Strength Training for Endurance Athletes: Theory to Practice Caleb D

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Strength Training for Endurance Athletes: Theory to Practice Caleb D. Bazyler, MA, Heather A. Abbott, M.Ed, Christopher R. Bellon, MA, Christopher B. Taber, MS, and Michael H. Stone, PhD Department of Exercise and Sport Science, East Tennessee State University, Johnson City, Tennessee

ABSTRACT supporting its efficacy and applica- aerobic power (V̇O2max) and LIEE tion (34-36,46,47,58,64,65,67,71,82). (34). Requirements for endurance ath- THE PURPOSE OF THIS REVIEW IS Historically, resistance and endurance letes should also include muscular TWOFOLD: TO ELUCIDATE THE training have been viewed as training strength, anaerobic power, and HIEE UTILITY OF RESISTANCE TRAINING modalities at opposite ends of a contin- (34-36,46,58,68,82). Furthermore, FOR ENDURANCE ATHLETES, AND uum with divergent adaptations (17,41). strength training has been shown to PROVIDE THE PRACTITIONER WITH In a recent meta-analysis, Wilson et al. positively influence both LIEE and EVIDENCED-BASED PERIODIZATION (92) reported an inverse relationship HIEE across a spectrum of endurance STRATEGIES FOR CONCURRENT between frequency and duration of events with greater effects observed in STRENGTH AND ENDURANCE endurance training and subsequent HIEE (34,46,50,58,82,83). TRAINING IN ATHLETIC POPULA- changes in hypertrophy, strength, Strength can be defined as the ability to TIONS. BOTH LOW-INTENSITY and power. Alternatively, strength produce force (76). Strength is a skill, EXERCISE ENDURANCE (LIEE) AND training has been shown to have which can be expressed in a magnitude HIGH-INTENSITY EXERCISE ENDUR- apositiveeffectonenduranceperfor- of 0–100% (80). In the current endur- ANCE (HIEE) HAVE BEEN SHOWN mance (46,49,51,65,73). Previous research ance literature, 2 primary forms of TO IMPROVE AS A RESULT OF reports that concurrent strength and strength training have been investigated: MAXIMAL, HIGH FORCE, LOW endurance training can increase endur- maximal, high-force, low-velocity, VELOCITY (HFLV) AND EXPLOSIVE, ance performance in high-level athletes strength training (HFLV) and explosive, LOW-FORCE, HIGH-VELOCITY to a greater extent than endurance train- low-force, high-velocity strength train- STRENGTH TRAINING. HFLV ing alone (46,47,58,64,65,82). The inter- ing (LFHV). Previous studies have STRENGTH TRAINING IS RECOM- ference effects between strength and examined the effectiveness of concurrent MENDED INITIALLY TO DEVELOP A endurance training are outside the endurance and circuit resistance train- NEUROMUSCULAR BASE FOR scope of this review and have been ing, but have demonstrated inferior re- ENDURANCE ATHLETES WITH LIM- discussed extensively in previous stud- sults (49,73,84). Maximum strength can ITED STRENGTH TRAINING EXPERI- ies (23,24,44,54,92). Endurance in be defined as the maximal amount of ENCE. A SEQUENCED APPROACH sport has been defined as the ability force a muscle or group of muscles TO STRENGTH TRAINING INVOLVING to maintain or repeat a given force or can exert against an external resistance PHASES OF STRENGTH- power output (80). Endurance training and corresponds with the high-force, ENDURANCE, BASIC STRENGTH, can be further subdivided into low- low-velocity portion of the concentric STRENGTH, AND POWER WILL intensity exercise endurance (LIEE) force-velocity relationship (15,81). The PROVIDE FURTHER ENHANCE- and high-intensity exercise endurance term “explosive strength training” has MENTS IN LIEE AND HIEE FOR HIGH- (HIEE). LIEE can be defined as long- been used in previous studies in refer- ence to low-force, high-velocity training LEVEL ENDURANCE ATHLETES. duration endurance activities or the ability to sustain or to repeat low- (0–60% 1 repetition maximum [RM] intensity exercise. HIEE can be defined loads) with maximal movement intent INTRODUCTION as the ability to sustain or to repeat high-intensity exercise and has been onflicts among coaches exist KEY WORDS: associated with sustained activities of regarding the role of strength periodization; endurance performance; #2 minutes (80). Competitive endur- Ctraining for endurance athletes concurrent training despite over 25 years of research ance athletes need more than enhanced

