Glen B. Deakin

The effect of short-term use of testosterone enanthate on muscular strength and power in healthy young men

Use of testosterone enanthate has been shown to significantly increase strength within 6–12 weeks of administration (2, 9), however, it is unclear if the ergogenic benefits are evident in less than 6 weeks. Testosterone enanthate is classified as a prohibited substance by the World Anti- Doping Agency (WADA) and its use may be detected by way of the urinary testosterone/epitestosterone (T/E) ratio (16). The two objectives of this study were to establish (a) if injection of 3.5 mg·kg-1 testosterone enanthate once per week could increase muscular strength and cycle sprint performance in 3–6 weeks; and (b) if the WADA-imposed urinary T/E ratio of 4:1 could identify all subjects being administered 3.5 mg·kg-1 testosterone enanthate. Sixteen healthy young men were match-paired and were assigned randomly in a double-blind manner to either a testosterone enanthate or a placebo group. All subjects performed a structured heavy resistance training program while receiving either testosterone enanthate (3.5 mg·kg-1) or saline injections once weekly for 6 weeks. One repetition maximum (1RM) strength measures and 10-second cycle sprint performance were monitored at the pre (week 0), mid (week 3), and post (week 6) time points. Body mass and the urinary T/E ratio were measured at the pre (week 0) and post (week 6) time points. When compared with baseline (pre), 1RM bench press strength and total work during the cycle sprint increased significantly at week 3 (p < 0.01) and week 6 (p < 0.01) in the testosterone enanthate group, but not in the placebo group. Body mass at week 6 was significantly greater than at baseline in the testosterone enanthate group (p < 0.01), but not in the placebo group. Despite the clear ergogenic effects of testosterone enanthate in as little as 3 weeks, 4 of the 9 subjects in the testosterone enanthate group (−44%) did not test positive to testosterone under current WADA urinary T/E ratio criteria.

The effects of strength training and endurance training order on running economy and performance

This study examined the acute effect of strength and endurance training sequence on running economy (RE) at 70% and 90% ventilatory threshold (VT) and on running time to exhaustion (TTE) at 110% VT the following day. Fourteen trained and moderately trained male runners performed strength training prior to running sessions (SR) and running prior to strength training sessions (RS) with each mode of training session separated by 6 h. RE tests were conducted at baseline (Base-RE) and the day following each sequence to examine cost of running (CR), TTE, and lower extremity kinematics. Maximal isometric knee extensor torque was measured prior to and following each training session and the RE tests. Results showed that CR at 70% and 90% VT for SR-RE (0.76 ± 0.10 and 0.77 ± 0.07 mL·kg(-0.75)·m(-1)) was significantly greater than Base-RE (0.72 ± 0.10 and 0.70 ± 0.11 mL·kg(-0.75)·m(-1)) and RS-RE (0.73 ± 0.09 and 0.72 ± 0.09 mL·kg(-0.75)·m(-1)) (P < 0.05). TTE was significantly less for SR-RE (237.8 ± 67.4 s) and RS-RE (275.3 ± 68.0 s) compared with Base-RE (335.4 ± 92.1 s) (P < 0.01). The torque during the SR sequence was significantly reduced for every time point following the strength training session (P < 0.05). However, no significant differences were found in torque following the running session (P > 0.05), although it was significantly reduced following the strength training session (P < 0.05) during the RS sequence. These findings show that running performance is impaired to a greater degree the day following the SR sequence compared with the RS sequence.

The acute effects intensity and volume of strength training on running performance

Abstract Strength training has been shown to cause acute detrimental effects on running performance. However, there is limited investigation on the effect of various strength training variables, whilst controlling eccentric contraction velocity, on running performance. The present study examined the effects of intensity and volume (i.e. whole body vs. lower body only) of strength training with slow eccentric contractions on running economy (RE) [i.e. below anaerobic threshold (AT)] and time-to-exhaustion (TTE) (i.e. above AT) 6 hours post. Fifteen trained and moderately endurance trained male runners undertook high-intensity whole body (HW), high-intensity lower body only (HL) and low-intensity whole body (LW) strength training sessions with slow eccentric contractions (i.e. 1:4 second concentric-to-eccentric contraction) in random order. Six hours following each strength training session, a RE test with TTE was conducted. The results showed that HW, HL and LW sessions had no effect on RE and that LW session had no effect on TTE (P≥0.05). However, HW and HL sessions significantly reduced TTE (P<0.05). These findings demonstrate that a 6-hour recovery period following HW, HL and LW sessions may minimize attenuation in endurance training performance below AT, although caution should be taken for endurance training sessions above AT amongst trained and moderately endurance trained runners.

The reliability of lower extremity and thoracic kinematics at various running speeds.

