Maximal mechanical power during a taper in elite swimmers

INTRODUCTION: Insight regarding the fluctuations in neuromuscular function among athletes during a taper is lacking. PURPOSE: This study examined the time course of changes in maximal mechanical power (Pmax), torque at power maximum (T), velocity at power maximum (V), and swim performance (m x s(-1)) that occur during the taper. METHODS: Using an arm ergometer with inertial loading, measurements were made during the week prior to the initiation of the taper (high volume, HV), during the 2- to 3-wk period of the taper (taper), and during the week of peak competition (peak) in 24 male competitive collegiate swimmers. Subjects were divided into groups that tapered to peak performance at either the conference (CONF, N = 13) or national (NAT, N = 11) championship competitions. RESULTS: CONF increased Pmax 10.2% (P < 0.01) and swim performance 4.4% (P < 0.001). NAT increased Pmax by 11.6% (P < 0.01), T by 7.4% (P < 0.02), and swim performance by 4.7% (P < 0.001). Pmax displayed a biphasic increase with approximately 50, 5, and 45% of the total increase occurring during the first, second, and third weeks of the taper, respectively. The biphasic response was the most common response among individual swimmers. Swimming performance was significantly correlated to both power and torque (P < 0.05). CONCLUSION: In summary, maximal arm power measured using inertial load ergometry increased largely during the first and third weeks after training volume was tapered for peak performance in elite collegiate swimmers.     

Effects of taper on swim power, stroke distance, and performance.

Competitive swimmers progressively reduce training volume or "taper" prior to an important competition in an effort to improve performance capabilities. The purpose of the current study was to determine the effects of taper upon factors associated with swim performance. Twelve intercollegiate swimmers were tested before and after taper in preparation for their season-ending meet. Power during a tethered sprint swim increased significantly (P < 0.05) by approximately 5% with taper. No significant changes occurred in distance per stroke, oxygen consumption, and post-exercise blood lactate level during a 182.9-m submaximal swim with taper. Five swimmers were additionally tested after shaving exposed body hair upon completion of taper. Swim power did not increase further with hair removal. In contrast, shaving significantly increased distance per stroke (P < 0.05) by approximately 5%. These data indicate that reduced training specifically improves swim power; however, removing exposed body hair after taper may additionally enhance performance capabilities by increasing distance per stroke.     

Volume vs. intensity in the training of competitive swimmers

The present study aimed at comparing a high-volume, low-intensity vs. low-volume, high-intensity swim training. In a randomized cross-over design, 10 competitive swimmers performed two different 4-week training periods, each followed by an identical taper week. One training period was characterized by a high-training volume (HVT) whereas high-intensity training was prevalent during the other program (HIT). Before, after two and four weeks and after the taper week subjects performed psychometric and performance testing: profile of mood states (POMS), incremental swimming test (determination of individual anaerobic threshold, IAT), 100 m and 400 m. A small significant increase in IAT was observed after taper periods compared to pre-training (+ 0.01 m/s; p = 0.01). Maximal 100-m and 400-m times were not significantly affected by training. The POMS subscore of "vigor" decreased slightly after both training periods (p = 0.06). None of the investigated parameters showed a significant interaction between test-time and training type (p > 0.13). Nearly all (83 %) subjects swam personal best times during the 3 months after each training cycle. It is concluded that, for a period of 4 weeks, high-training volumes have no advantage compared to high-intensity training of lower volume.     

