Mark Chapman

Acute effects of distribution of rest between repetitions

The purpose of this study was to compare acute mechanical and metabolic effects of 2 sessions of resistance training equated by volume and total resting time but with different set configuration: sets to failure (FS) vs. distribution of rest between each repetition (NFS). 10 male judoists completed a session consisting of 3 sets to failure of parallel back squat with 4 repetitions at maximum load, and a rest of 3 min between the sets. At least 72 h later subjects developed the same volume, but total resting time was distributed among individual repetitions. Before and after sessions isometric force and mean propulsive velocity with load corresponding to maximum propulsive power were assessed. Results showed that in respect to FS, NFS showed an 18.94% (± 17.98) higher average mean propulsive velocity during session (0.42 ± 0.04 vs. 0.35 ± 0.08 m.s - 1; p=0.009), lower blood lactate concentration after session (maximum average value 1.52 ± 0.77 vs. 3.95 ± 1.82; session effect: p=0.001) and higher mean propulsive velocity with load corresponding to maximum propulsive power (mean propulsive velocity immediately after session 0.64 ± 0.09 vs. 0.59 ± 0.12 m.s - 1; session effect: p=0.019). These data show that distribution of rest in sessions equated for volume and total resting time determines differences in performance during sessions and mechanical or metabolic acute effects.

Immunoendocrine responses of male spinal cord injured athletes to 1-hour self-paced exercise: Pilot study

This study examined the effect of a 1 h, self-paced handcycling time trial on blood leukocytes, mucosal immunity, and markers of stress in paraplegic athletes. Nine male paraplegic athletes (spinal injury level thoracic 4-lumbar 2) performed 1 h of handcycling exercise on a standard 400 m athletics track. Heart rate (HR) was measured continuously during exercise, and a retrospective rating of perceived exertion (RPE) was obtained immediately after. Venous blood and saliva samples were collected immediately before exercise (Pre-Ex), after exercise (End-Ex), and 1 h postexercise (1-h Post). The athletes completed mean +/- standard error of mean 22.4 +/- 1.1 km cycling at HR 165 +/- 2 beats/min, RPE 15 +/- 1, and blood lactate 7.9 +/- 2.5 mmol/L. Total leukocytes increased 72% and neutrophils increased 74% End-Ex; both remained elevated at 1-h Post (both p < 0.05). Lymphocytes increased 53% and natural killer cells increased 175% End-Ex (both p < 0.05), but returned to near baseline levels 1-h Post. Increases (p < 0.05) were observed End-Ex in alpha-amylase activity (p < 0.05), which returned to baseline at 1-h Post, but there was no significant change in saliva flow rate, salivary immunoglobulin A, or cortisol. These data confirm that 1 h of handcycling exercise elevated circulating leukocytes but had a minimal effect on mucosal immunity. These changes appear to be associated with alpha-amylase rather than cortisol.

Effects of Three Different Conditioning Activity Volumes on the Optimal Recovery Time for Potentiation in College Athletes

Abstract Naclerio, F, Chapman, M, Larumbe-Zabala, E, Massey, B, Neil, A, and Triplett, TN. Effects of three different conditioning activity volumes on the optimal recovery time for potentiation in college athletes. J Strength Cond Res 29(9): 2579–2585, 2015—This study examined the effect of 3 postactivation potentiation (PAP) protocols, differentiated by volume and with controlled intensity, on the recovery time required to observe enhanced jumping performance in recreationally trained college athletes. Following a randomized controlled order, 11 participants, 7 men and 4 women (age 25.4 ± 2.1 years, height 176.2 ± 7.7 cm, body mass 77.6 ± 7.7 kg), performed a countermovement jump (CMJ) at baseline and at 15 seconds, 1, 2, 3, 5, 8, and 12 minutes after the 3 treatment conditions: low volume (LV, parallel squat [PS] with 80%, 1 repetition [rep]), moderate volume (MV, PS with 80%, 1 set of 3 reps), and high volume (HV, PS with 80%, 3 sets of 3 reps). Significantly lower CMJ heights were measured at 3 and 5 minutes from LV to HV (p = 0.048) and MV (p = 0.005) conditions, respectively. No significant differences were determined when comparing the 8 tested time points within each of the assessed volume protocols. However, effect size analysis indicated that higher CMJ performances displayed from 1 to 8 minutes with respect to both baseline and 15-second performance for MV (d = 0.91–3.18) and HV (d = 0.79) conditions. In conclusion, MV and HV protocols seem to be more effective to elicit potentiation compared with the LV. However, no relationship between the volume of conditioning activity (CA) and the optimal time point to obtain the maximum potentiation effect was determined. Strength and conditioning professionals are advised to analyze individual PAP responses in terms of the optimal recovery time with regard to different CA configurations.

