Improve Cycling Time Trial Performance Research Articles

The Effect of Menthol Mouth Rinsing and Fluid Temperature on Male Cycling Performance in Thermoneutral Conditions.

The purpose of this study was to determine the effect of a menthol (MEN) mouth rinse (MR) on cycling time trial (TT) performance in thermoneutral conditions and to explore the impact of fluid temperature (cold water [CW] or thermoneutral water [TNW]) on MEN's effect on performance. Twelve trained male cyclists (VO2 peak, 61.4 ± 12.1 mL/kg/min) completed a cycling TT in thermoneutral conditions (21 ± 0.2 °C, 40 ± 0.6% relative humidity) with four different mouth rinses: (1) MEN + CW; (2) MEN + TNW; (3) CW; and (4) TNW. The time to complete the TT and the power output (W) were recorded. The ratings of perceived exertion (RPE, Borg 6-20), thermal sensation (TS), and thermal comfort (TC) were recorded prior to and throughout the TT. The core body temperature (Tc) and heart rate (HR) were recorded throughout. The TT duration was not significantly different between trials (MEN + TNW: 38:11 ± 12:48, MEN + CW: 37:21 ± 13:00, CW: 38:12 ± 13:54, TNW: 36:06 ± 14:12 mins:secs, p < 0.05). The mean trial power output did not significantly differ between conditions (>0.05). The Tc, HR, RPE, TS, and TC were not significantly different between trials (p > 0.05). The results suggest that a MEN MR with either CW or TNW does not significantly improve cycling TT performance in trained male cyclists compared to a CW or TNW MR in thermoneutral conditions.

Effects of mixed-method cooling between exercise bouts on thermoregulation and cycling time-trial performance in the heat

This study investigated the effects of mixed-method cooling during a short break between exercise bouts on thermoregulation and cycling time-trial (TT) performance in the heat. In a randomized crossover design, nine physically active men performed two 30-min cycling bouts that consisted of 25-min constant-paced cycling at 55% of maximal oxygen uptake followed by a 5-min TT in the heat (35 °C, 50% relative humidity). The two bouts were separated by a 15-min break. During the break, participants were assigned to a control trial (CON; 5 g kg−1 fluid ingestion at room temperature) or a mixed-method cooling trial (COOL; 5 g kg−1 ice slurry ingestion and cooling vest to cool the neck and torso). Physiological (rectal [Tre], forehead deep-tissue [Tdeep-head], mean skin [T‾sk], forehead skin [Thead], and neck skin [Tneck] temperatures, heart rate [HR], and skin blood flow [SkBF]) and perceptual data (ratings of perceived exertion [RPE], thermal comfort [TC], and thermal sensation [TS]) were measured. At the end of the 15-min break, Tdeep-head (−0.5 ± 0.2 °C, p < 0.001), T‾sk (−5.6 ± 3.1 °C, p = 0.001), Thead (−0.8 ± 0.4 °C, p = 0.001), Tneck (−9.8 ± 6.0 °C, p = 0.002), HR (−17 ± 6 bpm, p < 0.001), SkBF (−27.7 ± 13.9%, p = 0.002), TC (+2.6 ± 2.5, p = 0.024), and TS (−4.7 ± 2.5, p = 0.011) improved in COOL compared to CON. Reductions in T‾sk and Tneck were quickly lost (5 min) during the second exercise bout but Tdeep-head, Thead, and TS remained lower in COOL until the commencement of the second TT. Compared to CON, Tre (−0.2 ± 0.2 °C, p = 0.002) and RPE (−1.3 ± 0.9, p = 0.010) were lower in COOL during the second exercise bout. The reduction in mean power output at the second TT was attenuated in COOL (−13.9 ± 26.9 W) compared to CON (−29.3 ± 29.4 W; p = 0.015). In conclusion, the mixed-method cooling during a short break reduced physiological and perceptual strain and improved cycling TT performance.

Effects of Bilateral Dorsolateral Prefrontal Cortex High-Definition Transcranial Direct-Current Stimulation on Physiological and Performance Responses at Severe-Intensity Exercise Domain in Elite Road Cyclists.