5‐week block periodization increases aerobic power in elite cross‐country skiers

The purpose of this study was to compare the effect of two different methods of organizing endurance training in elite cross‐country skiers approaching the competition period. During the 5‐week intervention period, one group performed block periodization (BP; n = 10) with 5 and 3 high‐intensity sessions (HIT) during the first and third training week. One HIT was performed during the remaining weeks in BP, while the group performing traditional training organization (TRAD, n = 9) performed two weekly HIT except during the third week where they performed three HIT. HIT were interspersed with low‐intensity training (LIT) and both groups performed similar total amount of both HIT and LIT during the intervention. BP achieved a larger relative increase in peak power output and power output at a blood lactate concentration of 4 mmol/L than TRAD (4 ± 4 vs ?3 ± 6% and 11 ± 10 vs 2 ± 4%, respectively, both P < 0.01). BP also increased maximal oxygen uptake by 2 ± 2% (P < 0.05), while no changes occurred in TRAD. The effect sizes of the relative improvement in these measurements revealed moderate effects of BP vs TRAD training. The present study suggests that block periodization of endurance training have superior effects on several endurance and performance indices compared with traditional organization.     

Effects of 12 weeks of block periodization on performance and performance indices in well‐trained cyclists

The purpose of this study was to compare the effects of two different methods of organizing endurance training in trained cyclists during a 12‐week preparation period. One group of cyclists performed block periodization (BP; n = 8), wherein every fourth week constituted five sessions of high‐intensity aerobic training (HIT), followed by 3 weeks of one HIT session. Another group performed a more traditional organization (TRAD; n = 7), with 12 weeks of two weekly HIT sessions. The HIT was interspersed with low‐intensity training (LIT) so that similar total volumes of both HIT and LIT were performed in the two groups. BP achieved a larger relative improvement in VO_2max than TRAD (8.8 ± 5.9% vs 3.7 ± 2.9%, respectively, P < 0.05) and a tendency toward larger increase in power output at 2 mmol/L [la^?] (22 ± 14% vs 10 ± 7%, respectively, P = 0.054). Mean effect size (ES) of the relative improvement in VO_2max, power output at 2 mmol/L [la^?], hemoglobin mass, and mean power output during 40‐min all‐out trial revealed moderate superior effects of BP compared with TRAD training (ES range was 0.62–1.12). The present study suggests that BP of endurance training has superior effects on several endurance and performance indices compared with TRAD.     

Heart rate-perceived exertion relationship during training and taper

BACKGROUND: Examine the heart rate-perceived exertion (HR-RPE) relationship under conditions of high-intensity training and taper. METHODS: Experimental design and participants: prospective with collegiate cyclists (n=11) completed six weeks of high-intensity interval training, followed by a one-week taper. Interventions: participants completed a high-intensity training regimen along with graded exercise tests (GXT) throughout the training and the taper. Measures: heart rates (HR) and ratings of perceived exertion (RPE) were recorded following each stage of the GXTs. Scores on GXTs were also recorded. RESULTS:. The HR-RPE relationship during GXTs changed over the course of the training with greater RPEs for a given HR at the end of the training compared to the beginning. The most powerful predictors of the performance response to the taper were training induced changes in the HR-RPE relationship and decreases in HR for a given power output. Those individuals who reported higher RPEs for lower HRs were more likely to have better performance responses to taper (r=0.72) as were those who had larger changes in the HR-power output relationship (r=0.76). CONCLUSIONS: These results indicate that changes in the HR-RPE relationship during high-intensity training may be used to monitor the magnitude of overreaching that is necessary for a positive response to a taper. For coaches and athletes, the HR-RPE ratio may be a practical measure for monitoring an aspect of fatigue associated with high-intensity training.     

Block periodization of high‐intensity aerobic intervals provides superior training effects in trained cyclists

