Influence of warm-up duration and recovery interval prior to exercise on anaerobic performance

Effect of rest duration between sets on fatigue and recovery after short intense plyometric exercise

Plyometric training is characterized by high-intensity exercise which is performed in short term efforts divided into sets. The purpose of the present study was twofold: first, to investigate the effects of three distinct plyometric exercise protocols, each with varying work-to-rest ratios, on muscle fatigue and recovery using an incline-plane training machine; and second, to assess the relationship between changes in lower limb muscle strength and power and the biochemical response to the three exercise variants employed. Forty-five adult males were randomly divided into 3 groups (n = 15) performing an exercise of 60 rebounds on an incline-plane training machine. The G0 group performed continuous exercise, while the G45 and G90 groups completed 4 sets of 15 repetitions, each set lasting 45 s with 45 s rest in G45 (work-to-rest ratio of 1:1) and 90 s rest in G90 (1:2 ratio). Changes in muscle torques of knee extensors and flexors, as well as blood lactate (LA) and ammonia levels, were assessed before and every 5 min for 30 min after completing the workout. The results showed significantly higher (p < 0.001) average power across all jumps generated during intermittent compared to continuous exercise. The greatest decrease in knee extensor strength immediately post-exercise was recorded in group G0 and the least in G90. The post-exercise time course of LA changes followed a similar pattern in all groups, while the longer the interval between sets, the faster LA returned to baseline. Intermittent exercise had a more favourable effect on muscle energy metabolism and recovery than continuous exercise, and the work-to-rest ratio of 1:2 in plyometric exercises was sufficient rest time to allow the continuation of exercise in subsequent sets at similar intensity.

Hip and Trunk Variables in University Students with and without Recurrent Low Back Pain

Background

Low back pain (LBP) is a leading cause of disability. Recurrent low back pain (rLBP) is defined as two or more episodes of LBP in a 12-month period, each lasting more than 24 hours and separated by at least one pain-free month. Many studies have shown that hip and trunk variables have an influence on LBP. However, most of these are studies of participants with acute or chronic LBP rather than rLBP.

Purpose

To examine the difference between hip and trunk variables of university students with and without rLBP.

Study Design

Cross-Sectional.

Methods

Participants with and without rLBP between 18 and 35 years of age not currently undergoing clinical orthopedic care were recruited for this cross-sectional study. Bilateral hip range of motion (ROM) and trunk ROM were measured with a goniometer or measuring tape (hip motions in all planes along with trunk flexion, extension, and lateral flexion). Strength of the hip extensors, abductors, and external rotators was measured using a handheld dynamometer, and a single-leg bridge endurance test was performed to assess differences and correlations between outcomes.

Results

Twenty-six subjects aged 18 to 35 years with rLBP (n=10) and without rLBP (n=16) participated. Statistically significant differences between the two groups were found for right and left hip flexion (p = 0.029 and 0.039, respectively), right hip adduction (p = 0.043), and right hip extension (p = 0.021). No significant differences were found between groups for strength, endurance, or other ROM measures.

Conclusion

The findings of this study show statistically significant although clinically non-meaningful differences in hip flexion, extension, and adduction ROM in the rLBP group compared to the control group. This lack of clinically meaningful difference may be relevant to testing procedures and treatment of patients or athletes with rLBP. This study also suggests that hip strength and endurance may not play a major role in the development or treatment of rLBP. Level of Evidence: 3.

Warm-Up Intensity and Time-Course Effects on Jump Height under Cold Conditions

With this study, we aimed to investigate the effects of different warm-up intensities on counter-movement jump (CMJ) performance over time under cold conditions. Eleven male collegiate athletes volunteered. The participants performed high-intensity warm-up (HWU) at 80% VO2max and moderate-intensity warm-up (MWU) at 60% VO2max for 15 min on a bicycle ergometer in a laboratory room at 10 °C. CMJ height, vastus lateralis muscle temperature, heart rate, and perceived fatigue were measured before warm-up (Pre), immediately after (Post 0), 10 min after (Post 10), and 20 min after (Post 20). Significant main effects and interactions were found for CMJ height (time, p < 0.001 and ηp2 = 0.859; interaction, p = 0.007 and ηp2 = 0.327). HWU significantly increased CMJ height at Post 0 to Post 20 compared to that at Pre (p < 0.01), whereas MWU increased CMJ height at Post 0 only compared to that at Pre (p < 0.001). The results indicate that HWU achieved an increase in CMJ height for 20 min. MWU changed CMJ height instantly, but the change did not last compared to HWU in a cold environment.