Temporal and kinematic analysis of the rotational shot put technique

Kinematic data provide the biomechanist with valuable information to analyse athletic performance. The reduction and analysis involved in generating the data is often provided by commercially available hardware and software. To have confidence in any analysis, the system should first be validated. Several of these software systems have been evaluated previously for accuracy; however, no evaluation has been made of the SIMI Motion system (SIMI Reality Motion Systems, Unterschleissheim, Germany). The aim of this study was to determine the accuracy of the data derived using SIMI Motion. A calibration rig was constructed of four markers. Three markers were located in the horizontal plane, with one fixed at the origin and the other two located 400 mm from the origin at 908 to each other and free to rotate at 60 rev×min. The fourth marker was fixed at 300 mm in the horizontal and –18 mm in the vertical from the origin. A calibration frame (2.2, 1.9 and 1.6 m; Peak Performance Technologies Inc., Englewood, CO) was filmed in three dimensions at 50 Hz using two Sony DCR-TRV900E digital cameras. Within the calibration volume, the rig was filmed at two extreme positions and at two heights (ground level and elevated by 870 mm) for 6 s in a dynamic mode (i.e. the two markers rotating at 60 rev×min). In addition, the rig was filmed once at position A, located at ground level furthest away from the camera, while static. The four markers were manually digitized and analysed using SIMI Motion version 6.0. The data were smoothed using a second-order low-pass filter with a cut-off frequency of 3.475 Hz, determined using the equation recommended by Yu et al. (1999: Journal of Applied Biomechanics, 15, 318–329). Distances, angles and angular velocities were obtained for several fixed and variable measurements and the mean absolute errors were calculated. The results for the final 3 s of the dynamic mode data capture at position A were (criterion+mean absolute error): fixed distance, 400+7 mm; fixed angle, 90+28; angular velocity of the fixed angle, 0+0.33 rad×s; angular velocity of the rotating arm, 6.28+0.85 rad×s. The mean absolute error of 7 mm for the fixed distance compares favourably with the 12 mm reported by Ehara et al. (1997: Gait and Posture, 5, 251–255) for the APAS system (Ariel Dynamics Inc., Trabuco Canyon, CA) and the 18 mm for the Dynas 3D/h system (Shin Oosaka Shoukai, Osaka, Japan). However, this error is greater than the 4 mm reported for the Peak 5 system (Peak Performance Technologies Inc.). The mean absolute error of 28 compares favourably with the root mean square error of 2.18 reported by Richards (1999: Human Movement Science, 18, 589–602) for the APAS system. The mean absolute error is, however, not directly comparable, as it provides a predictably larger value than the root mean square error, depending on the number of samples used in the calculation of the latter. The data were less variable for the angular velocity of the fixed angle than for the angular velocity of the rotating arm. However, the angle definition used to calculate the angular velocity of the rotating arm produced maximum and minimum angles that subsequently resulted in changes in direction of the angular velocity. On removing four samples at the change of direction of the angular velocity, the mean absolute error of the angular velocity of the rotating arm was reduced to the same error as for the angular velocity of the fixed angle (that is, +0.85 to +0.33 rad×s). In summary, the accuracy of the linear and angular position data of the SIMI Motion system compares favourably with that of other similar manual digitizing systems. However, the results of the first derivative may magnify any errors and care should be taken when interpreting such values. In producing any derivative data, the analysis also emphasizes the importance of Journal of Sports Sciences, 2003, 21, 235–365Proprioceptive neuromuscular facilitation (PNF) stretching techniques are becoming more popular among athletes, since they provide (possibly only temporary) increases in joint range of movement compared with other methods. However, other effects – in particular the effects upon the proprioceptive system and its subsequent role in motor control – have not been recorded. The aim of this study was to establish if there are any significant changes in postural sway after the application of a lower limb PNF stretching session.The Raman spectra of the ammonia-borane complex, NH3BH3, have been investigated as a function of pressure up to 40 kbar. Vibrational modes involving the NH3 group show negative pressure dependences, supporting the existence of the dihydrogen bond, but the vibrations of the BH3 group have a positive dependence. Two transitions were observed in the solid phase under pressure, in contrast to the temperature behavior, where a single transition occurs. Factor group splitting occurs for the degenerate vibrations, and this allows the correct assignment of the observed vibrations.Optimal release variables (angle, velocity and height) in the shot put have been studied extensively. The importance of selected temporal, kinetic and kinematic variables in the glide technique have been reviewed comprehensively (Zatsiorsky, 1990: In Techniques in Athletics, edited G.P. Bruggeman and J.K. Ruhl. Koln: Deutsche Sporthochschule); however, there is very little data on the rotational shot put technique. The aim of this study was to establish whether there are any significant relationships between distance thrown and selected temporal and kinematic components of the rotational shot put technique.