The purpose of this study was to compare the effect of two different methods of organizing endurance training in trained cyclists. One group of cyclists performed block periodization, wherein the first week constituted five sessions of high‐intensity aerobic training (HIT), followed by 3 weeks of one weekly HIT session and focus on low‐intensity training (LIT) (BP; n = 10, VO_2max = 62 ± 2 mL/kg/min). Another group of cyclists performed a more traditional organization, with 4 weeks of two weekly HIT sessions interspersed with LIT (TRAD; n = 9, VO_2max = 63 ± 2 mL/kg/min). Similar volumes of both HIT and LIT was performed in the two groups. While BP increased VO_2max, peak power output (W_max) and power output at 2 mmol/L [la^?] by 4.6 ± 3.7%, 2.1 ± 2.8%, and 10 ± 12%, respectively (P < 0.05), no changes occurred in TRAD. BP showed relative improvements in VO_2max compared with TRAD (P < 0.05). Mean effect size (ES) of the relative improvement in VO_2max, W_max, and power output at 2 mmol/L [la^?] revealed large to moderate effects of BP training compared with TRAD training (ES = 1.34, ES = 0.85, and ES = 0.71, respectively). The present study suggests that block periodization of training provides superior adaptations to traditional organization during a 4‐week endurance training period, despite similar training volume and intensity.     

Physiological responses to a 6-d taper in middle-distance runners: influence of training intensity and volume

PURPOSE: This study examined some physiological and performance responses to a 6-d taper, and the influence of training intensity and volume on these responses. METHODS: After 15 wk of training, 8 well-trained male middle-distance runners were randomly assigned to either a moderate volume taper (MVT, N = 4) or a low volume taper (LVT, N = 4), consisting of either a 50% or a 75% progressive reduction in pretaper low intensity continuous training (LICT) and high intensity interval training (HIIT). Blood samples were obtained and 800-m running performance was measured before and after taper. RESULTS: Performance was not significantly enhanced by either taper protocol (post- vs pre-taper times 124.9 +/- 4.5 vs 126.1 +/- 4.2 s with LVT, 126.2 +/- 8.0 vs 125.7 +/- 6.6 s with MVT). For the entire group of 8 subjects, red cell count, hemoglobin (Hb), mean corpuscular volume and mean corpuscular Hb concentration significantly decreased with taper, while reticulocyte count increased. Performance changes for all subjects correlated with changes in postrace peak blood lactate concentration (r = 0.87, P < 0.01). Taper LICT correlated with changes in Hb (r = 0.77), hematocrit (r = 0.81), reticulocyte count (r = 0.73), creatine kinase (r = 0.72), and total testosterone (r = -0.78), and with posttaper red cell distribution width (r = -0.75) and lymphocyte count (r = -0.82). Taper HIIT correlated nonsignificantly with changes in red cell count (r = -0.66) and total testosterone (r = 0.68). CONCLUSION: It is concluded that taper-induced physiological changes in trained middle-distance runners are mainly hematological, and that distinct physiological changes are elicited from LICT and HIIT during taper. Middle-distance runners can progressively reduce their usual training volume by at least 75% during a 6-d taper.     

Training techniques to improve endurance exercise performances

In previously untrained individuals, endurance training improves peak oxygen uptake (VO2peak), increases capillary density of working muscle, raises blood volume and decreases heart rate during exercise at the same absolute intensity. In contrast, sprint training has a greater effect on muscle glyco(geno)lytic capacity than on muscle mitochondrial content. Sprint training invariably raises the activity of one or more of the muscle glyco(geno)lytic or related enzymes and enhances sarcolemmal lactate transport capacity. Some groups have also reported that sprint training transforms muscle fibre types, but these data are conflicting and not supported by any consistent alteration in sarcoplasmic reticulum Ca2+ ATPase activity or muscle physicochemical H+ buffering capacity. While the adaptations to training have been studied extensively in previously sedentary individuals, far less is known about the responses to high-intensity interval training (HIT) in already highly trained athletes. Only one group has systematically studied the reported benefits of HIT before competition. They found that >or=6 HIT sessions, was sufficient to maximally increase peak work rate (W(peak)) values and simulated 40 km time-trial (TT(40)) speeds of competitive cyclists by 4 to 5% and 3.0 to 3.5%, respectively. Maximum 3.0 to 3.5% improvements in TT(40) cycle rides at 75 to 80% of W(peak) after HIT consisting of 4- to 5-minute rides at 80 to 85% of W(peak) supported the idea that athletes should train for competition at exercise intensities specific to their event. The optimum reduction or 'taper' in intense training to recover from exhaustive exercise before a competition is poorly understood. Most studies have shown that 20 to 80% single-step reductions in training volume over 1 to 4 weeks have little effect on exercise performance, and that it is more important to maintain training intensity than training volume. Progressive 30 to 75% reductions in pool training volume over 2 to 4 weeks have been shown to improve swimming performances by 2 to 3%. Equally rapid exponential tapers improved 5 km running times by up to 6%. We found that a 50% single-step reduction in HIT at 70% of W(peak) produced peak approximately 6% improvements in simulated 100 km time-trial performances after 2 weeks. It is possible that the optimum taper depends on the intensity of the athletes' preceding training and their need to recover from exhaustive exercise to compete. How the optimum duration of a taper is influenced by preceding training intensity and percentage reduction in training volume warrants investigation.     