Usefulness of Portable Device to Establish Differences in Muscle Oxygenation Between the Wingate Test and Graded Exercise Test: Effect of Gender on Anaerobic and Aerobic Capacity in Speed Skaters

The aim of this study was to compare the oxygenation response in the vastus lateralis muscle (SmO₂) in two types of tests: supramaximal and maximal. Furthermore, gender differences in SmO₂ response to test exercise were assessed and the usefulness of muscle oxygenation measurements in the assessment of anaerobic and aerobic capacity was determined. The Wingate test (WAnT) and the graded exercise test (GXT) to exhaustion were performed on a cycle ergometer to examine 13 female and 14 male speed skaters from the junior and U23 national teams. During both tests, SmO₂ of the vastus lateralis muscle was recorded by near-infrared spectroscopy at baseline (at rest or post warm-up), at exercise, and during recovery. The most significant SmO₂ indices (differences between baseline and post-exercise indices and half time for SmO₂ to reach the maximal post-exercise value) were not significantly different between the tests. Gender was also not a differentiating factor in muscle oxygenation regardless of test type. In the GXT test, half time required for SmO₂ to reach the maximal value correlated negatively with VO_2max and test duration, thus confirming the usefulness of SmO₂ measurements in the assessment of the aerobic capacity of speed skaters. In contrast, the WAnT test showed no significant correlations between exercise indices and muscle oxygenation indices. From the standpoint of the assessment of anaerobic capacity, SmO₂ measurements showed little diagnostic value.

Warm-Up With Added Respiratory Dead Space Volume Mask Improves the Performance of the Cycling Sprint Interval Exercise: Cross-Over Study

Special breathing exercises performed during warm-up lead to hypercapnia and stimulation of mechanisms leading to increased exercise performance, but the effect of a device that increases the respiratory dead space volume (ARDSv) during warm-up has not been studied. The purpose of this study was to investigate the effect of 10 min warm-up with ARDSv on performance, physiological and biochemical responses during sprint interval cycling exercise (SIE). During four laboratory visits at least 72 h apart, they completed: (1) an incremental exercise test (IET) on a cycloergometer, (2) a familiarization session, and cross-over SIE sessions conducted in random order on visits (3) and (4). During one of them, 1200 mL of ARDSv was used for breathing over a 10-min warm-up. SIE consisted of 6 × 10-s all-out bouts with 4-min active recovery. Work capacity, cardiopulmonary parameters, body temperature, respiratory muscle strength, blood acid-base balance, lactate concentration, and rating of perceived exertion (RPE) were analyzed. After warm-up with ARDSv, P ET CO2 was 45.0 ± 3.7 vs. 41.6 ± 2.5 (mm Hg) (p < 0.001). Body temperature was 0.6 (°C) higher after this form of warm-up (p < 0.05), bicarbonate concentration increased by 1.8 (mmol⋅L-1) (p < 0.01). As a result, work performed was 2.9% greater (p < 0.01) compared to the control condition. Respiratory muscle strength did not decreased. Warming up with added respiratory dead space volume mask prior to cycling SIE produces an ergogenic effect by increasing body temperature and buffering capacity.

The Effects of Caffeine and Citrus Aurantium on Performance During Repeated Maximal Anaerobic Exercise Bouts in Habitual Caffeine Users

ABSTRACT

McLester, CN, Bailey, P, Bechke, EE, Williamson, CM, McLester, JR, and Kliszczewicz, B. The effects of caffeine and Citrus aurantium on performance during repeated maximal anaerobic exercise bouts in habitual caffeine users. J Strength Cond Res 35(12): 3394-3399, 2021-The combination of caffeine (CAF) and Citrus aurantium (CA) have demonstrated the potential to improve various types of performance. To date, few studies have explored this relationship in purely anaerobic-based exercise. Therefore, the purpose of this study was to examine the influence of an acute dose of CAF + CA on peak anaerobic performance and the attenuation of power over multiple anaerobic bouts and to determine any differences in perceived effort or fatigue. Ten active men (25.1 ± 3.9 years) who habitually consumed caffeine volunteered to perform repeated anaerobic bouts on a cycle ergometer on 2 separate days, consuming either a placebo or 100 mg CAF + 100 mg CA. Significance was set at p ≤ 0.05 and repeated measures analysis of variance showed no main effects for peak power p = 0.520, mean power p = 0.926, minimum power p = 0.321, total work p = 0.924, time to peak power p = 0.536, or rate of fatigue p = 0.284. There was a time effect for all variables (p ≤ 0.05) with the exception of time to peak power (p = 0.181). There were no differences in any measures of perceived effort or fatigue between conditions (p ≥ 0.05), but there were time-dependent differences observed each day (p ≤ 0.05). Overall, an acute dosage of 100 mg CAF and 100 mg CA did not elicit any differences in anaerobic performance or in perceived measures of effort and fatigue in young males who habitually consume caffeine. Therefore, caution should be used when pairing CAF and CA for the goal of improving anaerobic performance, because no clear benefit was realized in this population at this dosage.

