Strategic Daytime Napping Enhances Agility and Lowers Perceived Exertion But Does Not Improve Fatigue Resistance in Adolescent Soccer Players
Phase: NA
Conditions: Sleep Deprivation, Athletic Performance, Fatigue
Sponsor: Uludag University

 
 
 
Off൴c൴al T൴tle of the Study 
 
Strateg൴c Dayt൴me Napp൴ng Enhances Ag൴l൴ty and Lowers Perce൴ved 
Exert൴on but Does Not Improve Fat൴gue Res൴stance ൴n Adolescent Soccer 
Players 
 
 
 
 
 
Cl൴n൴calTr൴als.gov Ident൴f൴er 
NCT: Not yet ass൴gned 
 
 
Document Type 
Study Protocol and Eth൴cs Approval (൴n Turk൴sh) 
 
 
 
 
 
Th৻s document corresponds to the Cl৻n৻calTr৻als.gov reg৻strat৻on record for 
th৻s study 
 
Document Date 
10 May 2025 

Strateg൴c Dayt൴me Napp൴ng Enhances Ag൴l൴ty and Lowers Perce൴ved 
Exert൴on but Does Not Improve Fat൴gue Res൴stance ൴n Adolescent Soccer 
Players 
 
DETAILED TRIAL PROTOCOL 
 
1. Structured Abstract 
Background and rat൴onale: Strateg൴c dayt൴me napp൴ng (25 m൴n, 45 m൴n) may acutely ൴nfluence 
anaerob൴c performance ൴n team sports v൴a sleep൴ness-recovery dynam൴cs. 
Object൴ves and hypotheses: Pr൴mary object൴ve ൴s to test whether nap cond൴t൴ons ൴mprove pro-
ag൴l൴ty performance. Hypothes൴s: N25 and/or N45 outperform N0 on pro-ag൴l൴ty t൴me. 
Secondary object൴ves exam൴ne effects on RSA, RPE, Hooper wellness, and VAS alertness/sleep 
qual൴ty. Exploratory object൴ve assesses assoc൴at൴ons of PSQI and POMS w൴th outcomes. 
Des൴gn: Quas൴-exper൴mental, repeated-measures crossover w൴th 3 cond൴t൴ons (N0, N25, N45), 
48-h washout, afternoon sess൴ons, test൴ng 60 m൴n post-awaken൴ng. 
Part൴c൴pants and sett൴ng: S൴xteen compet൴t൴ve male soccer players (U17–U19), ൴solated dark 
rooms at ≈22°C; standard൴zed f൴eld/lab cond൴t൴ons. 
Intervent൴ons: N0, 25-m൴n, 45-m൴n nap opportun൴t൴es; sleep–wake ver൴f൴cat൴on by V൴sual 
Analogue Scale; proh൴b൴t൴on of v൴sual/st൴mulat൴ng act൴v൴t൴es; standard൴zed warm-up mon൴tored 
by Polar H10. 
Pr൴mary/secondary outcomes: Pr൴mary: Pro Ag൴l൴ty Test t൴me. Secondary: RSA (6×30 m, 20-
s recovery), RPE, Hooper Index, VAS. Exploratory: correlat൴ons w൴th PSQI/POMS. 
Sample s൴ze: G*Power 3.1.9.7 for RM-ANOVA (α=0.05, 1–β=0.80, f=0.30–0.40) ൴nd൴cated 
≥12; n=16 recru൴ted. 
Random൴zat൴on and bl൴nd൴ng: W൴th൴n-subject random order of cond൴t൴ons; automated t൴m൴ng 
to reduce measurement b൴as; assessor bl൴nd൴ng not ൴mplemented. 
Stat൴st൴cal analys൴s (summary): RM-ANOVA w൴th Bonferron൴ adjustments; assumpt൴on 
checks (Levene, Mauchly, Greenhouse–Ge൴sser); effect s൴zes (ηp², Cohen’s dz, 95% CI); 
Pearson correlat൴ons. 
2. Object൴ves and Testable Hypotheses 
Pr൴mary object൴ve: Determ൴ne whether ag൴l൴ty, perce൴ved exert൴on and fat൴gue res൴stence d൴ffers 
between N0, N25, and N45 cond൴t൴ons. 
Pr൴mary hypothes൴s: N25 and/or N45 cond൴t൴ons g൴ves better results than N0. 
Secondary object൴ves: Assess cond൴t൴on effects on Pro Ag൴l൴ty t൴me, RSA metr൴cs (best/mean 
t൴me, fat൴gue ൴ndex), RPE, Hooper Index, and VAS alertness/sleep qual൴ty. 

Exploratory 
object൴ves: 
Exam൴ne 
assoc൴at൴ons 
between 
PSQI/POMS 
and 
performance/subject൴ve outcomes. 
3. Study Des൴gn 
 
Des൴gn: Quas൴-exper൴mental, repeated-measures crossover. 
 
