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

Effects of high-intensity inspiratory muscle warm-up on inspiratory muscle strength and accessory inspiratory muscle activity

This study aimed to determine the effects of work-matched moderate-intensity and high-intensity inspiratory muscle warm-up (IMW) on inspiratory muscle strength and accessory inspiratory muscle activity. Eleven healthy men performed three IMWs at different intensities, namely, placebo, moderate-intensity, and high-intensity, set, respectively, at 15%, 40%, and 80% of maximal inspiratory mouth pressure (MIP). MIP was measured before and after IMW. Electromyography (EMG) was recorded for the sternocleidomastoid muscle (SCM) and intercostal muscles (IC) during IMW. MIP increased significantly in the moderate-intensity condition (104.2 ± 5.1%, p<0.05) and high-intensity condition (106.5 ± 6.2%, p<0.01) after IMW. The EMG amplitudes of the SCM and IC during IMW were significantly higher in the order of high-intensity, moderate-intensity, and placebo conditions. There was a significant correlation between changes in MIP and EMG amplitude of the SCM (r=0.60, p<0.01) and IC (r=0.47, p<0.01) during IMW. These findings suggest that high-intensity IMW increases neuromuscular activity in the accessory inspiratory muscles, which may improve inspiratory muscle strength.

A modified formula using energy system contributions to calculate pure maximal rate of lactate accumulation during a maximal sprint cycling test

Purpose: This study aimed at comparing previous calculating formulas of maximal lactate accumulation rate ( ν La.max) and a modified formula of pure ν La.max (P ν La.max) during a 15-s all-out sprint cycling test (ASCT) to analyze their relationships. Methods: Thirty male national-level track cyclists participated in this study (n = 30) and performed a 15-s ASCT. The anaerobic power output (Wpeak and Wmean), oxygen uptake, and blood lactate concentrations (La-) were measured. These parameters were used for different calculations of ν La.max and three energy contributions (phosphagen, W PCr; glycolytic, W Gly; and oxidative, W Oxi). The P ν La.max calculation considered delta La-, time until Wpeak (tPCr-peak), and the time contributed by the oxidative system (tOxi). Other ν La.max levels without tOxi were calculated using decreasing time by 3.5% from Wpeak (tPCr -3.5%) and tPCr-peak. Results: The absolute and relative W PCr were higher than W Gly and W Oxi (p < 0.0001, respectively), and the absolute and relative W Gly were significantly higher than W Oxi (p < 0.0001, respectively); ν La.max (tPCr -3.5%) was significantly higher than P ν La.max and ν La.max (tPCr-peak), while ν La.max (tPCr-peak) was lower than P ν La.max (p < 0.0001, respectively). P ν La.max and ν La.max (tPCr-peak) were highly correlated (r = 0.99; R 2 = 0.98). This correlation was higher than the relationship between P ν La.max and ν La.max (tPCr -3.5%) (r = 0.87; R 2 = 0.77). ν La.max (tPCr-peak), P ν La.max, and ν La.max (tPCr -3.5%) were found to correlate with absolute Wmean and W Gly. Conclusion: P ν La.max as a modified calculation of ν La.max provides more detailed insights into the inter-individual differences in energy and glycolytic metabolism than ν La.max (tPCr-peak) and ν La.max (tPCr -3.5%). Because W Oxi and W PCr can differ remarkably between athletes, implementing their values in P ν La.max can establish more optimized individual profiling for elite track cyclists.

Identifying the Optimal Arm Priming Exercise Intensity to Improve Maximal Leg Sprint Cycling Performance

Priming exercises improve subsequent motor performance; however, their effectiveness may depend on the workload and involved body areas. The present study aimed to estimate the effects of leg and arm priming exercises performed at different intensities on maximal sprint cycling performance. Fourteen competitive male speed-skaters visited a lab eight times, where they underwent a body composition measurement, two V̇O_2max measurements (leg and arm ergometers), and five sprint cycling sessions after different priming exercise conditions. The five priming exercise conditions included 10-minute rest (Control); 10-minute arm ergometer exercise at 20% V̇O_2max (Arm 20%); 10-minute arm ergometer exercise at 70% V̇O_2max (Arm 70%); 1-min maximal arm ergometer exercise at 140% V̇O_2max (Arm 140%); and 10-min leg ergometer exercise at 70% V̇O_2max (Leg 70%). Power outputs of 60-s maximal sprint cycling, blood lactate concentration, heart rate, muscle and skin surface temperature, and rating of perceived exertion were compared between the priming conditions at different measurement points. Our results showed that the Leg 70% was the optimal priming exercise among our experimental conditions. Priming exercise with the Arm 70% also tended to improve subsequent motor performance, while Arm 20% and Arm 140% did not. Mild elevation in blood lactate concentration by arm priming exercise may improve the performance of high-intensity exercise.