Warm-up durations in a hot-dry climate affect thermoregulation, mean power-output and fatigue, but not peak power in specific soccer repeated-sprint ability

Background

This study addressed the lack of data on the effect of warm-up (WU) duration in hot-dry climate (~ 30 °C; ~ 18% RH), on thermoregulation, muscular power-output, and fatigue after specific soccer repeated-sprint test (RSA).

Methods

Eleven amateur soccer players participated in a cross-over randomized study and they underwent the Bangsbo repeated-sprint test, after three WU durations (i.e. WU10, WU15 and WU20 min) at 70% of MAV, and on different days. Peak power (PP), mean power (MP) and the fatigue index (FI) were recorded and analyzed. Likewise, heart rate (HR), tympanic temperature (T_tym), mean body temperature (MBT) and rating of perceived exertion (RPE) were recorded during each session.

Results

The repeated measure ANOVA showed that MP improved after WU15 in comparison to WU10 and WU20 (p = 0.04 and p = 0.001; respectively). Nonetheless, no significant effect on PP was recorded after all WU durations. FI during RSA increased after WU20 in comparison to WU15 and WU10 (p < 0.001 and p = 0.003; respectively). Higher RPE values (p < 0.001) were recorded after WU15 and WU20 in comparison to WU10 duration. The two-way ANOVA showed higher ΔT_tym and ΔMBT values after WU15 and WU20 compared to WU10 (p = 0.039 and p < 0.001for T_tym; p = 0.005 and p < 0.001 for MBT, respectively).

Conclusions

The WU15 at 70% of MAV better assists mean power-output during soccer RSA in hot-dry (~ 30 °C; 18% RH) climate, but not peak power. Reducing WU duration up to 10 min seems to be insufficient to induce beneficial physiological changes necessary for optimizing repeated-sprint performance, while its extension up to 20 min remains detrimental for muscular power and induces higher fatigue.

Acute effects of caffeine supplementation on resistance exercise, jumping, and Wingate performance: no influence of habitual caffeine intake

This study explored the influence of habitual caffeine intake on the acute effects of caffeine ingestion on resistance exercise, jumping, and Wingate performance. Resistance-trained males were tested following the ingestion of caffeine (3 mg/kg) and placebo (3 mg/kg of dextrose). Participants were classified as low caffeine users (n = 13; habitual caffeine intake: 65 ± 46 mg/day) and as moderate-to-high caffeine users (n = 11; habitual caffeine intake: 235 ± 82 mg/day). Exercise performance was evaluated by measuring: (a) movement velocity, power, and muscular endurance in the bench press; (b) countermovement jump; and, (c) a Wingate test, performed in that order. Two-way repeated-measures ANOVA revealed a significant main effect (p < 0.05) for condition in the majority of analyzed exercise outcomes. In all cases, effect sizes for condition favoured caffeine and ranged from 0.14 to 0.97. Mean increases in velocity and power in resistance exercise ranged from 0.02 to 0.08 m/s and 42 to 156 W, respectively. The number of performed repetitions increased by 1.2 and jump height by 0.9 cm. Increases in power in the Wingate test ranged from 31 to 75 W. We did not find significant group × condition interaction effect (p > 0.05) in any of the analyzed exercise outcomes. Additionally, there were no significant correlations (p > 0.05; r ranged from -0.29 to 0.32) between habitual caffeine intake and the absolute change in exercise performance. These results suggest that habitual caffeine intake might not moderate the ergogenic effects of acute caffeine supplementation on resistance exercise, jumping, and Wingate performance.

CYP1A2 genotype and acute effects of caffeine on resistance exercise, jumping, and sprinting performance

Background

It has been suggested that polymorphisms within CYP1A2 impact inter-individual variation in the response to caffeine. The purpose of this study was to explore the acute effects of caffeine on resistance exercise, jumping, and sprinting performance in a sample of resistance-trained men, and to examine the influence of genetic variation of CYP1A2 (rs762551) on the individual variation in responses to caffeine ingestion.

