min time-effort/week), non-all-out HIIT protocols, performed 2 ×/week over 8 weeks in a community-based fitness centre.

METHODS

Thirty-four sedentary men and women were randomised to either 2 × 4-min HIIT (2 × 4-HIIT) or 5 × 1-min HIIT (5 × 1-HIIT) at 85-95% maximal heart rate (HR_max), or an active control group performing moderate-intensity continuous training (MICT, 76 min/week) at 65-75% HR_max.

RESULTS

The exercise protocols were well tolerated and no adverse events occurred. 2 × 4-HIIT and 5 × 1-HIIT exhibited lower dropout rates (17 and 8 vs. 30%) than MICT. All training modes improved VO_2max (2 × 4-HIIT: + 20%, P < 0.01; 5 × 1-HIIT: + 27%, P < 0.001; MICT: + 16%, P < 0.05), but the HIIT protocols required 60% less time commitment. Both HIIT protocols and MICT had positive impact on cholesterol profiles. Only 5 × 1-HIIT significantly improved waist circumference (P < 0.05) and subjective work ability (P < 0.05).

CONCLUSIONS

The present study indicates that low-volume HIIT can be feasibly implemented in a community-based setting. Moreover, our data suggest that practical (non-all-out) HIIT that requires as little as 30 min/week, either performed as 2 × 4-HIIT or 5 × 1-HIIT, may induce significant improvements in VO_2max and cardiometabolic risk markers.

High-intensity body weight training is comparable to combined training in changes in muscle mass, physical performance, inflammatory markers and metabolic health in postmenopausal women at high risk for type 2 diabetes mellitus: A randomized controlled clinical trial

OBJECTIVE

This study compared the effects of 12 weeks of high-intensity interval body weight training (HIBWT) with combined training (COMT; aerobic and resistance exercises on body composition, a 6-minute walk test (6MWT; physical performance), insulin resistance (IR) and inflammatory markers in postmenopausal women (PW) at high risk of type 2 diabetes mellitus (TDM2).

METHODS

In this randomized controlled clinical study, 16 PW at high risk of TDM2 were randomly allocated into two groups: HIBWT (n = 8) and COMT (n = 8). The HIBWT group performed a training protocol (length time ~28 min) consisting of ten sets of 60 s of high intensity exercise interspersed by a recovery period of 60 s of low intensity exercise. The COMT group performed a training protocol (length time ~60 min) consisting of a 30 min walk of moderate intensity following by five resistance exercises. All training sessions were performed in the university gym facility three days a week (no consecutive days) for 12 weeks. All outcomes (body composition, muscle function, and IR and inflammatory markers) were assessed at the baseline and at the end of the study.

RESULTS

Both groups increased (P < 0.05) muscle mass index (MMI), 6MWT, and interleukin 1 receptor antagonist and decreased fasting glucose, glycated hemoglobin_, Insulin, HOMA-IR, and monocyte chemoattractant protein-1 (trend, P = 0.056). HIBWT effects were indistinguishable (P > 0.05) from the effects of COMT. There was a significant (P < 0.05) interaction of time by the group in muscle strength, indicating that only the COMT increased the muscle strength.

CONCLUSIONS

This study suggests that changes in HOMA, IL-1ra, 6MWT, and MMI with HITBW are similar when compared to COMT in PW at high risk of TDM2.

TRIAL REGISTRATION

The patients were part of a 12-week training study (ClinicalTrials.gov Identifier: NCT03200639).

A scoping review of the psychological responses to interval exercise: is interval exercise a viable alternative to traditional exercise?

While considerable evidence suggests that interval exercise confers numerous physiological adaptations linked to improved health, its psychological consequences and behavioural implications are less clear and the subject of intense debate. The purpose of this scoping review was to catalogue studies investigating the psychological responses to interval exercise in order to identify what psychological outcomes have been assessed, the research methods used, and the results. A secondary objective was to identify research issues and gaps. Forty-two published articles met the review inclusion/exclusion criteria. These studies involved 1258 participants drawn from various active/inactive and healthy/unhealthy populations, and 55 interval exercise protocols (69% high-intensity interval training [HIIT], 27% sprint interval training [SIT], and 4% body-weight interval training [BWIT]). Affect and enjoyment were the most frequently studied psychological outcomes. Post-exercise assessments indicate that overall, enjoyment of, and preferences for interval exercise are equal or greater than for continuous exercise, and participants can hold relatively positive social cognitions regarding interval exercise. Although several methodological issues (e.g., inconsistent use of terminology, measures and protocols) and gaps (e.g., data on adherence and real-world protocols) require attention, from a psychological perspective, the emerging data support the viability of interval exercise as an alternative to continuous exercise.

The efficacy of unsupervised home-based exercise regimens in comparison to supervised laboratory-based exercise training upon cardio-respiratory health facets

Supervised high-intensity interval training (HIIT) can rapidly improve cardiorespiratory fitness (CRF). However, the effectiveness of time-efficient unsupervised home-based interventions is unknown. Eighteen volunteers completed either: laboratory-HIIT (L-HIIT); home-HIIT (H-HIIT) or home-isometric hand-grip training (H-IHGT). CRF improved significantly in L-HIIT and H-HIIT groups, with blood pressure improvements in the H-IHGT group only. H-HIIT offers a practical, time-efficient exercise mode to improve CRF, away from the laboratory environment. H-IHGT potentially provides a viable alternative to modify blood pressure in those unable to participate in whole-body exercise.