The Effect of Lower Body Anaerobic Pre-Loading on Upper Body Ergometer Time Trial Performance

Pre-competitive conditioning has become a substantial part of successful performance. In addition to temperature changes, a metabolic conditioning can have a significant effect on the outcome, although the right dosage of such a method remains unclear. The main goal of the investigation was to measure how a lower body high-intensity anaerobic cycling pre-load exercise (HIE) of 25 s affects cardiorespiratory and metabolic responses in subsequent upper body performance. Thirteen well-trained college-level male cross-country skiers (18.1 ± 2.9 years; 70.8 ± 7.6 kg; 180.6 ± 4.7 cm; 15.5 ± 3.5% body fat) participated in the study. The athletes performed a 1000-m maximal double-poling upper body ergometer time trial performance test (TT) twice. One TT was preceded by a conventional low intensity warm-up (TT_low) while additional HIE cycling was performed 9 min before the other TT (TT_high). Maximal double-poling performance after the TT_low (225.1 ± 17.6 s) was similar (p > 0.05) to the TT_high (226.1 ± 15.7 s). Net blood lactate (La) increase (delta from end of TT minus start) from the start to the end of the TT_low was 10.5 ± 2.2 mmol L⁻¹ and 6.5 ± 3.4 mmol L⁻¹ in TT_high (p < 0.05). La net changes during recovery were similar for both protocols, remaining 13.5% higher in TT_high group even 6 min after the maximal test. VCO₂ was lower (p < 0.05) during the last 400-m split in TT_high, however during the other splits no differences were found (p < 0.05). Respiratory exchange ratio (RER) was significantly lower in TT_high in the third, fourth and the fifth 200 m split. Participants individual pacing strategies showed high relation (p < 0.05) between slower start and faster performance. In conclusion, anaerobic metabolic pre-conditioning leg exercise significantly reduced net-La increase, but all-out upper body performance was similar in both conditions. The pre-conditioning method may have some potential but needs to be combined with a pacing strategy different from the usual warm-up procedure.

High-Intensity Warm-Up Increases Anaerobic Energy Contribution during 100-m Sprint

Simple Summary

Certain exercise performances or movements cause sudden changes (or increases) in metabolic response. Track and field running events that require explosive energy in the shortest time, such as a 100-m sprint, need an immediate energy supply. Referring to the relevant studies to date, metabolic responses to submaximal exercise have been well documented, while information on the metabolic responses of short-term sprint performance is relatively insufficient. In this regard, based on the evidence that the human body relies on anaerobic energy metabolism during intense, short-term exercise, we investigated anaerobic energy contributions following the acute effect of a high-intensity warm-up during a 100 m-sprint. The main finding of our study revealed that a high-intensity warm-up (HIW) increases the contribution of the anaerobic system, probably by activating key regulatory enzymes related to anaerobic energy metabolism, compared to a low-intensity warm-up, for a 100-m sprint. Therefore, an HIW is effective in increasing anaerobic energy contribution during a 100-m sprint, which can be a useful strategy for coaches and athletes in the field.

Abstract

This study aimed to evaluate the effects of warm-up intensity on energetic contribution and performance during a 100-m sprint. Ten young male sprinters performed 100-m sprints following both a high-intensity warm-up (HIW) and a low-intensity warm-up (LIW). Both the HIW and LIW were included in common baseline warm-ups and interventional warm-ups (eight 60-m runs, HIW; 60 to 95%, LIW; 40% alone). Blood lactate concentration [La⁻], time trial, and oxygen uptake (VO₂) were measured. The different energy system contribution was calculated by using physiological variables. [La⁻¹]_Max following HIW was significantly higher than in LIW (11.86 ± 2.52 vs. 9.24 ± 1.61 mmol·L⁻¹; p < 0.01, respectively). The 100-m sprint time trial was not significantly different between HIW and LIW (11.83 ± 0.57 vs. 12.10 ± 0.63 s; p > 0.05, respectively). The relative (%) phosphagen system contribution was higher in the HIW compared to the LIW (70 vs. 61%; p < 0.01, respectively). These results indicate that an HIW increases phosphagen and glycolytic system contributions as compared to an LIW for the 100-m sprint. Furthermore, an HIW prior to short-term intense exercise has no effect on a 100-m sprint time trial; however, it tends to improve times (decreased 100-m time trial; −0.27 s in HIW vs. LIW).

A warm-up performed with proper-weight sandbags on the leg improves the speed and RPE performance of 100 m sprint in collegiate male sprinters

BACKGROUND

Muscle performance can be notably improved following a preloading maximal or near maximal stimulus due to the induction of postactivation potentiation, but the success of a preloading exercise in generating a postactivation potentiation response depends on the balance between fatigue and potentiation. However, the optimal warm-up strategy for sprint runners before a match may be not well established until now.