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(59,69). The use of this terminology is endurance athletes, and provide the prac- Increased MVIC as a result of strength misleading, as explosive strength (alter- titioner with evidenced-based periodiza- training may enhance HIEE and LIEE natively defined as rate of force develop- tion strategies for concurrent strength by decreasing the relative external ment [RFD] or power output) (15,81), and endurance training for competitive resistance, which reduces the number can be developed across a continuum of endurance athletes. of motor units required to produce loads (0–100% 1RM) (19). agivenamountofforce(13).Inaddition, improvements in RFD contributed to the In fact, HFLV training has been shown EFFECTS OF STRENGTH TRAINING to elicit improvements in explosive abil- ON ENDURANCE PERFORMANCE improved LIEE performance by reduc- ity (measured as power output) across AND UNDERLYING MECHANISMS ing time to reach peak concentric forces necessary to produce the desired move- alargerspectrumofloadscompared CONCURRENT HFLV STRENGTH with LFHV training in weak subjects AND ENDURANCE TRAINING ment and increasing the length of the (20). The ability to improve power out- In one of the earliest studies examining eccentric phase lending to greater muscle put across a larger spectrum of loads, the effects of concurrent strength and perfusion and longer capillary mean tran- among other reasons, likely explains endurance training on HIEE, Hickson sit times (1,86). why HFLVand endurance training may et al. (34) had moderately trained Strength training has been reported to provide superior alterations in endurance 21 21 21 (V̇ O2max: 60 mL $kg $min )run- increase musculotendinous unit stiffness performance compared with concurrent ners and cyclists perform 10 weeks of (21,43,51,87). This results in an enhanced LFHV and endurance training for weak endurance and HFLV strength training ability to store elastic energy in the series endurance athletes (9,60,73). Thus, (.80% 1RM). They reported improve- and parallel elastic component during explosive strength training performed ments in treadmill running (13%) and eccentric muscle actions, which in turn in previous research on endurance per- ergometer biking (11%) to exhaustion increases concentric muscle force. This formance is alternatively defined here at maximal work rates (4–8 minutes) is thought to be one of the reasons as LFHV training. and cycling to exhaustion (20%) at 80% why improvements in running economy ̇ Previous research on untrained and rec- VO2max (33). In addition, there were no (35,51,81), cycling economy (8,12,66,83), reationally trained individuals has dem- statistical changes in muscle fiber cross- and cross-country skiing economy onstrated that concurrent strength and sectional area or thigh girth, although (35,36,58) have been observed after endurance training can augment LIEE 1RM leg strength increased on average aperiodofHFLVstrengthandendur- and HIEE, aerobic power, maximal by 30%, which suggests primarily neural ance training. However, not all studies strength, muscle morphology, and body contributions. show improvements in movement econ- composition (27,28,32,34,42,47,49,71,85). In a more recent investigation by omy as a result of strength training There is also research demonstrating Aagaard et al. (2), highly trained (2,9,14,45,46,64) possibly due to differ- HFLV and LFHV strength training en- national team cyclists (V̇O2max: 71–75 ences in training variables (e.g., mode, 2 2 2 hance performance in high-level endur- mL 1$kg 1$min 1) performed HFLV volume-load, frequency, duration) and ance athletes (58,59,61,64,66,72,73). In strength training (mostly 5–6RM loads) subjects’ training status. For example, arecentreviewoftheliterature,Beattie for 16 weeks concurrently with regular elite athletes who already possess a high et al. (10) reviewed results from 26 studies endurance training. The strength and level of efficiency may not further examining the effects of strength training endurance training group improved improve movement economy with on endurance performance of well- average power output and total distance strength training (64). trained athletes (10). Their findings covered in a 45-minute cycling test showed that strength training is effective (8%), whereas the endurance only The superior performance changes with for improving movement economy, group did not. Concomitant increases heavier strength training may be attrib- uted to greater increases in musculoten- velocity at V̇O2max (vV̇O2max), power were found for maximal voluntary iso- dinous unit stiffness, greater recruitment output at V̇O2max (wV̇O2max), maximal metric contraction (MVIC) of the knee of high-threshold motor units, and anaerobic running test velocity (VMART), extensors (12%), peak RFD (20%), and time trial performance, and suggested mean power output in 5 minutes of greater capacity to store and release elas- that HFLVstrength be developed before all-out cycling (3–4%), and mean power tic energy, which lead to a right and LFHV strength in endurance athletes output during a 45-minute time trial upward shift in the force-velocity and with limited strength training experience. (8%) with no changes in muscle fiber force-power relationships (58). This does Considering these findings, this article area, capillarization, and V̇O2max in not preclude LFHV strength training for focuses primarily on studies examining the strength and endurance training endurance athletes because, although the the effects of HFLVand LFHV strength group (2). The superior LIEE perfor- loads used are typically lighter, there are training on HIEE and LIEE of moderate mance in the strength and endurance notable improvements in RFD, which to high-level endurance athletes. The training group may have been due to has been linked to greater movement purpose of this review is twofold: to elu- a shift in vastus lateralis muscle fiber economy and enhanced LIEE and HIEE cidate the utility of resistance training for type from type IIx to type IIa. performance (59,72,85,88).