Whilst various studies have examined lower extremity joint kinematics during running, there is limited investigation on joint kinematics at steady-state running and at intensities close to exhaustion. Subsequently, the purpose of this study was to determine whether the reliability of kinematics in the lower extremity and thorax is affected by varying the running speeds during a running economy test. 14 trained and moderately trained runners undertook 2 running economy tests with each test incorporating 3 intensity stages: 70-, 90- and 110% of the second ventilatory threshold, respectively. The participants ran for 10 min during each of the first 2 stages and to exhaustion during the last stage. Kinematics of the ankle, knee, hip, pelvis and thorax were recorded using a 3-dimensional motion analysis system. Intra-class correlation coefficient (ICC), limits of agreement (LOA) and coefficient of variation (CV) were used to calculate reliability. The ICC, LOA and CV of the lower extremity and thoracic kinematic variables ranged from 0.33-0.97, 1.03-1.39 and 2.0-18.6, respectively. Whilst the reliability did vary between the kinematic variables, the majority of results showed minimal within-subject variation and moderate to high reliability. In conclusion, examining thoracic and lower extremity kinematics is useful in determining whether running kinematics is altered with varying running intensities.

Kinematic and electromyographic comparisons between chin-ups and lat-pull down exercises

The purpose of this study was to compare kinematics and muscle activity between chin-ups and lat-pull down exercises and between muscle groups during the two exercises. Normalized electromyography (EMG) of biceps brachii (BB), triceps brachii (TB), pectoralis major (PM), latissimus dorsi (LD), rectus abdominus (RA), and erector spinae (ES) and kinematics of back, shoulder, and seventh cervical vertebrae (C7) was analysed during chin-ups and lat-pull down exercises. Normalized EMG of BB and ES and kinematics of shoulder and C7 for chin-ups were greater than lat-pull down exercises during the concentric phase (p < 0.05). For the eccentric phase, RA during lat-pull down exercises was greater than chin-ups and the kinematics of C7 during chin-ups was greater than lat-pull down exercises (p < 0.05). For chin-ups, BB, LD, and ES were greater than PM during the concentric phase, whereas BB and LD were greater than TB, and LD was greater than RA during the eccentric phase (p < 0.05). For lat-pull down exercise, BB and LD were greater than PM, TB, and ES during the concentric phase, whereas LD was greater than PM, TB, and BB during the eccentric phase (p < 0.05). Subsequently, chin-ups appears to be a more functional exercise.

Acclimation Training Improves Endurance Cycling Performance in the Heat without Inducing Endotoxemia

Purpose: While the intention of endurance athletes undertaking short term heat training protocols is to rapidly gain meaningful physical adaption prior to competition in the heat, it is currently unclear whether or not this process also presents an overt, acute challenge to the immune system. The aim of this study was therefore to examine the effects of heat training on both endurance performance and biomarkers associated with inflammatory and immune system responses. Methods: Moderately-actively males (n = 24) were allocated randomly to either HOT (n = 8, 35°C, and 70% RH; NEUTRAL (n = 8, 20°C, and 45% RH); or a non-exercising control group, (CON, n = 8). Over the 18 day study HOT and NEUTRAL performed seven training sessions (40 min cycling at 55 of VO2 max) and all participants completed three heat stress tests (HST) at 35°C and 70% RH. The HST protocol comprised three × sub-maximal intervals followed by a 5 km time trial on a cycle ergometer. Serum samples were collected before and after each HST and analyzed for interleukin-6, immunoglobulin M and lipopolysaccharide. Results: Both HOT and NEUTRAL groups experienced substantial improvement to 5 km time trial performance (HOT −33 ± 20 s, p = 0.02, NEUTRAL −39 ± 18 s, p = 0.01) but only HOT were faster (−45 ± 25 s, and −12 s ± 7 s, p = 0.01) in HST3 compared to baseline and HST2. Interleukin-6 was elevated after exercise for all groups however there were no significant changes for immunoglobulin M or lipopolysaccharide. Conclusions: Short-term heat training enhances 5 km cycling time trial performance in moderately-fit subjects by ~6%, similar in magnitude to exercise training in neutral conditions.Three top-up training sessions yielded a further 3% improvement in performance for the HOT group. Furthermore, the heat training did not pose a substantial challenge to the immune system.

The comparison of cold-water immersion and cold air therapy on maximal cycling performance and recovery markers following strength exercises

This study examined the effects of cold-water immersion (CWI) and cold air therapy (CAT) on maximal cycling performance (i.e. anaerobic power) and markers of muscle damage following a strength training session. Twenty endurance-trained but strength-untrained male (n = 10) and female (n = 10) participants were randomised into either: CWI (15 min in 14 °C water to iliac crest) or CAT (15 min in 14 °C air) immediately following strength training (i.e. 3 sets of leg press, leg extensions and leg curls at 6 repetition maximum, respectively). Creatine kinase, muscle soreness and fatigue, isometric knee extensor and flexor torque and cycling anaerobic power were measured prior to, immediately after and at 24 (T24), 48 (T48) and 72 (T72) h post-strength exercises. No significant differences were found between treatments for any of the measured variables (p > 0.05). However, trends suggested recovery was greater in CWI than CAT for cycling anaerobic power at T24 (10% ± 2%, ES = 0.90), T48 (8% ± 2%, ES = 0.64) and T72 (8% ± 7%, ES = 0.76). The findings suggest the combination of hydrostatic pressure and cold temperature may be favourable for recovery from strength training rather than cold temperature alone.