Interval training program optimization in highly trained endurance cyclists

PURPOSE: The purpose of this study was to examine the influence of three different high-intensity interval training (HIT) regimens on endurance performance in highly trained endurance athletes. METHODS: Before, and after 2 and 4 wk of training, 38 cyclists and triathletes (mean +/- SD; age = 25 +/- 6 yr; mass = 75 +/- 7 kg; VO(2peak) = 64.5 +/- 5.2 mL x kg(-1) min(-1)) performed: 1) a progressive cycle test to measure peak oxygen consumption (VO(2peak)) and peak aerobic power output (PPO), 2) a time to exhaustion test (T(max)) at their VO(2peak) power output (P(max)), as well as 3) a 40-km time-trial (TT(40)). Subjects were matched and assigned to one of four training groups (G(2), N = 8, 8 x 60% T(max) at P(max), 1:2 work:recovery ratio; G(2), N = 9, 8 x 60% T(max) at P(max), recovery at 65% HR(max); G(3), N = 10, 12 x 30 s at 175% PPO, 4.5-min recovery; G(CON), N = 11). In addition to G(1), G(2), and G(3) performing HIT twice per week, all athletes maintained their regular low-intensity training throughout the experimental period. RESULTS: All HIT groups improved TT(40) performance (+4.4 to +5.8%) and PPO (+3.0 to +6.2%) significantly more than G(CON) (-0.9 to +1.1%; P < 0.05). Furthermore, G(1) (+5.4%) and G(2) (+8.1%) improved their VO(2peak) significantly more than G(CON) (+1.0%; P < 0.05). CONCLUSION: The present study has shown that when HIT incorporates P(max) as the interval intensity and 60% of T(max) as the interval duration, already highly trained cyclists can significantly improve their 40-km time trial performance. Moreover, the present data confirm prior research, in that repeated supramaximal HIT can significantly improve 40-km time trial performance.     

Nonconsecutive- versus consecutive-day high-intensity interval training in cyclists

PURPOSE: We compared the effects of a high-intensity interval training (HIT) program completed on three consecutive or nonconsecutive days per week for 3 wk on VO2peak, peak aerobic power output (PPOa), and 5-km time trial (TT5k) performance in trained cyclists. METHODS: Fifteen trained cyclists completed a TT5k and an incremental test to exhaustion for VO2peak and PPOa determination before and after training. Pretraining TT5k times were used to form groups, one of which (N=9) performed three HIT sessions per week on consecutive days (CD), while the other (N=6) did so on nonconsecutive days (NCD). Each interval session consisted of up to eight 2.5-min intervals at 100% of PPOa, separated by 4 min of active recovery. Pre- and posttraining TT5k performance, VO2peak, and PPOa were compared using 2x2 (groupxtime) ANOVA with repeated measures on time. RESULTS: HIT significantly improved VO2peak, PPOa, and TT5k performance in both groups across time (P<0.05); there were no differences between groups. In both groups combined, VO2peak and PPOa increased by 0.2+/-0.2 L.min(-1) (5.7%) and 23+/-15 W (7.2%), respectively, and TT5k velocity and power output increased by 0.9+/-0.8 km.h(-1) (2.6%) and 17+/-19 W (6.9%), respectively. Despite comparable group changes, the individual response varied widely. CONCLUSION: CD and NCD similarly improved TT5k performance, VO2peak, and PPOa, but the individual response varied widely in each group. Thus, athletes should experiment with both designs to discern which one optimizes their training.     