2 VOLUME 37 | NUMBER 2 | APRIL 2015 Furthermore, an increase in musculo- national level runners (V̇O2max .65 being able to achieve increases in tendinous stiffness has a greater applica- mL21$kg21$min21)(73).Similarly, strength. In addition, increased muscle tion to running than cycling because of Guglielmo et al. (26) found that after fiber cross-sectional area (CSA), maxi- the greater contribution of the stretch- only 4 weeks of concurrent running mal strength, and power output can be shortening cycle (69). In contrast, and heavy strength training (3–5 sets diminished or fully blunted by concur- strength training induced improve- at 6RM loads), there were larger mag- rent strength and endurance training ments on cycling economy and perfor- nitudes of change in running econ- with the degree of decrement depend- mance are more evident at the end of omy, 1RM strength, and CMJ height ing on the mode, frequency, and dura- long cycling tests. Rønnestad et al. (66) compared with concurrent running tion of endurance training (2,14,34,42). found that cycling economy improved and lighter strength training (3–5 sets Rønnestad et al. (64) found that increased more during the final hour of a 185- at 12RM loads) in middle- and long- CSA of the quadriceps muscle was asso- minute cycling test as a result of HFLV distance runners (V̇O2max ;61.9 ciated with increased peak power output 2 2 2 strength with endurance training (3 3 mL 1$kg 1$min 1)whocompetedat and cycling time trial performance after 4–10RM, 2 d/wk for 12 weeks) com- the regional and national level (26). combined heavy strength training pared with endurance training alone Mixed results have been reported for (twice/week, 3 3 4–10RM) and endur- (66). They also reported reduced HR effects of HFLV strength training on ance training in well-trained cyclists with- and blood lactate concentrations dur- cycling economy; however, there are out a noticeable change in body mass ing the final hour in the strength- still improvements in LIEE and HIEE (64). Therefore, altering the strength to trained group. In addition, the subjects performance (2,64,65,83). Furthermore, body mass ratio should be more of a con- completed a 5-minute sprint at the end previous findings suggest that HFLV cern for endurance athletes than body of the 180 minutes during which the strength training may exhibit its effects mass alone. Furthermore, although in- strength-trained group improved average most prominently during high-intensity creases in “nonfunctional” hypertrophy power production, but the endurance on- bouts of endurance events (9,49,66), may be detrimental to performance ly group did not. This “anaerobic reserve” although there is evidence to the con- (3,86,91), increases in task specific may have been due to increased contrac- trary (23,45) (Table 1). hypertrophy may be an important factor tile strength of type I fibers delaying the in enhancing endurance performance, CONCURRENT LFHV STRENGTH as the typical ectomorphic endurance contribution of the less economical type AND ENDURANCE TRAINING athlete is unlikely to gain significant II fibers, sparing them for the sprint finish LFHV strength training has been re- (69). The “anaerobic reserve” for late race amounts of hypertrophy through ported to elicit improvements in HIEE strength training (89). sprint performance may also be ex- and LIEE performance (59,74,85); plained by the sparing of substrate stores however, research conclusions are It has been suggested that LFHV within a muscle. Goreham et al. (25) re- mixed (7,45,60) (Table 2). Paavolainen strength training may provide an addi- ported that 12 weeks of HFLV strength et al. (59) found that LFHV strength tive effect to those elicited by HFLV with endurance training (3 3 6–8RM, training (,40% 1RM) improved 5k run strength training on HIEE and LIEE 3d/wkfor12weeks)resultedingreater performance (85). Taipale et al. (85) time, running economy, VMART,20-m muscle phosphocreatine and glycogen sprint speed, and distance covered on tested this hypothesis by dividing endur- content, and lower lactate concentrations a5-jumptestinmalecross-countryrun- ance runners into 3 groups (LFHV, 21 21 21 HFLV, combination) and found no dif- at the end of a 30-minute cycle at 72% ners (V̇O2max ;64.4 mL $kg $min ), ̇ VO2max compared with endurance train- whereas no changes in these measures ferences between groups in measures of ing alone (25). were observed in the endurance only strength (1RM), power (CMJ height), and endurance performance (85). Con- Previous research has shown that endur- group (59). The LFHV strength training sidering there is a delay between when ance athletes who strength train with involved various plyometric exercises a training stimulus is implemented and loads .70% 1RM exhibit larger changes and short sprints (20–100 m), which the subsequent effects on perfor- in movement economy and endurance suggests that although the absolute bar- mance (90), a sequenced approach performance than endurance athletes bell loads during strength training ses- may be more appropriate than trying who strength train with lighter loads sions were relatively light, the forces to improve strength, power, and endur- (36,48,73). Sedano et al. (73) reported placed on the musculoskeletal system ance simultaneously (15,81). greater magnitudes of change in running were much larger than to what the ath- economy, countermovement jump letes were previously accustomed. TRAINING THEORY (CMJ) height, vV̇O2max, and 3-km Considering that gaining body mass is time trial performance after 12 weeks a concern for endurance athletes, one THE TRAINING PROCESS of heavy strength training (.70% of the purported benefits of LFHV The primary goals of any successful 1RM) compared with lighter strength strength training is the lower degree training program are to reduce the likeli- training (,40% 1RM) and a control of muscle hypertrophy compared with hood of injury and optimize perfor- group (circuit training) in Spanish HFLVstrength training (28,70), but still mance (81). Before designing a training