To investigate the effects of bilateral dorsolateral prefrontal cortex high-definition transcranial direct-current stimulation (HD-tDCS) on physiological and performance responses during exercise at the upper limit of the severe-intensity exercise domain in elite-level road cyclists. Eleven elite-level road cyclists (VO2peak: 71.8 [3.1]mL·kg-1·min-1) underwent the HD-tDCS or SHAM condition in a double-blind, counterbalanced, and randomized order. After 20minutes of receiving either HD-tDCS on dorsolateral prefrontal cortex (F3 and F4) or SHAM stimulation, participants completed a 10-minute constant-load trial (CLT1) at 90% of the first ventilatory threshold and a 2-minute CLT (CLT2) at peak power output. Thereafter, they performed a simulated 2-km time trial (TT). Maximal oxygen uptake, respiratory exchange ratio, heart rate, and rating of perceived exertion were recorded during CLT1 and CLT2, whereas performance parameters were recorded during the TT. In 6 out of 11 cyclists, the total time to complete the TT was 3.0% faster in HD-tDCS compared to SHAM. Physiological and perceptual variables measured during CLT1 and CLT2 did not change between HD-tDCS and SHAM. HD-tDCS over the dorsolateral prefrontal cortex seemed to improve cycling TT performance within the upper limit of the severe-intensity exercise domain, suggesting that an upregulation of the prefrontal cortex could be critical even in this exercise intensity domain. However, the limited dimension and the high interindividual variability require further studies to test these putative ergogenic effects.

Four Weeks of Omega-3 Supplementation does not Improve Cycling Time Trial Performance in Trained Cyclists

This study examined whether omega-3 polyunsaturated fatty acid (n-3 PUFA) supplementation lowered the heart rate (HR), rating of perceived exertion (RPE) and oxygen uptake (V̇O₂) and accordingly improved cycling performance in a time trial.

Caffeine increases motor output entropy and performance in 4 km cycling time trial.

Caffeine improves cycling time trial performance through enhanced motor output and muscle recruitment. However, it is unknown if caffeine further increases power output entropy. To investigate the effects of caffeine effects on cycling time trial performance and motor output entropy (MOEn), nine cyclists (VO2MAX of 55 ± 6.1 mL.kg.-1min-1) performed a 4 km cycling time trial (TT4km) after caffeine and placebo ingestion in a counterbalanced order. Power output data were sampled at a 2 Hz frequency, thereafter entropy was estimated on a sliding-window fashion to generate a power output time series. A number of mixed models compared performance and motor output entropy between caffeine and placebo every 25% of the total TT4km distance. Caffeine ingestion improved power output by 8% (p = 0.003) and increased MOEn by 7% (p = 0.018). Cyclists adopted a U-shaped pacing strategy after caffeine ingestion. MOEn mirrored power output responses as an inverted U-shape MOEn during the time trial. Accordingly, a strong inverse correlation was observed between MOEn and power output responses over the last 25% of the TT4km (p < 0.001), regardless of the ingestion, likely reflecting the end spurt during this period (p = 0.016). Caffeine ingestion improved TT4km performance and motor output responses likely due to a greater power output entropy.

Tramadol Does Not Improve Performance or Impair Motor Function in Trained Cyclists.

To investigate the hypothesis that a therapeutic oral dose of Tramadol improves cycling time trial performance and compromises motor-cognitive performance in highly trained cyclists. Following two familiarization trials, 16 highly trained cyclists completed a preloaded time trial (1 h at 60% of peak power followed by a 15-km time trial) after ingestion of 100 mg Tramadol or placebo in a double-blind placebo-controlled counterbalanced crossover design separated by at least 4 d washout. Visuomotor tracking and math tasks were completed during the preload (n = 10) to evaluate effects on cognition and fine motor performance. Time trial mean power output (298 ± 42 W vs 294 ± 44 W) and performance (1474 ± 77 s vs 1483 ± 85 s) were similar with Tramadol and placebo treatment, respectively. In addition, there were no differences in perceived exertion, reported pain, blood pH, lactate, or bicarbonate concentrations across trials. Heart rate was higher (P < 0.001) during the Tramadol time trial (171 ± 8 bpm) compared with placebo (167 ± 9 bpm). None of the combined motor-cognitive tasks were impaired by Tramadol ingestion, in fact fine motor performance was slightly improved (P < 0.05) in the Tramadol trial compared with placebo. In highly trained cyclists, ingestion of 100 mg Tramadol does not improve performance in a 15-km cycling time trial that was completed after a 1-h preload at 60% peak power. Additionally, a therapeutic dose of Tramadol does not compromise complex motor-cognitive or simple fine motor performances.