Effect of swim taper on whole muscle and single muscle fiber contractile properties

TRAPPE, S., D. COSTILL, and R. THOMAS. Effect of swim taper on whole muscle and single muscle fiber contractile properties. Med. Sci. Sports Exerc., Vol. 32, No. 12, 2000, pp. 48-56. Purpose: To examine the changes in whole muscle function and single cell contractile properties of Type I and II muscle fibers from the deltoid muscle of highly trained swimmers before and after a 21-d reduction in training volume (taper). Methods: Six college male swimmers (age, 20 +/- 1 yr; height, 187 +/- 2 cm, weight, 79 +/- 3 kg, fat, 7 +/- 1%) who had been, on average, swimming 6200 m.d-1 for 5 months before the taper participated in this investigation. Results: Whole muscle power increased (P < 0.05) 17% and 13% on the swim bench and swim power tests, respectively. Swim times improved by 4% (range: 3.0-4.7%; P < 0.05). There was no change in Type I fiber diameter, whereas Type IIa fibers were 11% larger (P < 0.05) after taper. Peak force (Po) of the Type I fibers was unaffected by the taper but increased (P < 0.05) from 0.63 +/- 0.02 to 0.82 +/- 0.05 mN in the IIa fibers. However, the specific force (Po/CSA) of the IIa fibers was unchanged. Shortening velocity (Vo) was 32% and 67% faster (P < 0.05) in the Type I and IIa fibers, respectively. Although Type I fiber power was unaltered, the IIa fibers increased 2.5-fold from 24.6 +/- 2.8 to 56.2 +/- 3.9 μN.FL.s-1. When power was normalized for cell size, the power was still elevated twofold. Conclusions: These data suggest that tapering induces alterations in the contractile properties of single muscle fibers. Further, it appears that the Type IIa fibers are more affected than the Type I fibers by the taper. The increased size, strength, velocity, and power of the IIa fibers may be responsible for the improvements in whole muscle strength and power after the taper.     

The scientific basis for high-intensity interval training: optimising training programmes and maximising performance in highly trained endurance athletes.

While the physiological adaptations that occur following endurance training in previously sedentary and recreationally active individuals are relatively well understood, the adaptations to training in already highly trained endurance athletes remain unclear. While significant improvements in endurance performance and corresponding physiological markers are evident following submaximal endurance training in sedentary and recreationally active groups, an additional increase in submaximal training (i.e. volume) in highly trained individuals does not appear to further enhance either endurance performance or associated physiological variables [e.g. peak oxygen uptake (VO2peak), oxidative enzyme activity]. It seems that, for athletes who are already trained, improvements in endurance performance can be achieved only through high-intensity interval training (HIT). The limited research which has examined changes in muscle enzyme activity in highly trained athletes, following HIT, has revealed no change in oxidative or glycolytic enzyme activity, despite significant improvements in endurance performance (p < 0.05). Instead, an increase in skeletal muscle buffering capacity may be one mechanism responsible for an improvement in endurance performance. Changes in plasma volume, stroke volume, as well as muscle cation pumps, myoglobin, capillary density and fibre type characteristics have yet to be investigated in response to HIT with the highly trained athlete. Information relating to HIT programme optimisation in endurance athletes is also very sparse. Preliminary work using the velocity at which VO2max is achieved (V(max)) as the interval intensity, and fractions (50 to 75%) of the time to exhaustion at V(max) (T(max)) as the interval duration has been successful in eliciting improvements in performance in long-distance runners. However, V(max) and T(max) have not been used with cyclists. Instead, HIT programme optimisation research in cyclists has revealed that repeated supramaximal sprinting may be equally effective as more traditional HIT programmes for eliciting improvements in endurance performance. Further examination of the biochemical and physiological adaptations which accompany different HIT programmes, as well as investigation into the optimal HIT programme for eliciting performance enhancements in highly trained athletes is required.     