Strength and Conditioning Journal | www.nsca-scj.com 3 4 teghTann o nuac Athletes Endurance for Training Strength Table 1 Effects of concurrent HFLV strength training and endurance training on HIEE and LIEE OUE3 UBR2|ARL2015 APRIL | 2 NUMBER | 37 VOLUME Study Athletes V̇O2max Strength training HIEE LIEE (mL$kg21$min21) HFLV ST Støren et al. (82) 17 M and F well-trained 59.9 4 3 4RM, 33’s/wk for 8 wk — 21.3% increase in TE at MAS runners

Jackson et al. (39) 23 M and F cyclists with 52 4 3 4RM, 33’s/wk for 10 wk NS for vV̇O2max NS for 30-km TT .0.5 y competing Levin et al. (45) 14 M cyclists with .1y 62.8 4 3 5RM, 33’s/wk for 6 wk Control . ST for PP during NS for 30-km TT competing (HFLV) last 1-km sprint

Rønnestad et al. 20 M and F well-trained 66.4 4–10RM, 23’s/wk for 12 wk 4.2% increase in Wmax 7% increase in MP during ﬁnal (66) cyclists 5 min of 185 min TT Rønnestad et al. 20 M and F national 66.4 4–10RM, 23’s/wk for 12 wk 9.4% increase wingate PP, 6% increase in MP during 40-min (64) level cyclists 4.3% increase in Wmax TT

Rønnestad et al. 12 M and F national 66.3 4–10RM, 23’s/wk for 25 wk 8% increase in Wmax , — (65) level cyclists increase wingate PP Rønnestad et al. 17 M national/ 66.2 3–5 3 4–8, 4–5 3 3–5RM, 23’s/ — NS in 7.5-km rollerski TT (68) international cross- wk for 12 wk country skiers

Rønnestad et al. 16 M national/ 75.5 4–10RM, 23’s/wk for 10 wk, 3% increase in Wmax , 6.5% increase in MP during (67) international cyclists 13/wk for 15 wk earlier peak torque in 40 min TT pedal stroke Sunde et al. (83) 13 M and F competitive 61.1 4 3 4RM, 33’s/wk for 8 wk — 17.2% increase TE at MAP cyclists Aagaard et al. (2) 14 M international level 72.5 3 3 12, 3 3 10, 3 3 8, 2–3 3 — 8% increase in 45-min TT cyclists 6RM, 2–33’s/wk for 16 wk

Hoff et al. (36) 15 F cross-country 55.3 3 3 6RM (pulldowns), 33’s/wk — 137% increase in TE at Wmax skiers, trained for 9 wk 8.8 h/wk

