The Effect of a Short Practical Warm-up Protocol on Repeated Sprint Performance

Oksa

Clark

et al. 2018

The present study investigated whether increasing morning rectal temperatures (T) to evening levels, or increasing morning and evening T to an "optimal" level (38.5°C), resulting in increased muscle temperatures (T), would offset diurnal variation in repeated sprint (RS) performance in a causal manner. Twelve trained males underwent five sessions [age (mean ± SD) 21.0 ± 2.3 years, maximal oxygen consumption (V̇Omax) 60.0 ± 4.4 mL.kg min, height 1.79 ± 0.06 m, body mass 78.2 ± 11.8 kg]. These included control morning (M, 07:30 h) and evening (E, 17:30 h) sessions (5-min warm-up), and three further sessions consisting of a warm-up morning trial (M, in 39-40°C water) until T reached evening levels; two "optimal" trials in the morning and evening (M and E, in 39-40°C water) respectively, until T reached 38.5°C. All sessions included 3 × 3-s task-specific warm-up sprints, thereafter 10 × 3-s RS with 30-s recoveries were performed a non-motorised treadmill. T and T measurements were taken at the start of the protocol and following the warm-up periods. Values for T and T at rest were higher in the evening compared to morning values (0.48°C and 0.69°C, p < 0.0005). RS performance was lower (7.8-8.3%) in the M for distance covered (DC; p = 0.002), average power (AP; p = 0.029) and average velocity (AV; p = 0.002). Increasing T in the morning to evening values or optimal values (38.5°C) did not increase RS performance to evening levels (p = 1.000). However, increasing T in the evening to "optimal" level through a passive warm-up significantly reduced DC (p = 0.008), AP (p < 0.0005) and AV (p = 0.007) to values found in the M condition (6.0-6.9%). Diurnal variation in T and T is not wholly accountable for time-of-day oscillations in RS performance on a non-motorised treadmill; the exact mechanism(s) for a causal link between central temperature and human performance are still unclear and require more research.

Section: Discussionmentioning

confidence: 99%

Diurnal variation in repeated sprint performance cannot be offset when rectal and muscle temperatures are at optimal levels (38.5°C)

Oksa

Clark

et al. 2018

“…Relatively few studies have looked at precise modelling of pre-exercise temperature (by removing individuals from the active warming stimulus when the required Trec was reached) through an active warm-up (Edwards et al 2013;Pullinger et al 2018a). It has previously been established that the use of an active warm-up of standard duration (Sim et al 2009;Taylor et al 2013;Yaicharoen et al 2012), results in producing large variations in core and/or Tm within individuals. Consequently, the required core and/or Tm result in being under-or overshot.…”

Section: Discussionmentioning

confidence: 99%

Effects of an active warm-up on variation in bench press and back squat (upper and lower body measures)

