Bent R. Rønnestad

Short-term effects of strength and plyometric training on sprint and jump performance in Professional Soccer Players

The purpose of this study was to compare the effects of combined strength and plyometric training with strength training alone on power-related measurements in professional soccer players. Subjects in the intervention team were randomly divided into 2 groups. Group ST (n = 6) performed heavy strength training twice a week for 7 weeks in addition to 6 to 8 soccer sessions a week. Group ST+P (n = 8) performed a plyometric training program in addition to the same training as the ST group. The control group (n = 7) performed 6 to 8 soccer sessions a week. Pretests and posttests were 1 repetition maximum (1RM) half squat, countermovement jump (CMJ), squat jump (SJ), 4-bounce test (4BT), peak power in half squat with 20 kg, 35 kg, and 50 kg (PP20, PP35, and PP50, respectively), sprint acceleration, peak sprint velocity, and total time on 40-m sprint. There were no significant differences between the ST+P group and ST group. Thus, the groups were pooled into 1 intervention group. The intervention group significantly improved in all measurements except CMJ, while the control group showed significant improvements only in PP20. There was a significant difference in relative improvement between the intervention group and control group in 1RM half squat, 4BT, and SJ. However, a significant difference between groups was not observed in PP20, PP35, sprint acceleration, peak sprinting velocity, and total time on 40-m sprint. The results suggest that there are no significant performance-enhancing effects of combining strength and plyometric training in professional soccer players concurrently performing 6 to 8 soccer sessions a week compared to strength training alone. However, heavy strength training leads to significant gains in strength and power-related measurements in professional soccer players.

Vitamin C and E supplementation hampers cellular adaptation to endurance training in humans: a double-blind, randomised, controlled trial

Recent studies have indicated that antioxidant supplementation may blunt adaptations to exercise, such as mitochondrial biogenesis induced by endurance training. However, studies in humans are sparse and results are conflicting. Isolated vitamin C and E supplements are widely used, and unravelling the interference of these vitamins in cellular and physiological adaptations to exercise is of interest to those who exercise for health purposes and to athletes. Our results show that vitamin C and E supplements blunted the endurance training‐induced increase of mitochondrial proteins (COX4), which is important for improving muscular endurance. Training‐induced increases in V̇O2 max and running performance were not detectably affected by the supplementation. The present study contributes to understanding of how antioxidants may interfere with adaptations to exercise in humans, and the results indicate that high dosages of vitamins C and E should be used with caution.

Dissimilar Effects of One- and Three-Set Strength Training on Strength and Muscle Mass Gains in Upper and Lower Body in Untrained Subjects

The purpose of this study was to compare the effects of single- and multiple-set strength training on hypertrophy and strength gains in untrained men. Twenty-one young men were randomly assigned to either the 3L-1UB group (trained 3 sets in leg exercises and 1 set in upper-body exercises; n = 11), or the 1L-3UB (trained 1 set in leg exercises and 3 sets in upper-body exercises; n = 10). Subjects trained 3 days per week for 11 weeks and each workout consisted of 3 leg exercises and 5 upper-body exercises. Training intensity varied between 10 repetition maximum (RM) and 7RM. Strength (1RM) was tested in all leg and upper-body exercises and in 2 isokinetic tests before training, and after 3, 6, 9, and 11 weeks of training. Cross sectional area (CSA) of thigh muscles and the trapezius muscle and body composition measures were performed before training, and after 5 and 11 weeks of training. The increase in 1RM from week 0 to 11 in the lower-body exercises was significantly higher in the 3L-1UB group than in the 1L-3UB group (41 vs. 21%; p < 0.001), while no difference existed between groups in upper-body exercises. Peak torque in maximal isokinetic knee-extension and thigh CSA increased more in the 3L- 1UB group than in the 1L-3UB group (16 vs. 8%; p = 0.03 and 11 vs. 7%; p = 0.01, respectively), while there was no significant difference between groups in upper trapezius muscle CSA. The results demonstrate that 3-set strength training is superior to 1-set strength training with regard to strength and muscle mass gains in the leg muscles, while no difference exists between 1- and 3-set training in upper-body muscles in untrained men.