Response.

Dear Editor-in-Chief, Heuberger and Cohen (1) address a potential concern regarding our recent conclusion that autologous blood transfusion (ABT) of approximately 135-mL packed red blood cells improves cycling time trial performance (2). The concern is related to our reported finding that total hemoglobin mass (tHb) was approximately 35 g lower in the ABT than placebo trial before transfusion. This result most likely reflects that our participants had not fully recovered from the phlebotomy performed 4 wk earlier. The question is whether this fact impacts our conclusion. We conclude that ABT of approximately 135 mL of packed red cells improves time-trial performance and this result cannot be questioned. However, it may be questioned whether the effect of ABT on performance is dependent on an initial difference in hemoglobin mass of 35 g. Although we cannot rule this out, it seems highly unlikely. Indeed, data from less-controlled studies of both moderately (3) and highly trained (4) subjects, where the initial hemoglobin mass must be expected to differ markedly (5), indicate that 900 to 1350 mL ABT improves performance. Thus, we argue that the valid concern related to initial tHb appears to be of little importance. Furthermore, Heuberger and Cohen postulate that time trial performance differs between ABT and placebo at the pretransfusion time point and argue that this may affect the conclusion. However, as described in our article, no significant difference in performance was apparent before transfusion. The significant time–treatment interaction only demonstrates that the effect of time may depend on the level of treatment. The subsequent post hoc analysis revealed that mean power output only increased significantly over time in ABT. Thus, the conclusion that approximately 135 mL ABT improves time trial performance compared with placebo is valid. Our recent study (2) was the first to investigate whether ABT of only approximately 135 mL packed red blood cells improves time trial performance in a relatively small number of participants. Thus, it is evident that the findings need to be validated, and we encourage further studies in the area. However, the conclusions drawn in our studies rest on solid scientific principles and are unlikely to be confounded by the difference in initial tHb. Jacob Bejder Andreas Breenfeldt Andersen Sara Amalie Solheim Nikolai B. Nordsborg Department of Nutrition, Exercise and Sports University of Copenhagen Copenhagen, DENMARK

The Threshold Ambient Temperature for the Use of Precooling to Improve Cycling Time-Trial Performance.

Cycling time-trial performance can be compromised by moderate to high ambient temperatures. It has become commonplace to implement precooling prior to competition to alleviate this performance decline. However, little is known about the ambient temperature threshold above which precooling becomes an effective strategy for enhancing endurance performance. The aim of this study was to investigate the effect of precooling in different environmental temperatures on time-trial (TT) performance. Trained cyclists completed 2 TTs with (COLD) and without (CON) precooling using an ensemble of ice vest and sleeves in ambient temperatures of 24°C, 27°C, and 35°C. TT performance was faster following COLD in both 35°C (6.2%) and 27°C (2.6%; both Ps < .05) but not 24°C (1.2%). Magnitude-based inferential statistics indicate that COLD was very likely beneficial to performance in 35°C, likely beneficial in 27°C, and possibly beneficial in 24°C. Mean power was 2.4%, 2.5%, and 5.6% higher following COLD and considered to be likely beneficial in 24°C and very likely beneficial in 27°C and 35°C. COLD reduced mean skin temperature throughout the warm-up and into the TT in all ambient temperatures (P < .05). Sweat loss was lower following COLD in 24°C and 27°C but not 35°C. There was no effect of COLD on gastrointestinal temperature at any point. Precooling with an ice vest and sleeves is likely to have a positive effect on TT performance at temperatures above 24°C, with a clear relationship between ambient temperature and the magnitude of effect of precooling.

Deception Improves Time Trial Performance in Well-trained Cyclists without Augmented Fatigue.