Hoff et al. (35) 19 M well-trained cross- 69.4 3 3 6RM (pulldowns), 45 min/wk — 56% increase in TE at vV̇O2max country skiers for 8 wk

Østera˚s et al. (58) 19 M well-trained cross- 61.2 3 3 6RM (pulldowns), 45 min/wk — 61% increase in TE at vV̇O2max country skiers with for 9 wk .5 y competing program, however, the coach and the 5

low- athlete must understand that training is

5 acomprehensiveprocessthatharmo- nizes a myriad of factors to foster athlete development. Figure 1 depicts some of these factors that affect athletic perfor-

control for 3 km TT mance. Therefore, the sport coaches,

. strength and conditioning staff, and sports medicine professionals each play no statistical change; OBLA LFHV 0.05) an important role within their own dis- 5 . , ciplines to contribute to an athlete’s low force high velocity; LIEE P ( control for men, butcontrol better for than women poling TT, increase induring W/kg 5-min double poling hour of 2-h cycling test

5 development. In addition, the manage- HFLV Mean 5k times were worse than 7% increase in 1.1-km double ment of external stressors in the athlete’s daily life is also an important component max — 2

mean power; NS in the optimization of performance. O ̇ max 2 5 maximal velocity in maximal anaerobic running test; To achieve this objective, however, train- O ̇ max (ES: 2 5 O ̇ ing variables must be integrated in

MART asequenceoverthecourseofthetrain- ing process (79). The training process is traditionally organized into 3 basic 0.87) 5-jump test, 1.6% increase in vV 100 m velocity during sprint roller skiing levels: macrocycles, mesocycles, and 10% increase in PF during 6.7% increase in vOBLA — NS in 20, 40, 60, 80, and 2.6% increase in vV increase in vV microcycles (79). A macrocycle is

3 along-durationtraining cycle, typically movement economy; MP high-intensity exercise endurance; LFHV ’s/wk 5

4–8, 2 classiﬁed as 12 months of training, which 3 5 8, 3

3 are composed of multiple mesocycles. time trial performance; V 3

5 Mesocycles are moderate-length periods 5RM, 2 ’s/wk for 5 wk — Maintenance of FCC during last 7 at 70% 1RM, of training, which can focus on develop- 5–10, 4 3 ’s/wk for 12 wk ’s/wk for 4 wk 3 ’s/wk for 7/10 wk 5–8, 4 3 ing speciﬁc ﬁtness characteristics within 3 3 3 3 3

5, 5 the macrocycle. Finally, each mesocycle Table 1

3 is composed of shorter training periods (continued) 6RM, 2 3–5RM, 3 6–15, 4

’s/wk for 12 wk (HFLV referred to as microcycles (79). The tool 3–6RM, 2 6–10, 3 5, 4 3 3 3 3 3 (HFLV group) 4–6RM, 1–2 (HFLV group) for 14 wk 2 group) maximal aerobic speed; ME used to structure each phase of training 3 3 time to exhaustion; TT 5 high force low velocity; HIEE within a macrocycle is referred to as an 5 5 “annual training plan” (15). More speciﬁcally, the annual plan is along-termtrainingtemplateusedto max. 2 64.7 3 61.9 3–4 69.2 3–5 63.8 2–4 68.7 3 69.5 Leg exercises 3 O ̇ guide the coach and athlete in the

peak power; TE design and implementation of vari- 5 ous training phases (15). The annual training plan can be separated into

maximal aerobic power; MAS phases: the general preparatory phase, peak power at V 5 competitive phase, peak phase, and 5 peak force; PP active rest (Figure 2). For a detailed 5 max

freely chosen cycling cadence; HFLV description of each phase, the reader 5

male; MAP is encouraged to examine the work of

5 Bompa and Haff (15). level cross-country skiers level runners level triathletes cross-country runners level triathletes runners 19 M and F national 16 M regional/national 14 M regional/national

female; FCC PERIODIZATION 5 To reduce the likelihood of injury and maximize athletic performance, strength and conditioning professionals should maximal oxygen uptake; W

5 organize training adaptations in a logical effect size; F (46) (26) (31)

5 manner to minimize fatigue and high- max Losnegard et al. Guglielmo et al. Hausswirth et al. Barnes et al. (7) 42 M and F collegiate Millet et al. (51) 15 elite/international Sedano et al. (73) 18 M national level 2 ES O ̇ light technical and ﬁtness characteristics onset of blood lactate accumulation; PF intensity exercise endurance; M V (e.g., strength, speed, endurance, etc.) at