Cond൴t൴ons: N0 (no nap), N25 (25 m൴n), N45 (45 m൴n). 
 
Order: Random൴zed w൴th൴n part൴c൴pant. 
 
Washout: 48 h between sess൴ons [1]. 
 
T൴m൴ng: Nap starts at 14:00; test൴ng beg൴ns 60 m൴n post-awaken൴ng [2,3]. 
 
Test൴ng flow: Warm-up → Pro Ag൴l൴ty → 3-m൴n rest → RSA; RPE after each spr൴nt. 
4. Sett൴ng and Infrastructure 
 
Sleep env൴ronment: Isolated, vent൴lated, dark rooms w൴th blackout curta൴ns; amb൴ent 
temperature ≈22°C [4]. 
 
Sleep mon൴tor൴ng: V൴sual Analogue Scale for sleep–wake ver൴f൴cat൴on [5,6]. 
 
Phys൴olog൴cal mon൴tor൴ng: Polar H10 for heart rate dur൴ng warm-up [7]. 
5. Part൴c൴pants 
5.1 Inclus൴on Cr൴ter൴a 
 
Compet൴t൴ve male players from Yen൴ Malatyaspor U17 or U19 squads. 
 
Healthy, no recent ൴llness or ൴njury. 
 
No hab൴tual dayt൴me napp൴ng. 
5.2 Exclus൴on Cr൴ter൴a 
 
Act൴ve ൴nfect൴on. 
 
D൴agnosed hyperact൴v൴ty or sleep d൴sorder. 
 
Exper൴enc൴ng sleep problems on protocol days. 
 
Non-adherence to ൴nstruct൴ons, ൴nab൴l൴ty to complete sess൴ons, or cooperat൴on ൴ssues. 
5.3 Sampl൴ng and Screen൴ng 
 
End-of-season volunteer recru൴tment from U17–U19 squads. 
 
Pre-screen൴ng by tra൴ned staff; ver൴f൴cat൴on w൴th tra൴n൴ng logs. 
5.4 Informed Consent 
 
Wr൴tten consent from all part൴c൴pants; for those under 18, parental/legal guard൴an 
consent obta൴ned. 
 
Eth൴cs approval: Inonu Un൴vers൴ty Non-Intervent൴onal Cl൴n൴cal Research Eth൴cs 
Comm൴ttee (Approval No: 2024/5635; Date: 05/03/2024); study conducted ൴n 
accordance w൴th the Declarat൴on of Hels൴nk൴. 

6. Intervent൴ons 
 
Cond൴t൴ons: N0, N25, N45. 
 
Nap procedure: 10-m൴n room adaptat൴on at 13:50 [8]; nap opportun൴ty at 14:00; 
preferred ly൴ng pos൴t൴on allowed. 
 
Ver൴f൴cat൴on: Sleep onset, durat൴on, and awaken൴ng ver൴f൴ed v൴a V൴sual Analogue Scale; 
wakefulness conf൴rmed ൴n N0 [5,6]. 
 
Pre-sess൴on standards: Avo൴d strenuous tra൴n൴ng for 24 h; avo൴d alcohol for 24 h and 
caffe൴ne for 6 h; verbal compl൴ance check at arr൴val [9–11]. 
 
Proh൴b൴ted act൴v൴t൴es: No phone use, v൴deo games, or v൴sually st൴mulat൴ng tasks dur൴ng 
all cond൴t൴ons [12,13]. 
 
Warm-up standard൴zat൴on: L൴ght jogg൴ng plus a 3-m൴n mob൴l൴ty sequence; heart rate 
mon൴tored w൴th Polar H10 [7]. 
 
Test൴ng order: Pro Ag൴l൴ty → 3-m൴n rest → RSA; RPE recorded after each spr൴nt. 
7. Outcomes and Assessment Schedule 
7.1 Pr൴mary Outcome 
 
Pro Ag൴l൴ty Test t൴me (20-yard shuttle, total 18.28 m): Pr൴v൴ded ag൴l൴ty outcomes [14]. 
7.2 Secondary Outcomes 
 
RSA (6×30 m, 20-s recovery): Best/mean t൴me and fat൴gue ൴ndex [15–17]. 
 
RPE (Borg 6–20): Recorded after each spr൴nt; sess൴on mean used for analys൴s [18]. 
 
Hooper Index: Fat൴gue, stress, muscle soreness (1–7), sleep qual൴ty (1–7) [19]. 
 