To investigate the effects of feedback, in the form of a virtual avatar paced at 100% and 102% of baseline performance, on neuromuscular fatigue after a 4-km cycling time trial (TT). We hypothesized that improved cycling performance would occur because of the participants exceeding a previously established critical threshold and experiencing greater neuromuscular fatigue. After familiarization, 10 well-trained cyclists performed a baseline 4-km TT without feedback (BASE), followed by two 4-km TT where they raced against an avatar (set at 100% accurate [ACC] and 102% deception [DEC] of baseline power output) in a randomized and counterbalanced order. Before and after each TT, neuromuscular fatigue was assessed using maximal isometric voluntary contractions (MVC) of the quadriceps, and supramaximal electrical stimulation of the femoral nerve, during and 2 s after MVCs to assess voluntary activation and potentiated twitch force. Blood lactate was taken pretrials and posttrials and RPE was taken throughout each TT. Time trial performance improved after deception of feedback compared with baseline performance (-5.8 s, P = 0.019). Blood lactate increased after DEC compared with BASE (+1.37 mmol·L, P = 0.019). Despite this, there was no difference in any measures of exercise-induced neuromuscular fatigue (P > 0.05). Similarly, RPE was not different between trials. Well-trained male cyclists can improve cycling TT performance when competing against an avatar increased to 102% of a previously established best effort. However, this improvement is not associated with a measurable augmentation of neuromuscular fatigue.

Dietary nitrate supplementation does not improve cycling time-trial performance in the heat

ABSTRACTThis investigation examined the effect of beetroot juice (BR) supplementation, a source of dietary nitrate (NO3−), on cycling time-trial (TT) performance and thermoregulation in the heat. In a double-blind, repeated-measures design, 12 male cyclists (age 26.6 ± 4.4 years, VO2peak 65.8 ± 5.5 mL.kg−1.min−1) completed four cycling TTs (14 kJ.kg−1) in hot (35°C, 48% relative humidity) and euthermic (21°C, 52%) conditions, following 3 days supplementation with BR (6.5 mmol NO3− for 2 days and 13 mmol NO3− on the final day), or NO3–depleted placebo (PLA). Salivary NO3− and nitrite, core (Tc) and mean skin temperature (Tsk) were measured. Salivary NO3− and nitrite increased significantly post-BR supplementation (p < 0.001). Average TT completion time (mm:ss) in hot conditions was 56:50 ± 05:08 with BR, compared with 58:30 ± 04:48 with PLA (p = 0.178). In euthermic conditions, average completion time was 53:09 ± 04:35 with BR, compared with 54:01 ± 04:05 with PLA (p = 0.380). The TT performance decreased (p < 0.001), and Tc (p < 0.001) and Tsk (p < 0.001) were higher in hot compared with euthermic conditions. In summary, BR supplementation has no significant effect on cycling TT performance in the heat.

Cross Acclimation between Heat and Hypoxia: Heat Acclimation Improves Cellular Tolerance and Exercise Performance in Acute Normobaric Hypoxia.

Background: The potential for cross acclimation between environmental stressors is not well understood. Thus, the aim of this investigation was to determine the effect of fixed-workload heat or hypoxic acclimation on cellular, physiological, and performance responses during post acclimation hypoxic exercise in humans.Method: Twenty-one males (age 22 ± 5 years; stature 1.76 ± 0.07 m; mass 71.8 ± 7.9 kg; O2 peak 51 ± 7 mL.kg−1.min−1) completed a cycling hypoxic stress test (HST) and self-paced 16.1 km time trial (TT) before (HST1, TT1), and after (HST2, TT2) a series of 10 daily 60 min training sessions (50% N O2 peak) in control (CON, n = 7; 18°C, 35% RH), hypoxic (HYP, n = 7; fraction of inspired oxygen = 0.14, 18°C, 35% RH), or hot (HOT, n = 7; 40°C, 25% RH) conditions.Results: TT performance in hypoxia was improved following both acclimation treatments, HYP (−3:16 ± 3:10 min:s; p = 0.0006) and HOT (−2:02 ± 1:02 min:s; p = 0.005), but unchanged after CON (+0:31 ± 1:42 min:s). Resting monocyte heat shock protein 72 (mHSP72) increased prior to HST2 in HOT (62 ± 46%) and HYP (58 ± 52%), but was unchanged after CON (9 ± 46%), leading to an attenuated mHSP72 response to hypoxic exercise in HOT and HYP HST2 compared to HST1 (p < 0.01). Changes in extracellular hypoxia-inducible factor 1-α followed a similar pattern to those of mHSP72. Physiological strain index (PSI) was attenuated in HOT (HST1 = 4.12 ± 0.58, HST2 = 3.60 ± 0.42; p = 0.007) as a result of a reduced HR (HST1 = 140 ± 14 b.min−1; HST2 131 ± 9 b.min−1 p = 0.0006) and Trectal (HST1 = 37.55 ± 0.18°C; HST2 37.45 ± 0.14°C; p = 0.018) during exercise. Whereas PSI did not change in HYP (HST1 = 4.82 ± 0.64, HST2 4.83 ± 0.63).Conclusion: Heat acclimation improved cellular and systemic physiological tolerance to steady state exercise in moderate hypoxia. Additionally we show, for the first time, that heat acclimation improved cycling time trial performance to a magnitude similar to that achieved by hypoxic acclimation.