Physiological and performance responses to a 6-day taper in middle-distance runners: influence of training frequency

The purpose of this investigation was to examine the influence of training frequency on performance and some physiological responses during a 6-day taper. After 18 weeks of training, 9 male middle-distance runners were assigned to a high frequency taper (HFT, n = 5) or a moderate frequency taper (MFT, n = 4), consisting of training daily or resting every third day of the taper. Taper consisted of an 80% nonlinear progressive reduction in high intensity interval training. Blood samples were obtained, and 800 m performance and peak blood lactate ([La] peak ) measured before and after taper. Performance improved significantly after HFT (121.8 +/- 4.7 vs 124.2 +/- 4.9 s, p < 0.05), but not after MFT (126.6 +/- 2.8 vs 127.1 +/- 2.1 s). Neutrophils (2.89 +/- 0.68 vs 2.56 +/- 0.61 10 (3) x mm(-3)), granulocytes (3.08 +/- 0.70 vs 2.77 +/- 0.66 10 (3) x mm(-3)), haptoglobin (79.7 +/- 47.9 vs 60.7 +/- 33.6 mg x dl(-1)), total testosterone (7.39 +/- 1.67 vs 5.52 +/- 0.88 microg x l(-1)) and [La] peak (15.5 +/- 1.5 vs 14.4 +/- 2.0 mmol x l(-1)) significantly increased with taper. [La] peak correlated with performance time before taper (r = -0.76, p < 0.05), and change in [La] peak with change in serum cortisol (r = -0.75, p < 0.05) and total testosterone:cortisol ratio (r = 0.82, p < 0.01). In conclusion, training daily during a 6-day taper brought about significant performance gains, whereas resting every third day did not. High [La] peak and a hormonal milieu propitious to anabolic processes seemed to be necessary for optimum performance.     

Effect of swim taper on whole muscle and single muscle fiber contractile properties

PURPOSE: To examine the changes in whole muscle function and single cell contractile properties of Type I and II muscle fibers from the deltoid muscle of highly trained swimmers before and after a 21-d reduction in training volume (taper). METHODS: Six college male swimmers (age, 20+/-1 yr; height, 187+/-2 cm, weight, 79+/-3 kg, fat, 7+/-1%) who had been, on average, swimming 6200 m x d(-1) for 5 months before the taper participated in this investigation. RESULTS: Whole muscle power increased (P < 0.05) 17% and 13% on the swim bench and swim power tests, respectively. Swim times improved by 4% (range: 3.0-4.7%; P < 0.05). There was no change in Type I fiber diameter, whereas Type IIa fibers were 11% larger (P < 0.05) after taper. Peak force (Po) of the Type I fibers was unaffected by the taper but increased (P < 0.05) from 0.63+/-0.02 to 0.82+/-0.05 mN in the IIa fibers. However, the specific force (Po/CSA) of the IIa fibers was unchanged. Shortening velocity (Vo) was 32% and 67% faster (P < 0.05) in the Type I and IIa fibers, respectively. Although Type I fiber power was unaltered, the IIa fibers increased 2.5-fold from 24.6+/-2.8 to 56.2+/-3.9 microN x FL x s(-1). When power was normalized for cell size, the power was still elevated twofold. CONCLUSIONS: These data suggest that tapering induces alterations in the contractile properties of single muscle fibers. Further, it appears that the Type IIa fibers are more affected than the Type I fibers by the taper. The increased size, strength, velocity, and power of the IIa fibers may be responsible for the improvements in whole muscle strength and power after the taper.     