Strength and Conditioning Journal | www.nsca-scj.com 5 6 teghTann o nuac Athletes Endurance for Training Strength OUE3 UBR2|ARL2015 APRIL | 2 NUMBER | 37 VOLUME

Table 2 Effects of concurrent LFHV strength training and endurance training on HIEE and LIEE

Study Athletes V̇O2max Strength training HIEE LIEE (mL$kg21$min21) LFHV ST Paavolainen 18 M elite cross- 67.7 Jumps (unilateral and bilateral, drop, hurdle), short 3.4% increase in 20-m 5.1% increase in et al. (59) country runners sprints (20–100 m), 5–20 reps/set at 0–40% 1RM velocity, increased VMART 5-km TT for 9 wk (P , 0.05) Spurrs et al. (74) 17 M trained runners 57.6 Plyometric drills, progressed from 60–180 — 2.7% increase in contacts, 23’s/wk for 6 wk 3-km TT Mikkola et al. 25 M and F, high 62.1 Short sprints (30–150 m), 2–3 3 6–10, 33’s/wk NS 1.2% increase in — (48) school runners for 8 wk vV̇O2max, 3% increase in VMART

Berryman et al. 28 M provincial 56.9 Drop jumps and concentric squat jumps, 13/wk Increase in vV̇O2max Increase in 3-km TT (12) standard runners for 8 wk (ES: 0.43) (ES: 0.37)

Bastiaans et al. 14 M competitive — 2–4 3 30, squats, leg press/pull, step-ups, 4.7% increase in Wmax 7.9% increase in (9) cyclists (.6 y) midsection 33’s/wk for 9 wk 60 min TT Mikkola et al. 19 M national cross- 66.5 Double pole sprints (10 3 10 s), leg exercises 3 3 NS 2-km poling velocity, — (50) country skiers 6–10, sprints, jumps, pogos, 33’s/wk for 8 wk 1.4% increase in 30-m double poling

Guglielmo et al. 16 M regional/ 61.9 3–4 3 12RM, 23’s/wk for 4 wk 1% increase in vV̇O2max — (26) national level runners

Sedano et al. 18 M national level 69.5 Leg exercise 3 3 20 at 40% 1RM, 23’s/wk Increase in vV̇O2max Small improvement (73) runners for 12 wk (ES: 0.61) in 3k TT (P , 0.05)

ES 5 effect size; F 5 female; FCC 5 freely chosen cycling cadence; HFLV 5 high-force low velocity; HIEE 5 high-intensity exercise endurance; LFHV 5 low force high velocity; LIEE 5 low-intensity exercise endurance; M 5 male; MAP 5 maximal aerobic power; MAS 5 maximal aerobic speed; ME 5 movement economy; MP 5 mean power; NS 5 no statistical change; OBLA 5 onset of blood lactate accumulation; PF 5 peak force; PP 5 peak power; ST 5 strength training; TE 5 time to exhaustion; TT 5 time trial performance; VMART 5 maximal velocity in maximal anaerobic running test; V̇O2max 5 maximal oxygen uptake; Wmax 5 peak power at VȮ 2max. defined as, “The strategic manipulation of an athlete’s preparedness through the employment of sequenced training phases defined by cycles and stages of workload” (22). Furthermore, if the training stimuli are sequenced appropriately, each phase of training will enhance or “potentiate” the next training phase (15,79,81). This concept, referred to as phase potentiation, is essential in the development of endurance-specific performance characteristics.

THE IMPORTANCE OF POWER IN ENDURANCE SPORTS The development of high-power out- Figure 1. Factors affecting athletic performance, modified from Stone et al. (81). Adapted, with permission, from M.H. Stone, M. Stone, and W.A. Sands, puts and high RFDs are vital to suc- 2007, Principles and practice of resistance training (Champaign, IL: Human cess in most sporting events (76) and Kinetics), 203. can differentiate levels of athletic performance (5,6,29). Maximal power output and RFD have conventionally been precise times of the training year “to physiological adaptations is referred to viewed as fitness characteristics that increase the potential to achieve spe- as periodization. Although varying defi- are less important for endurance sports. cific performance goals” (79). This pro- nitions of this term have been proposed, This is misguided, however, because cess of chronologically manipulating periodization has been most recently there is evidence indicating that

Figure 2. Cross-country runner macrocycle.