Caffeinated nitric oxide-releasing lozenge improves cycling time trial performance.

Boosting nitric oxide production during exercise by various means has been found to improve exercise performance. We investigated the effects of a nitric oxide releasing lozenge with added caffeine (70 mg) on oxygen consumption during steady-state exercise and cycling time trial performance using a double-blinded randomized, crossover experimental design. 15 moderately trained cyclists (7 females and 8 males) were randomly assigned to ingest the caffeinated nitric oxide lozenge or placebo 5 min before exercise. Oxygen consumption and blood lactate were assessed at rest and at 50%, 65% and 75% maximal oxygen consumption. Exercise performance was assessed by time to complete a simulated 20.15 km cycling time-trial course. No significant treatment effects for oxygen consumption or blood lactate at rest or during steady-state exercise were observed. However, time-trial performance was improved by 2.1% (p<0.01) when participants consumed the nitric oxide lozenge (2,424±69 s) compared to placebo (2,476±78 s) and without a significant difference in rating of perceived exertion. These results suggest that acute supplementation with a caffeinated nitric oxide releasing lozenge may be a practical and effective means of improving aerobic exercise performance.

Acute whole body UVA irradiation combined with nitrate ingestion enhances time trial performance in trained cyclists

Dietary nitrate supplementation has been shown to increase nitric oxide (NO) metabolites, reduce blood pressure (BP) and enhance exercise performance. Acute exposure to ultraviolet (UV)-A light also increases NO bioavailability and reduces BP. We conducted a randomized, counterbalanced placebo-controlled trial to determine the effects of UV-A light alone and in combination with nitrate on the responses to sub-maximal steady-state exercise and time trial (TT) performance. Nine cyclists (VO2max 53.1 ± 4.4 ml/kg/min) completed five performance trials comprising 10 min submaximal steady-state cycling followed by a 16.1 km TT. Following a familiarization the final four trials were preceded, in random order, by either (1) Nitrate gels (NIT) + UV-A, (2) Placebo (PLA) + UV-A, (3) NIT + Sham light (SHAM) and (4) PLA + SHAM (control). The NIT gels (2 × 60 ml gels, ~8.1 mmol nitrate) or a low-nitrate PLA were ingested 2.5 h prior to the trial. The light exposure consisted of 20 J/cm2 whole body irradiation with either UV-A or SHAM light. Plasma nitrite was measured pre- and post-irradiation and VO2 was measured continuously during steady-state exercise. Plasma nitrite was higher for NIT + SHAM (geometric mean (95% CI), 332 (292–377) nM; P = 0.029) and NIT + UV-A (456 (312–666) nM; P = 0.014) compared to PLA + SHAM (215 (167–277) nM). Differences between PLA + SHAM and PLA + UV-A (282 (248–356) nM) were small and non-significant. During steady-state exercise VO2 was reduced following NIT + UVA (P = 0.034) and tended to be lower in NIT + SHAM (P = 0.086) but not PLA + UV-A (P = 0.381) compared to PLA + SHAM. Performance in the TT was significantly faster following NIT + UV-A (mean ± SD 1447 ± 41 s P = 0.005; d = 0.47), but not PLA + UV-A (1450 ± 40 s; d = 0.41) or NIT + SHAM (1455 ± 47 s; d = 0.28) compared to PLA + SHAM (1469 ± 52 s). These findings demonstrate that exposure to UV-A light alone does not alter the physiological responses to exercise or improve performance in a laboratory setting. A combination of UV-A and NIT, however, does improve cycling TT performance in this environment, which may be due to a larger increase in NO availability.