Effects of high- and moderate-intensity training on metabolism and repeated sprints

PURPOSE: We compared the effects of high-intensity interval (HIT) and moderate-intensity continuous (MIT) training (matched for total work) on changes in repeated-sprint ability (RSA) and muscle metabolism. METHODS: Pre- and posttraining, VO(2peak), lactate threshold (LT), and RSA (5 x 6-s sprints, every 30 s) were assessed in 20 females. Before and immediately after the RSA test, muscle biopsies were taken from the vastus lateralis. Subjects were matched on RSA, randomly placed into the HIT (N = 10) or MIT (N = 10) group and performed 5 wk (3 d.wk(-1)) of cycle training; performing either HIT (6-10, 2-min intervals at 120-140% LT) or MIT (continuous, 20-30 min at 80-95% LT). RESULTS: Both groups had significant improvements in VO(2peak) (10-12%; P < 0.05) and LT (8-10%; P < 0.05), with no significant differences between them. Both groups also had significant increases in RSA total work (kJ) (P < 0.05), with a significantly greater increase following HIT than MIT (13 vs 8.5%, respectively; P < 0.05). There was a significant decrease in resting [ATP] and an increase in postexercise [La(-)](b) for both groups, but no significant differences between them. There were no significant changes in resting or postexercise [PCr], [Cr], muscle [La(-)], or [H(+)] after the training period. CONCLUSIONS: When total work is matched, HIT results in greater improvements in RSA than MIT. This results from an improved ability to maintain performance during consecutive sprints, which is not explained by differences in work done during the first sprint, aerobic fitness or metabolite accumulation at the end of the sprints.     

Challenges in understanding the influence of maximal power training on improving athletic performance

The ability to optimise muscular power output is considered fundamental to successful performance of many athletic and sporting activities. Consequently, a great deal of research has investigated methods to improve power output and its transference to athletic performance. One issue that makes comparisons between studies difficult is the different modes of dynamometry (isometric, isokinetic and isoinertial) used to measure strength and power. However, it is recognised that isokinetic and isometric assessment bear little resemblance to the accelerative/decelerative motion implicit in limb movement during resistance training and sporting performance. Furthermore, most people who train to increase power would have limited or no access to isometric and/or isokinetic dynamometry. It is for these reasons and for the sake of brevity that the findings of isoinertial (constant gravitational load) research will provide the focus of much of the discussion in this review. One variable that is considered important in increasing power and performance in explosive tasks such as running and jumping is the training load that maximises the mechanical power output (Pmax) of muscle. However, there are discrepancies in the research as to which load maximises power output during various resistance exercises and whether training at Pmax improves functional performance is debatable. There is also some evidence suggesting that Pmax is affected by the training status of the individuals; however, other strength variables could quite possibly be of greater importance for improving functional performance. If Pmax is found to be important in improving athletic performance, then each individual's Pmax needs to be determined and they then train at this load. The predilection of research to train all subjects at one load (e.g. 30% one repetition maximum [1RM]) is fundamentally flawed due to inter-individual Pmax differences, which may be ascribed to factors such as training status (strength level) and the exercise (muscle groups) used. Pmax needs to be constantly monitored and adjusted as research suggests that it is transient. In terms of training studies, experienced subjects should be used, volume equated and the outcome measures clearly defined and measured (i.e. mean power and/or peak power). Sport scientists are urged to formulate research designs that result in meaningful and practical information that assists coaches and strength and conditioning practitioners in the development of their athletes.     