Acute Effects of Various Whole-Body Vibration Frequencies on Lower-Body Power in Trained and Untrained Subjects

Rønnestad, BR. Acute effects of various whole-body vibration frequencies on lower-body power in trained and untrained subjects. J Strength Cond Res 23(4): 1309-1315, 2009-The purpose of this study was to investigate the acute effects of whole-body vibration (WBV) with different vibration frequencies on power production during squat jump (SJ) and countermovement jump (CMJ) with submaximal external loads in strength trained and untrained subjects. Subjects were randomly exposed to WBV with frequencies of 20, 35, or 50 Hz (amplitude: 3 mm), or no vibration. Peak average power during SJ and CMJ was assessed on a Smith machine while standing on a vibration platform. Both the trained and untrained group increased peak average power during SJ at an WBV frequency of 50 Hz (6.8 ± 1.9 and 7.3 ± 1.7%, respectively; p < 0.05). This increase was larger than in the other test conditions, in which no changes occurred (p < 0.05). Untrained subjects increased peak average power during CMJ with 4.4 ± 1.3% (p < 0.05) while vibrating at a frequency of 50 Hz, but there was no difference for the strength trained subjects. Furthermore, there was no difference in peak average power in CMJ and SJ while vibrating at frequencies of 20 and 35 Hz compared with no vibration in either of the groups. In conclusion, WBV with a frequency of 50 Hz increases peak average power in both trained and untrained subjects, whereas vibration frequencies of 20 and 35 Hz do not have this effect. Thus, if the purpose of using WBV is to increase the stimulus to the neuromuscular system to a greater extent than traditional explosive strength/power training, the WBV frequency should be 50 Hz and the exercises should be explosive and submaximally loaded (like traditional explosive strength/power training).

The effect of heavy strength training on muscle mass and physical performance in elite cross country skiers

Aim: To investigate the effect of supplementing high‐volume endurance training with heavy strength training on muscle adaptations and physical performance in elite cross country skiers. Eleven male (18–26 years) and eight female (18–27 years) were assigned to either a strength group (STR) (n=9) or a control group (CON) (n=10). STR performed strength training twice a week for 12 weeks in addition to their normal endurance training. STR improved 1 repetition maximum (RM) for seated pull‐down and half squat (19±2% and 12±2%, respectively), while no change was observed in CON. Cross‐sectional area (CSA) increased in m. triceps brachii for both STR and CON, while there was no change in the m. quadriceps CSA. VO2max during skate‐rollerskiing increased in STR (7±1%), while VO2max during running was unchanged. No change was observed in energy consumption during rollerskiing at submaximal intensities. Double‐poling performance improved more for STR than for CON. Both groups showed a similar improvement in rollerski time‐trial performance. In conclusion, 12 weeks of supplemental heavy strength training improved the strength in leg and upper body muscles, but had little effect on the muscle CSA in thigh muscles. The supplemental strength training improved both VO2max during skate‐rollerskiing and double‐poling performance.

Optimizing strength training for running and cycling endurance performance: A review

Here we report on the effect of combining endurance training with heavy or explosive strength training on endurance performance in endurance‐trained runners and cyclists. Running economy is improved by performing combined endurance training with either heavy or explosive strength training. However, heavy strength training is recommended for improving cycling economy. Equivocal findings exist regarding the effects on power output or velocity at the lactate threshold. Concurrent endurance and heavy strength training can increase running speed and power output at VO2max (Vmax and Wmax, respectively) or time to exhaustion at Vmax and Wmax. Combining endurance training with either explosive or heavy strength training can improve running performance, while there is most compelling evidence of an additive effect on cycling performance when heavy strength training is used. It is suggested that the improved endurance performance may relate to delayed activation of less efficient type II fibers, improved neuromuscular efficiency, conversion of fast‐twitch type IIX fibers into more fatigue‐resistant type IIA fibers, or improved musculo‐tendinous stiffness.