METHODS

Fifteen well-trained male sprint runners performed four different warm-up protocols: warm-up with 0% body mass; warm-up with 2% body mass; warm-up with 4% body mass; warm-up with 8% body mass. The weight-bearing sandbag was tied about 3~5 cm above each ankle joint. During the 100-meter test, the time and rating of perceived exertion (RPE) in the first 30 meters, time in the first 60 meters, and time in the 100 meters were recorded, respectively. Two-high-speed digital video cameras were separately set in the sagittal planes on the left side of a line drawn at a distance of 30 m and 60 m from the start line to record the sprint motion.

RESULTS

A warm-up performed with a sandbag weighted 4% of body mass could significantly improve the time and the RPE score of 100 m sprint by improving average velocity, stride frequency, average stride length, and average accelerated velocity during the sections of 0~30 m, 30~60 m and 60~100 m. This positive effect was better than that of 2% body-weigh effect. However, a warm-up performed with a sandbag weighted 8% of body mass had no significant influence on the performance of a 100 m sprint.

CONCLUSIONS

Current results indicated that a warm-up performed with proper-weight(4% body mass) sandbags on the leg was beneficial to the improvement of 100 m sprint performance, and the mechanism might be that it effectively activated the main muscles and neuromuscular regulation of running and produced a better postactivation potentiation.

Sigmoidal VO2 on-kinetics: A new pattern in VO2 responses at the lower district of extreme exercise domain

The aim of the study was to analyse the VO₂ on-kinetics belonging to the work rates within the lower district of extreme exercise domain. Maximal O₂ utilisation and peak power outputs of eight well-trained cyclists were revealed by multisession trails. Critical threshold (CT) as the lower boundary of severe domain and aerobic limit power (ALP) as the upper boundary of severe domain were determined by multisession constant-load exercises. VO₂ on-kinetics over time were best fitted by multicomponent exponential models described by an initial concave-up response known as cardio-dynamic phase (τ = 18.2 ± 2.88 s; a = 1.56 ± 0.39 L·min^-1) before a primary concave-up phase (τ = 35.4 ± 12.4 s; a = 1.53 ± 0.36 L·min^-1), and then a slow component in two of the participants (τ = 80.8 ± 37 s; a = 0.47 ± 0.05 L·min^-1) or without a slow component in six of the participants during exercises performed at 50 W above the CT (R²≥0.96; SEE ≤ 0.24; p < 0.001). However, VO₂ on-kinetics over time belonging to exercises performed at 50 W above the ALP were best fitted by sigmoidal model (R²≥0.98; SEE ≤ 0.14; p < 0.001) in comparison with linear (R² = 0.37-0.66; SEE = 0.46-0.64; p < 0.01), or exponential functions (p> 0.05). Indeed, during those exercises, a short period of convex-up response (τ = 16.8 ± 3.1 s; a = 1.72 ± 0.39 L·min^-1) was determined just before a concave-up primary phase in VO₂ over time (τ = 24.6 ± 5.86 s; a = 1.31 ± 0.20 L·min^-1). It was shown that multicomponent exponential trend in VO₂ transformed into a sigmoidal shape, once the work rate exceeded the upper boundary of severe exercise domain.

Effects of work-matched supramaximal intermittent vs. submaximal constant-workload warm-up on all-out effort power output at the end of 2 minutes of maximal cycling

We tested the hypothesis that work-matched supramaximal intermittent warm-up improves final-sprint power output to a greater degree than submaximal constant-intensity warm-up during the last 30 s of a 120-s supramaximal exercise simulating the final sprint during sports events lasting approximately 2 min. Ten male middle-distance runners performed a 120-s supramaximal cycling exercise consisting of 90 s of constant-workload cycling at a workload corresponding to 110% maximal oxygen uptake (VO_2max) followed by 30 s of maximal-effort cycling. This exercise was preceded by 1) no warm-up (Control), 2) a constant-workload cycling warm-up at a workload of 60%VO_2max for 6 min and 40 s, or 3) a supramaximal intermittent cycling warm-up for 6 min and 40 s consisting of 5 sets of 65 s of cycling at a workload of 46%VO_2max + 15 s of supramaximal cycling at a workload of 120%VO_2max. By design, total work was matched between the two warm-up conditions. Supramaximal intermittent and submaximal constant-workload warm-ups similarly increased 5-s peak (590 ± 191 vs. 604 ± 215W, P = 0.41) and 30-s mean (495 ± 137 vs. 503 ± 154W, P = 0.48) power output during the final 30-s maximal-effort cycling as compared to the no warm-up condition (5-s peak: 471 ± 165W; 30-s mean: 398 ± 117W). VO₂ during the 120-s supramaximal cycling was similarly increased by the two warm-ups as compared to no-warm up (P ≤ 0.05). These findings show that work-matched supramaximal intermittent and submaximal constant-workload warm-ups improve final sprint (∼30 s) performance to similar extents during the late stage of a 120-s supramaximal exercise bout.