Relationship between upper body anaerobic power and freestyle swimming performance

The purpose of this study was to examine the role of upper body anaerobic power, as measured by the Wingate Anaerobic Arm Test (WAAT), in 50-m sprint swim performance. Thirty competitive age-group swimmers (14 males and 16 females) participated in this investigation. Subjects had been training daily for 5 months prior to the study, swimming an average of 6,000 m.d-1, 6 d.wk-1. Swimmers performed a WAAT and a 50-m time-trial. Peak power (PP), mean power (MP) and fatigue index (FI) were determined for the WAAT. Subjects also reported their current competition performances for all distances up to 400 m. Significant relationships were obtained between swim speed over 50 m (S50) and PP (r = 0.82, p less than 0.001), S50 and MP (r = 0.83, p less than 0.001), and S50 and FI (r = 0.41, p less than 0.05). PP and MP showed significant but generally decreasing correlations with swim speed as distance increased. Substantial relationships (r = 0.74-0.96, p less than 0.001) were found between S50 and swim speeds over distances up to and including 400 m. This study shows a strong relationship exists between upper body anaerobic power, as measured by the WAAT, and performance in both sprint and longer distance (400 m) swim events. The WAAT may serve as a useful tool for coaches to objectively evaluate and monitor the upper body anaerobic power of competitive swimmers.     

Supramaximal training and postexercise parasympathetic reactivation in adolescents.

Repeated supramaximal exercise training is an efficient means of improving both aerobic and anaerobic energy system capacities. However, the influence of different levels of supramaximal training on parasympathetic function is unknown. PURPOSE: To compare the effects of repeated-sprint (RS) versus high-intensity intermittent training (HIT) on performance and postexercise parasympathetic reactivation in trained adolescents. METHODS: Fifteen male adolescents (15.6 +/- 0.8 yr) were divided into two groups that performed 9 wk of either RS (repeated all-out 6-s shuttle sprints; 14-20 s of recovery; N = 8) or HIT (15- to 20-s runs at 95% of the speed reached at the end of the 30-15 intermittent fitness test (V(IFT)); 15-20 s of recovery; N = 7). Groups performed intervals twice per week and maintained similar external training programs. Before and after training, performance was assessed by the V(IFT), countermovement jump (CMJ), 10-m sprint time (10 m), mean RS ability time (RSAmean), and heart rate (HRsub) level during a 6-min submaximal (60% V(IFT)) exercise test, where parasympathetic reactivation was assessed during the recovery phase (i.e., HR recovery time constant (HRRtau) and HR variability (HRV)). RESULTS: Parasympathetic function, V(IFT), and RSAmean were improved with HIT but not RS training. In contrast, changes in CMJ and HRsub were similar in both groups. A significant relationship was shown between the decrease in HRRtau and RSAmean (r = 0.62, P < 0.05; N = 15). CONCLUSION: HIT was more effective than RS training at improving postexercise parasympathetic function and physical performance. In addition, HRRtau, which was more sensitive to training than HRV indices, seems to be a useful performance-related measurement.     

Effect of hyperoxic-supplemented interval training on endurance performance in trained cyclists

The aim of this study was to determine the effect of hyperoxic-supplemented interval training on endurance performance. Using a single-blind, randomised control-trial design, 16 well-trained cyclists were randomly assigned to either hyperoxic or normoxic training. Participants visited the laboratory twice per week, for 4 weeks, to perform high-intensity interval training sessions. A 20 km TT, incremental exercise test and 60s all-out test were conducted pre- and post-intervention. Smaller effects for most physiological measures, including VO 2peak (1.9 ± 4.3%) and lactate threshold (0.3 ± 8.3%), were observed after training in hyperoxia compared to normoxia. There was a small increase in mean power during the 20 km TT after hyperoxia [2.1 ± 3.7%; effect size (ES): - 0.30 ± 0.39] but this was less than that observed after normoxia (4.9 ± 3.9%; ES: - 0.44 ± 0.60). During the 60 s all-out test, the peak relative power was relatively unchanged, whereas mean relative power was increased in normoxia (2.3 ± 3.4%) but not hyperoxia (0.3 ± 1.2%; ES: - 0.34 ± 0.49). Hyperoxic-supplemented interval training in the competitive season had less effect on endurance and high-intensity performance and physiology in trained endurance cyclists compared to interval training in normoxia. Therefore hyperoxic-supplemented training at sea level appears to be not worthwhile for maximising performance in competitive endurance athletes.