Methods

Twenty-two men were included as participants (AA homozygotes n = 13; C-allele carriers n = 9) and were tested after the ingestion of caffeine (3 mg/kg of body mass) and a placebo. Exercise performance was assessed with the following outcomes: (a) movement velocity and power output in the bench press exercise with loads of 25, 50, 75, and 90% of one-repetition maximum (1RM); (b) quality and quantity of performed repetitions in the bench press exercise performed to muscular failure with 85% 1RM; (c) vertical jump height in a countermovement jump test; and (d) power output in a Wingate test.

Results

Compared to placebo, caffeine ingestion enhanced: (a) movement velocity and power output across all loads (effect size [ES]: 0.20–0.61; p <  0.05 for all); (b) the quality and quantity of performed repetitions with 85% of 1RM (ES: 0.27–0.85; p <  0.001 for all); (c) vertical jump height (ES: 0.15; p = 0.017); and (d) power output in the Wingate test (ES: 0.33–0.44; p <  0.05 for all). We did not find a significant genotype × caffeine interaction effect (p-values ranged from 0.094 to 0.994) in any of the analyzed performance outcomes.

Conclusions

Resistance-trained men may experience acute improvements in resistance exercise, jumping, and sprinting performance following the ingestion of caffeine. The comparisons of the effects of caffeine on exercise performance between individuals with the AA genotype and AC/CC genotypes found no significant differences.

Trial registration

Australian New Zealand Clinical Trials Registry. ID: ACTRN12619000885190.

ADOR2A C Allele Carriers Exhibit Ergogenic Responses to Caffeine Supplementation

Caffeine’s ergogenic effects on exercise performance are generally explained by its ability to bind to adenosine receptors. ADORA2A is the gene that encodes A_2A subtypes of adenosine receptors. It has been suggested that ADORA2A gene polymorphisms may be responsible for the inter-individual variations in the effects of caffeine on exercise performance. In the only study that explored the influence of variation in ADORA2A—in this case, a common polymorphism (rs5751876)—on the ergogenic effects of caffeine on exercise performance, C allele carriers were identified as “non-responders” to caffeine. To explore if C allele carriers are true “non-responders” to the ergogenic effects of caffeine, in this randomized, double-blind study, we examined the acute effects of caffeine ingestion among a sample consisting exclusively of ADORA2A C allele carriers. Twenty resistance-trained men identified as ADORA2A C allele carriers (CC/CT genotype) were tested on two occasions, following the ingestion of caffeine (3 mg/kg) and a placebo. Exercise performance was evaluated with movement velocity, power output, and muscle endurance during the bench press exercise, countermovement jump height, and power output during a Wingate test. Out of the 25 analyzed variables, caffeine was ergogenic in 21 (effect size range: 0.14 to 0.96). In conclusion, ADORA2A (rs5751876) C allele carriers exhibited ergogenic responses to caffeine ingestion, with the magnitude of improvements similar to what was previously reported in the literature among samples that were not genotype-specific. Therefore, individuals with the CT/CC genotype may still consider supplementing with caffeine for acute improvements in performance.

Does the inclusion of ballistic exercises during warm-up enhance short distance running performance?

BACKGROUND

Warm-up is considered essential to optimize running performance, but little is known about the effect of specific warm-up tasks, specifically in the real competitive context. The current study aimed to verify the acute effects of a warm-up including ballistic exercises in 30m running performance. In addition, a second 30m trial was assessed to better understand the warm-up effects in training/competition.

METHODS

Twenty-two men (19.32±1.43 years-old) randomly completed the time-trials on separate days and after a typical warm-up (WU), a WU complemented with ballistic exercises (postactivation potentiation [PAP]) or no warm-up (NWU). Biomechanical, physiological and psychophysiological variables were assessed.

RESULTS

The participants were 1.9% faster in the first 30m sprint after WU compared with NWU, mainly increased performance in the first 15m (P=0.03, ES=0.48). WU resulted in greater stride length in the last 15m of the first sprint. PAP did not differ from NWU and WU, despite eight participants performed better after this warm-up.

CONCLUSIONS

These results highlight the positive effects of warm-up for sprinting, despite failed to evidence positive effects when ballistic exercises are included. In addition, the influence of warm-up in the running technique was highlighted by the changes in the running kinematics and a need for individualization of warm-up procedures.