Strength and Conditioning Journal | www.nsca-scj.com 7 Strength Training for Endurance Athletes

average power output over the course of training effects, seems to be directly training phase is vital in the facilitation of a long-distance race and maximal proportional to the length of the training of the desired physiological response. power output during the final sprint period (81,94). Consequently, proper For endurance athletes with limited may be critical factors determining sequencing of training phases with strength training experience, a traditional the outcome of the event (56,58,80). appropriate durations will enhance fit- model is appropriate (79,81). These ath- ness characteristics from prior stages letes should begin with building a neuro- THE IMPORTANCE OF STRENGTH of training and make them more resil- muscular base using HFLV strength IN THE DEVELOPMENT OF POWER ient to decay. In addition, the subse- training, and after a certain strength level Power is defined as “the rate of doing quent training phase can be redirected is achieved, LFHV strength training can work” (40) and is quantitatively ex- to focus on another fitness characteristic then be implemented (10). This is sup- pressed as power 5 force 3 velocity to further the athlete’s preparedness and ported by evidence indicating that (55). Therefore, an athlete can either dissipate accumulated fatigue from the among well-trainedathletes,LFHVis achieve greater power outputs by previous training cycle (81). necessary to make further alterations increasing the force production or by Although there are a number of sche- in the high-velocity end of the force- increasing the shortening velocity capa- matics to choose from when manipulat- velocity curve (30,77). Thus, HFLV and bilities of skeletal muscle. It is important ing these variables, a traditional model LFHV strength training are both impor- to note, however, that skeletal muscle fits the previously described sequence tant components in the endurance ath- shortening velocities are limited by the of strength and power development lete’s strength and conditioning program activity of myosin ATPase, which ulti- (79,81). During the general preparation provided they are included at the appro- mately dictates the rate of cross-bridge phase, higher volumes of strength train- priate time and in the correct sequence cycling through ATP dissociation (57). ing should be used to enhance work (Figure 2). Accordingly, this elucidates the vital role capacity and increase lean body mass Regarding high-level endurance ath- of maximal strength in the development (15). Despite concerns over increases in letes, however, the use of a traditional of power (76). Simply put, an increased body mass, for many endurance athletes, model with a single peaking phase is ability to produce force provides the ath- the general preparation phase is one of often impractical, as most athletes will lete with the opportunity to enhance the few times during the annual plan compete in multiple significant events power production. where small increases in muscle hyper- throughout the course of a competitive trophy can be achieved. This in turn will season. Accordingly, manipulating vol- TRAINING SEQUENCING FOR THE ENDURANCE ATHLETE potentiate gains in maximal strength and ume and intensity to produce specific power in subsequent phases of training. physiological adaptations must coincide SEQUENCE AND DURATION OF As the athlete progresses from the gen- with this competitive schedule (80). TRAINING PHASES eral preparation period to the specific Unlike the traditional model, after the Originally proposed by Stone et al. (78), preparation and competition phases of athlete completes the peaking phase strength and power should be developed the macrocycle, strength training volume and competes in a key event of the sea- by cycling 4 distinct phases of training: is progressively diminished while training son, further planning will be necessary to strength-endurance, basic strength, intensity increases, as strength and power prepare the athlete for future competi- strength, and power (78). This model become the primary fitness characteris- tions of importance (80,81). More spe- of strength and power development, in tics of interest, respectively (38). Before cifically, if adequate time exists before addition to the concept of phase poten- aculminatingeventinthecompetitive the next major event, strength training tiation, has since been supported by season (e.g., championship race), the volume may be increased to re-establish further evidence (30,52,93) and is also peaking phase or taper requires “a reduc- strength levels (63,79). Conversely, if referred to as block periodization (38) tion of the training load during a variable time is insufficient, strength training vol- or the conjugate-sequencing system period of time, in an attempt to reduce ume should be increased cautiously to (90). A 4-week training phase has been the physiological and psychological stress avoid undue fatigue before the next con- previously suggested, using the first 3 of daily training and optimize perfor- test (63,80,81). weeks to progressively load the ath- mance” (53). After the peaking phase, lete, and the final week as an unload- the athlete transitions into the off- EXERCISE SELECTION FOR THE ENDURANCE ATHLETE ing period to modulate recovery season with a period of active rest con- (15,63,81). Although the duration of sisting of recreational activities in which When selecting exercises for specific the phase is dependent on the relative both intensity and volume are reduced phases of training, it is important for training intensity, training volume, time and recovery is the objective (81). practitioners and athletes to consider of the season, needs of the athlete, and the transfer of training effect. That is, other external factors. Regardless of the TRAINING VOLUME AND the degree of performance adaptation length of each training cycle, however, it INTENSITY that can result from a training exercise is important for practitioners to remem- The selection of appropriate training (11,81). Therefore, choosing exercises ber that the rate of decay, or involution volumes and intensities within each with similar movement patterns and