The effect of IMT on cycling time-trial performance at ~16°C (cool) and ~26°C (hot) temperatures

Objective: The purpose of this study was to investigate whether inspiratory muscle training (IMT) improved cycling time-trial (CTT) performance in both cool (~16°C) and hot (~26°C) environmental conditions in well-trained competitive male cyclists. Method: Twelve males were recruited (age: 39.3 ± 12.1 yrs.). Eight participants were assigned to the experimental (IMT) group (VO2max: 63.4 ± 7.6 ml • min-1 • kg-1; age: 41.4 ± 8.5 yrs.) and 4 to the control (CTRL) group (VO2max: 62.1 ±13.6 ml • min-1 • kg-1; age: 35.0 ± 18.1 yrs.). The IMT groups were prescribed an IMT training intervention and performance was assessed using a 10-km CTT in cool and hot conditions, pre- and post-intervention. IMT was performed using a pressure threshold loading (PTL) device set at 50% maximal inspiratory pressure (PImax) twice daily for 6-weeks. Results: CTT performance improved in the IMT group in the cool but not the hot. The IMT group went 1.17% faster in the cool (pre- vs. post-intervention: 940.38 ± 91.00 s vs. 929.38 ± 81.75 s) and 0.69% slower in the hot (927.63 ± 79.65 vs. 934.00 ± 74.73 s) (P>0.05). Post-intervention PImax increased in the IMT group both pre- and post-CTT by 25.90% and 22.01%; and 32.54% and 33.63%; respectively in the cool (P<0.05) and hot (P<0.05); the CTRL group observed no significant change. Discussion and Conclusions: IMT increased inspiratory muscle strength (IMS), attenuated inspiratory muscle fatigue (IMF) and improved CTT performance in the cool but not the hot condition. Heart rate increase (HRinc) was attenuated during the hot CTT and an increase in ear temperature (Tear) was counteracted during the cool CTT for a concurrent increase in physiological workload. In conclusion, IMT is a proven ergogenic aid for well-trained cyclists confirming that elite cyclists can still benefit from marginal gains.

Influence of Absolute versus relative L-arginine Dosage on 1 km and 16.1 km time trial performance in trained cyclists.

This investigation aimed to determine the effects of L-arginine supplementation on cycling time trial (TT) performance. Eight trained male cyclists performed 1 and 16.1km time trials on three occasions, control (CON), absolute (ABS) and relative (REL) loading. Participants consumed 500ml of water with either 6g (ABS), 0.15 g·kg-1 body mass (REL) of L-arginine or water (CON) 90min prior to testing. Time to completion, mean power output (Wmean) and post-exercise lactate (La) were recorded for each TT. Time to completion decreased non-significantly for 1 and 16.1km TT’s during ABS and REL trials compared to CON. Wmean was significantly different between CON and REL during 16.1 km TT (196.19 ± 32.40W and 215.81 ± 31.56W). Blood lactates was significantly different between CON and ABS for the 1 km TT (p = 0.04) (13.59 ± 1.21 mmol·L-1 and 12.38 ± 0.70 mmol·L-1, respectively) and between CON and ABS (p = 0.04) (9.11 ± 2.91mmol·L-1 and 7.64 ± 3.01mmol·L-1, respectively) and CON and REL (9.11 ± 2.91mmol·L-1 and 7.15 ± 2.96mmol·L-1, respectively) for 16.1km TT. These results indicate L-arginine supplementation does not significantly improve cycling TT performance, though there was a trend towards reduced time to completion and increased mean power output, and that relative doses appear more effective than absolute doses.

Inspiratory muscle warm-up does not improve cycling time-trial performance.

This study examined the effects of an active cycling warm-up, with and without the addition of an inspiratory muscle warm-up (IMW), on 10-km cycling time-trial performance. Ten cyclists (VO₂ = 65 ± 9 mL kg(-1) min(-1)) performed a habituation 10-km cycling time-trial and three further time-trials preceded by either no warm-up (CONT), a cycling-specific warm-up (CYC) comprising three consecutive 5-min bouts at powers corresponding to 70, 80, and 90% of the gas exchange threshold, or a cycling-specific warm-up preceded by an IMW (CYC + IMW) comprising two sets of 30 inspiratory efforts against a pressure-threshold load of 40% maximal inspiratory pressure (MIP). The cycling warm-up was followed by 2-min rest before the start of the time-trial. Time-trial performance times during CYC (14.75 ± 0.79 min) and CYC + IMW (14.70 ± 0.75 min) were not different, although both were faster than CONT (14.99 ± 0.90 min) (P < 0.05). Throughout the time-trial, physiological (minute ventilation, breathing pattern, pulmonary gas exchange, heart rate, blood lactate concentration and pH) and perceptual (limb discomfort and dyspnoea) responses were not different between CYC and CYC + IMW. Baseline MIP during CONT and CYC was 151 ± 31 and 156 ± 39 cmH₂O, respectively, and was unchanged following the time-trial. MIP increased by 8% after IMW (152 ± 27 vs. 164 ± 27 cmH2O, P < 0.05) and returned to baseline after the time-trial. Improvements in 10-km cycling time-trial performance following an active cycling warm-up were not magnified by the addition of an IMW. Therefore, an appropriately designed active whole-body warm-up does adequately prepare the inspiratory muscles for cycling time-trials lasting approximately 15 min.