Perceptual, Mechanical And Electromyographic Responses To Different Relative Loads In The Parallel Squat

Abstract Chapman, M, Larumbe-Zabala, E, Gosss-Sampson, M, Colpus, M, Triplett, NT, and Naclerio, F. Perceptual, mechanical, and electromyographic responses to different relative loads in the parallel squat. J Strength Cond Res 33(1): 8–16, 2019—The effectiveness of the OMNI-RES (0–10) Scale and the electromyographic signal for monitoring changes in the movement velocity were examined during a set to muscular failure using different percentages of 1 repetition maximum (1RM) in the parallel squat exercise (PSQ). Twelve men (26.3 ± 5.8 years) were evaluated on 8 separate days with 48 hours of rest between sessions. After determining the 1RM value, participants underwent 7 tests until achieving muscular failure with the following percentage ranges: 30 to <40%, 40 to <50%, 50 to <60%, 60 to <70%, 70 to <80%, 80 to <90%, and >90%. An optical rotary encoder measured mean accelerative velocity (MAV), and the OMNI-RES (0–10) Scale was used to express the rating of perceived exertion (RPE) after every repetition of each set. In addition, the normalized root mean square signal of the surface electromyography (N-EMG) was calculated for the vastus medialis muscle. The RPE expressed after the first repetition and when the maximum value of MAV was achieved along the sets was lower (p < 0.001, d > 0.8) than the RPE that corresponded to a 10% drop in MAV and at failure. In addition, the initial RPE was useful to distinguish different loading zones by anchoring the OMNI-RES value to the magnitude of the relative load (<60%, 60 to <70% or ⩽70% 1RM). Similar patterns were observed using the N-EMG. In conclusion, apart from differentiating between relative loads during a set to failure in the PSQ, the RPE and the N-EMG can both reflect changes associated with the initial, maximal, 10% drop in movement velocity and the muscular failure.

Use of the Rate of Perceived Exertion Scales in Resistance Training: A Comment on Mayo, Iglesias-Soler, and Fernández-Del-Olmo (2014):

Although perceived exertion scales were initially applied to endurance and cyclic exercises, they have been also used to monitor resistance training. The current article analyzes different criteria for the application of perception scales to resistance exercises. In addition, the proper use of perceived exertion to reflect the effect of different resistance training configurations including the fluctuation of velocity is also discussed. Furthermore, this paper also speaks to the issues of correct instructions and anchored scaling procedures, as well as how to use the perception scales to accurately select the loads, determine the number of repetitions per set, or to assess the effects of the training volume associated with different strength manifestations.