8 VOLUME 37 | NUMBER 2 | APRIL 2015 kinetic parameters (e.g., peak force, athletes with more strength training Heather A. RFD, acceleration, etc.) will result in experience, a sequenced approach Abbott is cur- a greater transfer to performance (11). (e.g., block periodized model) may rently completing Although some endurance sport move- be more appropriate than trying to her PhD at East ments have both closed and open improve strength, power, and endur- Tennessee State kinetic chain sequences, in movements ance simultaneously. University with such as running, closed kinetic chain A limitation to the current research the Department exercises should be prioritized as they exists in the design and implementa- of Exercise and have been suggested to require greater tion of training protocols. Some stud- Sport Science in levels of intermuscular coordination ies comparing different strength conjunction with the Center of Excellence (76) and result in greater performance training modalities fail to control for for Sport Science and Coach Education. enhancement compared with open differences in strength and endurance chain movements (62,75). Traditional training volume between experimental squatting and weightlifting movements conditions. Another limitation, only Christopher R. are primary examples. Moreover, squat controlled for in a few studies, is the Bellon is cur- strength has been strongly correlated to addition of strength training without rently completing athletic movements that require rela- a simultaneous reduction in the vol- his PhD at East tively high-velocity, high-power outputs ume of endurance training. Practically, Tennessee State and RFD (6,18). Weightlifting exercises if applied in an athletic setting, this University with and their derivatives have also shown could result in poor fatigue manage- the Department a strong transfer of training to such ment and an increased risk of of Exercise and movements as well (4,16,37). Practically, overtraining syndrome. The imple- Sport Science in these exercises may assist with passing mentation of an annual training plan conjunction with the Center of Excellence an opponent, enhancing movement where endurance and strength training for Sport Science and Coach Education. economy, increasing average power out- variables are carefully manipulated will put, and sprinting the final 100 m of maximize athletic performance while arace(56,58,80).Consideringtheessen- reducing injury risk by more appropri- Christopher B. tial role that these exercises play in the ately managing training volume. Taber is currently development of strength and power and Future research should examine the completing his subsequent effects on HIEE and LIEE, effectiveness of monitoring programs PhD at East squatting and weightlifting movements in determining when to manipulate Tennessee State should be staples throughout the training training variables throughout a macro- University with year for endurance athletes. cycle and the subsequent effects on the Department endurance performance. of Exercise and PRACTICAL APPLICATIONS Sport Science in conjunction with the Conflicts of Interest and Source of Funding: Previous research on concurrent train- Center of Excellence for Sport Science The authors report no conflicts of interest ing for endurance athletes suggests and Coach Education. that maximum strength is associated and no source of funding. with endurance factors, a relationship ACKNOWLEDGMENTS that is likely stronger for HIEE activi- The authors thank Jacob Goodin for Michael H. Stone is the Laboratory ties than for LIEE. HFLV strength his corrections and editorial comments Director and PhD Coordinator in the training can affect increases in HIEE in preparation of this article. Center of Excellence for Sport Science and LIEE through increasing peak and Coach Education/Department of force and RFD. LFHV strength training Exercise and Sport Science at East Ten- has also been reported to elicit improve- Caleb D. nessee State University. ments in HIEE and LIEE performance, Bazyler is cur- however, not all studies agree. When rently completing considering findings from studies his PhD at East REFERENCES examining changes in endurance per- Tennessee State 1. Aagaard P and Andersen JL. Effects of formance and related measures after University with strength training on endurance capacity in top-level endurance athletes. Scand J Med strength training, it seems that concur- the Department Sci Sports 20(Suppl 2): 39–47, 2010. rent HFLV strength and endurance of Exercise and 2. Aagaard P, Andersen JL, Bennekou M, training may provide superior results Sport Science in Larsson B, Olesen JL, Crameri R, compared with LFHV strength and conjunction with Magnusson SP, and Kjaer M. Effects of endurance training for relatively weak the Center of Excellence for Sport Science resistance training on endurance capacity endurance athletes. For endurance and Coach Education. and muscle fiber composition in young

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