Dietary nitrate supplementation improves time to fatigue in maximal cycling performance

Introduction: Previous research has shown improved exercise economy via reduced oxygen (O2) cost and increased performance during exercise with supplemental dietary nitrate intake. This supplementation has been shown to increase exercise time at VO2max power in cyclists as well as improved cycling time trial performance. Nitrate intake is believed to exert its effect on oxygen cost and performance by increasing nitric oxide bioavailability. This investigation examined the effect of varied nitrate concentration, contained in beetroot juice, on sub-maximal and maximal performance during cycling exercise.

Effect of an Energy Drink on Physical and Cognitive Performance in Trained Cyclists

Background: Caffeine and carbohydrates are used by consumers to increase exercise and certain aspects of cognitive performance. This study investigated the effectiveness of an energy drink (ED) containing caffeine to enhance cycling time-trial performance and cognitive performance at rest, during strenuous exercise, and after exercise. Methods: The experimental protocol was a double-blind, placebo-controlled, randomized, crossover design. The treatments were ED containing caffeine (160 mg), carbohydrate (54 g), taurine, and Panax ginseng, and a caffeine-free noncaloric placebo beverage (PLA). After a 12-hour calorie and caffeine abstention, exercise performance was measured by time to finish a simulated 35-km cycling time-trial course. Cognitive performance was measured by a Stroop Test, a tapping task, a reaction time task, and an executive function task consisting of both tapping and reaction time. Participants (n=15, seven women, eight men) were grouped as low-baseline (LO) or high-baseline (HI) since 5 of 15 participants (3 women, 2 men) had elevated baseline blood caffeine concentrations at both experimental trials. Results: Race performance improved by an average of 3% in both LO and HI groups when participants consumed ED compared with PLA. Although VO2 and heart rate were greater throughout the race for ED compared with PLA, there was no difference in perceived exertion between treatments. ED also increased taps per second in the tapping task before and after exercise. Conclusions: The results suggest that ED is an effective pre-exercise supplement that can improve cycling time-trial performance and possibly simple aspects of cognitive function even under elevated basal blood caffeine levels.

Opposition of Carbohydrate in a Mouth-Rinse Solution to the Detrimental Effect of Mouth Rinsing During Cycling Time Trials

Studies have reported that rinsing the mouth with a carbohydrate (CHO) solution improves cycling time-trial performance compared with rinsing with a placebo solution. However, no studies have compared the effect of mouth rinsing with a no-mouth-rinse control condition. The aim of this study was to compare the effects of a CHO mouth rinse with those of a placebo rinse and a no-rinse condition. Ten male cyclists completed three 1,000-kJ cycling time trials in a randomized, counterbalanced order. At every 12.5% of the time trial completed, participants were required to rinse their mouths for 5 s with either a 6.4% maltodextrin solution (CHO), water (WA), or no solution (CON). Heart rate and ratings of perceived exertion (RPE) were recorded every 25% of the time trial completed. Time to completion was faster in both CHO (65.7 ± 11.07 min) and CON (67.6 ± 12.68 min) than in WA (69.4 ± 13.81 min; p = .013 and p = .042, respectively). The difference between CHO and CON approached significance (p = .086). There were no differences in heart rate or RPE between any conditions. In summary, repeated mouth rinsing with water results in decreased performance relative to not rinsing at all. Adding CHO to the rinse solution appears to oppose this fall in performance, possibly providing additional benefits to performance compared with not rinsing the mouth at all. This brings into question the magnitude of the effect of CHO mouth rinsing reported in previous studies that did not include a no-rinse condition.

Dietary nitrate – a slow train coming

Dietary nitrate – a slow train coming