The Acute Effect of Concurrent Training on Running Performance Over 6 Days

Purpose: This study examined the effects of strength training on alternating days and endurance training on consecutive days on running performance for 6 days. Methods: Sixteen male and 8 female moderately trained individuals were evenly assigned into concurrent-training (CCT) and strength-training (ST) groups. The CCT group undertook strength training on alternating days combined with endurance training on consecutive days for 6 days. One week later, the CCT group conducted 3 consecutive days of endurance training only to determine whether fatigue would be induced with endurance training alone (CCT-Con). Endurance training was undertaken to induce endurance-training stimulus and to measure the cost of running (CR), rating of perceived exertion (RPE), and time to exhaustion (TTE). The ST group undertook 3 strength-training sessions on alternating days. Maximal voluntary contraction (MVC), rating of muscle soreness (RMS), and rating of muscle fatigue (RMF) were collected prior to each strength and endurance session. Results: For the CCT group, small differences were primarily found in CR and RPE (ES = 0.17–0.41). However, moderate-to-large reductions were found for TTE and MVC (ES = 0.65–2.00), whereas large increases in RMS and RMF (ES = 1.23–2.49) were found prior to each strength- and endurance-training session. Small differences were found in MVC for the ST group (ES = 0.11) and during CCT-Con for the CCT group (ES = 0.15–0.31). Conclusion: Combining strength training on alternating days with endurance training on consecutive days impairs MVC and running performance at maximal effort and increases RMS and RMF over 6 days.

Reliability and validity of an incremental cadence cycle VO2max testing protocol for trained cyclists

Cycle tests for maximal oxygen uptake (VO2max) have traditionally used incremental resistance protocols (RP) at a constant cadence. The purpose of this study was to evaluate whether an incremental cadence protocol (CP) using a constant resistance relative to gross body mass was as reliable and valid in eliciting VO2max as RP in trained cyclists. Ten male recreational cyclists aged 25.2 ± 6.8 years completed two CP and one RP trials in a randomized order over a 3-week period. The CP started at a workload of 2.75 W per kg body mass, with the cadence increased by 10 rpm each minute from 70 rpm. The RP started from 125 W with workload increased 25 W each minute with a constant cadence of 90 rpm. The results showed no significant differences between the CP (mean of the two CP trials) and RP for peak VO2 (3.9 ± 0.6 vs. 4.0 ± 0.8 L·min−1), peak ventilation (140.5 ± 22.8 vs. 143.0 ± 27.1 L·min−1) and post-exercise blood lactate (11.4 ± 2.1 vs. 11.9 ± 1.6 mmol·L−1), while peak heart rate (183.9 ± 10.5 vs. 187.5 ± 11.4 beats·min−1) and peak workload (319.9 ± 60.2 vs. 375.1 ± 67.3 W) were significantly less for the CP than the RP. For the two CP trials, the intraclass correlation coefficient for test–retest reliability was 0.96, the technical error of measurement (TEM) was 0.17 L·min−1, and the relative TEM was 4.35%. The results indicate that the CP is equally effective in eliciting VO2max as the RP and is a reliable method of measuring VO2max in trained recreational cyclists.

Brain and cardiorespiratory responses to exercise in hot and thermoneutral conditions

The aim of this study was to test whether or not concurrent evaluations of brain (electroencephalography [EEG]) and cardiorespiratory responses to exercise are influenced by environmental conditions. 10 adult male participants performed a standardized incremental exercise test to exhaustion on a cycle ergometer in an environment controlled laboratory on 2 separate occasions, in a randomized order; one in a hot condition (34.5°C) and one in a thermoneutral condition (20°C). EEG, heart rate and expired air were collected throughout. EEG data were decontaminated for artefacts, log-transformed and expressed as aggregated alpha and beta power responses across electrodes reflecting the frontal cortex of the brain. Performance outcomes showed there was no difference in  V˙O2 peak across hot (42.5 ml/kg/min) and neutral (42.8 ml/kg/min) conditions, although ventilatory threshold (VT) occurred at a lower threshold (68%) in hot compared to neutral condition (74%) (p<0.05). EEG alpha and beta wave responses both demonstrated significant increases from baseline to VT (p<0.01). EEG beta-band activity was significantly elevated in the heat compared to the neutral condition. In conclusion, elevated EEG beta-band activity in response to incremental exercise in the heat suggests that beta-band activation and cortical awareness increases as exercise becomes increasingly intense.