Anodal and cathodal transcranial direct current stimulation can decrease force output of knee extensors during an intermittent MVC fatiguing task in young healthy male participants

Transcranial direct current stimulation (tDCS) has the capacity to enhance force output during a short-lasting maximal voluntary contraction (MVC) as well as during a long-lasting submaximal voluntary contraction until task failure. However, its effect on an intermittent maximal effort is not known. We hypothesized that anodal tDCS applied during or before a maximal fatigue task increases the amplitude of maximal voluntary contraction (aMVC) and voluntary activation (VA) in young healthy male participants. We measured VA, potentiated twitch at rest (Ptw), root mean square electromyogram (EMG), and aMVC during a fatiguing task that consisted of 35 × 5 s MVC of knee extensors and was performed during tDCS or 10 min after the end of tDCS (sham, anodal, or cathodal treatments). No effect of tDCS was detected on the first MVC but, when compared to sham tDCS, both anodal tDCS and cathodal tDCS reduced aMVC when tDCS was applied during the task (p < .001) and only anodal tDCS reduced aMVC when applied 10 min before the task (p = .03). The reductions in aMVC were accompanied by reductions in EMG of M. vastus lateralis for both tDCS treatments as well as in Ptw only during anodal tDCS and in VA only during cathodal tDCS. Both cathodal tDCS and anodal tDCS impaired force production during an intermittent fatiguing MVC task. The detrimental effects were stronger when tDCS was applied during the task. Here, cathodal and anodal tDCS specifically affected Ptw and VA indicating different underlying mechanisms.

The Role of Visual Feedback on Power Output During Intermittent Wingate Testing in Ice Hockey Players

Background: Visual feedback may help elicit peak performance during different types of strength and power testing, but its effect during the anaerobic Wingate test is unexplored. Therefore, the purpose of this study was to determine the effect of visual feedback on power output during a hockey-specific intermittent Wingate test (AnWT6x6) consisting of 6 stages of 6 s intervals with a 1:1 work-to-rest ratio. Methods: Thirty elite college-aged hockey players performed the AnWT6x6 with either constant (n = 15) visual feedback during all 6 stages (CVF) or restricted (n = 15) visual feedback (RVF) where feedback was shown only during the 2nd through 5th stages. Results: In the first stage, there were moderate-to-large effect sizes for absolute peak power (PP) output and PP relative to body mass and PP relative to fat-free mass. However, the remaining stages (2⁻6) displayed small or negligible effects. Conclusions: These data indicate that visual feedback may play a role in optimizing power output in a non-fatigued state (1st stage), but likely does not play a role in the presence of extreme neuromuscular fatigue (6th stage) during Wingate testing. To achieve the highest peak power, coaches and researchers could provide visual feedback during Wingate testing, as it may positively influence performance in the early stages of testing, but does not result in residual fatigue or negatively affect performance during subsequent stages.

Effects of work-matched moderate- and high-intensity warm-up on power output during 2-min supramaximal cycling

We tested the hypothesis that compared with a moderate-intensity warm-up, a work-matched high-intensity warm-up improves final-sprint power output during the last 30 s of a 120-s supramaximal exercise that mimics the final sprint during events such as the 800-m run, 1,500-m speed skate, or Keirin (cycling race). Nine active young males performed a 120-s supramaximal cycling exercise consisting of 90 s of constant-workload cycling at a workload that corresponds to 110% peak oxygen uptake (VO_2peak) followed by 30 s of maximal cycling. This exercise was preceded by 1) no warm-up (control), 2) a 10-min cycling warm-up at a workload of 40% VO_2peak (moderate-intensity), or 3) a 5-min cycling warm-up at a workload of 80% VO_2peak (high-intensity). Total work was matched between the two warm-up conditions. Both warm-ups increased 5-s peak (observed within 10 s at the beginning of maximal cycling) and 30-s mean power output during the final 30-s maximal cycling compared to no warm-up. Moreover, the high-intensity warm-up provided a greater peak (577±169 vs. 541±175 W, P=0.01) but not mean (482±109 vs. 470±135W, P=1.00) power output than the moderate-intensity warm-up. Both VO₂ during the 90-s constant workload cycling and the post-warm-up blood lactate concentration were higher following the high-intensity than moderate-intensity warm-up (all P≤0.05). We show that work-matched moderate- (~40% VO_2peak) and high- (~80% VO_2peak) intensity warm-ups both improve final sprint (~30 s) performance during the late stage of a 120-s supramaximal exercise bout, and that a high-intensity warm-up provides greater improvement of short-duration (<10 s) maximal sprinting performance.