Strength training improves 5-min all-out performance following 185 min of cycling

To investigate the effects of heavy strength training on the mean power output in a 5‐min all‐out trial following 185 min of submaximal cycling at 44% of maximal aerobic power output in well‐trained cyclists. Twenty well‐trained cyclists were assigned to either usual endurance training combined with heavy strength training [E+S; n=11 (♂=11)] or to usual endurance training only [E; n=9 (♂=7, ♀=2)]. The strength training performed by E+S consisted of four lower body exercises [3 × 4–10 repetition maximum (RM)], which were performed twice a week for 12 weeks. E+S increased 1 RM in half‐squat (P≤0.001), while no change occurred in E. E+S led to greater reductions than E in oxygen consumption, heart rate, blood lactate concentration, and rate of perceived exertion (P<0.05) during the last hour of the prolonged cycling. Further, E+S increased the mean power output during the 5‐min all‐out trial (from 371 ± 9 to 400 ± 13 W, P<0.05), while no change occurred in E. In conclusion, adding strength training to usual endurance training improves leg strength and 5‐min all‐out performance following 185 min of cycling in well‐trained cyclists.

Effects of in-season strength maintenance training frequency in professional soccer players

Rønnestad, BR, Nymark, BS, and Raastad, T. Effects of in-season strength maintenance training frequency in professional soccer players. J Strength Cond Res 25(10): 2653–2660, 2011–The aim of the present study was to examine the effect of in-season strength maintenance training frequency on strength, jump height, and 40-m sprint performance in professional soccer players. The players performed the same strength training program twice a week during a 10-week preparatory period. In-season, one group of players performed 1 strength maintenance training session per week (group 2 + 1; n = 7), whereas the other group performed 1 session every second week (group 2 + 0.5; n = 7). Only the strength training frequency during the in-season differed between the groups, whereas the exercise, sets and number of repetition maximum as well as soccer sessions were similar in the 2 groups. The preseason strength training resulted in an increased strength, sprint, and jump height (p < 0.05). During the first 12 weeks of the in-season, the initial gain in strength and 40-m sprint performance was maintained in group 2 + 1, whereas both strength and sprint performance were reduced in group 2 + 0.5 (p < 0.05). There was no statistical significant change in jump height in any of the 2 groups during the first 12 weeks of the in-season. In conclusion, performing 1 weekly strength maintenance session during the first 12 weeks of the in-season allowed professional soccer players to maintain the improved strength, sprint, and jump performance achieved during a preceding 10-week preparatory period. On the other hand, performing only 1 strength maintenance session every second week during the in-season resulted in reduced leg strength and 40-m sprint performance. The practical recommendation from the present study is that during a 12-week period, 1 strength maintenance session per week may be sufficient to maintain initial gain in strength and sprint performance achieved during a preceding preparatory period.

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, VO2max = 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, VO2max = 63 ± 2 mL/kg/min). Similar volumes of both HIT and LIT was performed in the two groups. While BP increased VO2max, peak power output (Wmax) 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 VO2max compared with TRAD (P < 0.05). Mean effect size (ES) of the relative improvement in VO2max, Wmax, 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.

Acute Effects of Various Whole Body Vibration Frequencies on 1RM in Trained and Untrained Subjects

Rønnestad, BR. Acute effects of various whole body vibration frequencies on 1RM in trained and untrained subjects. J Strength Cond Res 23(7): 2068-2072, 2009-The purpose of this study was to compare the acute effects of whole body vibration (WBV) at different vibration frequencies on 1 repetition maximum (1RM) in recreationally strength trained subjects and untrained subjects. While performing a 1RM test in half squat, trained (8 men) and untrained (5 men and 3 women) subjects were randomly exposed to WBV with a frequency of 20 Hz, 35 Hz, 50 Hz (amplitude, 3 mm), or control conditions with no vibration. 1RM in half squat was assessed in a Smith Machine while subjects were standing on a vibration platform. Both untrained and recreationally strength trained subjects increased their 1RM at a vibration frequency of 50 Hz compared with no vibration (p < 0.05), and untrained subjects increased their 1RM to a larger extent than recreationally trained subjects (8.7% vs. 4.9%; p < 0.05). However, there was no difference in 1RM while vibrating at a frequency of 20 Hz and 35 Hz compared with no vibrations in either of the groups. In conclusion, WBV with a frequency of 50 Hz increases 1RM in both recreationally strength trained and untrained subjects, whereas vibration frequencies of 20 Hz and 35 Hz do not have this effect. Untrained subjects increased their 1RM at WBV at 50 Hz to a larger extent than recreationally strength trained subjects. Therefore, if the purpose is to increase the stimulus to the neuromuscular system to a greater extent than traditional strength training, the WBV frequency should be 50 Hz and the exercises should be heavily loaded (as in traditional strength training).