Robertson

Oakley

et al. 2018

Effects of an active warm-up on variation in bench press and back squat (upper and lower body measures).http://researchonline.ljmu.ac.uk/id/eprint/12347/ Article LJMU has developed LJMU Research Online for users to access the research output of the University more effectively. Running title:Offsetting time-of-day variations in power. ABSTRACTThe present study investigated the magnitude of diurnal variation in back squat and bench press using the MuscleLab linear encoder over three different loads and assessed the benefit of an active warm-up to establish whether diurnal variation could be negated. Ten resistance-trained males underwent (mean ± SD: age 21.0 ± 1.3 yrs, height 1.77 ± 0.06 m and body mass 82.8 ± 14.9 kg) three sessions. These included control morning (M, 07:30 h) and evening (E, 17:30 h) sessions (5min standardised warm-up at 150 W, on a cycle ergometer), and one further session consisting of an extended active warm-up morning trial (ME, 07:30 h) until rectal temperature (Trec) reached previously recorded resting evening levels (at 150 W, on a cycle ergometer). All sessions included handgrip, followed by a defined programme of bench press (at 20, 40 and 60 kg) and back squat (at 30, 50 and 70 kg) exercises. A linear encoder was attached to an Olympic bar used for the exercises and average force (AF), peak velocity (PV) and time to peak velocity (tPV) were measured (MuscleLab software; MuscleLab Technology, Langesund, Norway) during the concentric phase of the movements. Values for Trec were higher in the E session compared to values in the M session (Δ 0.53°C, P < 0.0005). Following the extended active warm-up in the morning (ME), Trec and Tm values were no different to the E values (P < 0.05). Values for Tm were lower in the M compared to the E condition throughout (P < 0.05). There were time-of-day effects for hand grip with higher values of 6.49 % for left (P = 0.05) and 4.61 % for right hand (P = 0.002) in the E compared to the M. Daily variations were apparent for both bench press and back squat performance for AF (3.28 and 2.63 %), PV (13.64 and 11.50 %) and tPV (-16.97 and -14.12 %; where a negative number indicates a decrease in the variable from morning to evening). There was a main effect for load (P < 0.0005) such that AF and PV values were larger at higher masses on the bar than lower ones and tPV were smaller at lower masses on the bar than at higher masses for both bench press and back squat. We established that increasing Trec in the M to E values did not result in an increase of any measures related to bench press and back squat performance (P > 0.05) to increase from M to E levels. Therefore, MuscleLab linear encoder could detect meaningful differences between the morning and evening for all variables. However, the diurnal variation in bench press and back squat (measures of lower and upper body force and power output) are not explained time-of-day oscillations in Trec.

“…To the best of our knowledge, this is the first study to demonstrate these results, with precise modelling of pre-exercise temperature (by removing individuals from the warming or cooling stimulus when the required Trec or Tm was reached). Using a warm-up (active or passive) or cool-down of standard duration, as used by others [18,19,20,21], produces large variation in core and/or muscle temperatures within individuals, either resulting in over-or under-shooting the required value. It was observed that variation in the time taken to reach the required temperatures differed between participants and conditions (9:48±3:46 min:s for ME, 20:46±11:51 min:s for EMR, 6:55±6:10 min:s for EMM respectively.…”

Section: Discussionmentioning

confidence: 99%

Controlling rectal and muscle temperatures: Can we offset diurnal variation in repeated sprint performance?

Oksa

Iveson

et al. 2018

The present study investigated whether increasing morning rectal temperatures (T) to resting.evening levels, or decreasing evening T or muscle (T) temperatures to morning values, would influence repeated sprint (RS) performance in a causal manner. Twelve trained males underwent five sessions [age (mean ± SD) 21.8 ± 2.6 yr, peak oxygen uptake ([Formula: see text] peak) 60.6 ± 4.6 mL kg min, stature 1.78 ± 0.07 m and body mass 76.0 ± 6.3 kg]. These included a control morning (M, 07:30 h) and evening (E, 17:30 h) session (5-min warm-up), and three further sessions consisting of a warm-up morning trial (M, on a motorised treadmill) until T reached evening levels; and two cool-down evening trials (in 16-17°C water) until T (E) or T (E) values reached morning temperatures, respectively. All sessions included a 3 × 3-s task-specific warm-up followed by 10 × 3-s RS with 30-s recoveries performed on a non-motorised treadmill. T and T measurements were taken at the start of the protocol and following the warm-up or cool-down period. Values for T and T were higher in the evening compared to morning values (0.45°C and 0.57°C, P < 0.05). RS performance was lower in the M for distance covered (DC), average power (AP) and average velocity (AV) (9-10%, P < 0.05). Pre-cooling T and T in the evening reduced RS performance to levels observed in the morning (P < 0.05). However, an active warm-up resulted in no changes in morning RS performance. Diurnal variation in T and T is not wholly accountable for time-of-day oscillations in RS performance on a non-motorised treadmill; the exact mechanism(s) for a causal link between central temperature and human performance are still unclear and require more research.