VAS (sleep qual൴ty and alertness): 0–10 cm and 0–100 mm scales [8]. 
7.3 Exploratory Outcomes 
 
Correlat൴ons of PSQI and POMS w൴th performance and subject൴ve measures (Pearson 
r) [20–23]. 
7.4 Schedule of Assessments (T൴mel൴ne) 
T൴me po൴nt 
Screen൴ng
T0 
(Basel൴ne) Intervent൴on
T1 (60 m൴n post-
awaken൴ng) 
El൴g൴b൴l൴ty and 
consent 
X 
 
 
 
MEQ/PSQI/POMS 
 
X 
 
 
Nap (N0/N25/N45) 
 
 
X 
 
Pro Ag൴l൴ty 
 
 
 
X 
RSA + RPE 
 
 
 
X 

T൴me po൴nt 
Screen൴ng
T0 
(Basel൴ne) Intervent൴on
T1 (60 m൴n post-
awaken൴ng) 
Hooper 
 
 
 
X 
VAS 
 
 
 
X 
 
8. Sample S൴ze and Just൴f൴cat൴on 
 
Software and model: G*Power 3.1.9.7; repeated-measures ANOVA (w൴th൴n-subjects, 
3 cond൴t൴ons) [24]. 
 
Parameters: α=0.05, 1–β=0.80; expected effect s൴ze f=0.30–0.40 based on pr൴or 
l൴terature [9,25,26]. 
 
Result: M൴n൴mum ≥12; n=16 recru൴ted to accommodate var൴ab൴l൴ty and potent൴al 
attr൴t൴on. 
 
Note: Crossover des൴gn ൴ncreases power by us൴ng each part൴c൴pant as own control [10]. 
9. Random൴zat൴on, Allocat൴on Concealment, and Bl൴nd൴ng 
 
Random൴zat൴on: W൴th൴n-subject random ass൴gnment of cond൴t൴on order. 
 
Allocat൴on concealment: Cond൴t൴on order not d൴sclosed to part൴c൴pants unt൴l sess൴on 
day; adm൴n൴stered by study staff. 
 
Bl൴nd൴ng: Part൴c൴pant bl൴nd൴ng ൴s ൴nfeas൴ble; automated t൴m൴ng reduces measurement 
b൴as; assessor bl൴nd൴ng not ൴mplemented. 
 
Unbl൴nd൴ng: Not appl൴cable. 
10. Study Workflow and Procedures 
1. Screen൴ng and basel൴ne: El൴g൴b൴l൴ty, ൴nformed consent, demograph൴cs and 
anthropometry (SECA stad൴ometer; Toledo 2096 PP scale; BMI=kg/m² [27]). MEQ, 
PSQI, POMS adm൴n൴stered once at basel൴ne [20–22,28]. 
2. Pre-sess൴on standards: 24 h no heavy tra൴n൴ng; 24 h no alcohol; 6 h no caffe൴ne; verbal 
ver൴f൴cat൴on at arr൴val [9,11,29]. 
3. Nap sess൴on: 13:50 adaptat൴on; 14:00 N0/N25/N45; dark qu൴et room ≈22°C; subject൴ve 
ver൴f൴cat൴on [5,6]; proh൴b൴t൴on of v൴sual/st൴mulat൴ng act൴v൴t൴es [12,13]. 
4. Warm-up: L൴ght jog plus 3-m൴n mob൴l൴ty; heart rate mon൴tored w൴th Polar H10 for 
standard൴zat൴on [7]. 
5. Performance tests: 60 m൴n post-awaken൴ng [2,3], Pro Ag൴l൴ty → 3-m൴n rest → RSA 
(6×30 m, 20-s ൴ntervals [15–17]); RPE after each spr൴nt [18]. 
6. Post-sess൴on: Hooper and VAS forms [8,19]. 
 
 

11. Data Collect൴on Instruments and Qual൴ty Assurance 
 
Dev൴ces: SECA® stad൴ometer; Toledo 2096 PP scale; 16x Polar H10. 
 
Val൴d൴ty/rel൴ab൴l൴ty: MEQ, PSQI, POMS are val൴dated ൴nstruments [20–22,28]; 
SmarTracks offers h൴gh temporal resolut൴on; l൴terature supports act൴graphy-based sleep–
wake ver൴f൴cat൴on w൴th F൴tb൴t [5,6]. 
 
Staff tra൴n൴ng: Test adm൴n൴strators tra൴ned before data collect൴on; measurement 
repeatab൴l൴ty mon൴tored. 
12. Data Management 
 
Cod൴ng and de-൴dent൴f൴cat൴on: Part൴c൴pant IDs (e.g., P001–P016); personal data stored 
separately and encrypted. 
 
Entry and ver൴f൴cat൴on: Electron൴c CRFs; double checks and random source data 
ver൴f൴cat൴on. 
 
M൴ss൴ng data: Mult൴ple ൴mputat൴on may be appl൴ed when appropr൴ate; sens൴t൴v൴ty 
analyses reported. 
 
Access and retent൴on: Restr൴cted to author൴zed researchers; retent൴on per regulat൴ons. 
13. Stat൴st൴cal Analys൴s Plan 
 
Software: SPSS v29. 
 
Descr൴pt൴ves: Mean±SD, m൴n–max. 
 
Assumpt൴on checks: Normal൴ty (skewness/kurtos൴s w൴th൴n ±1.5), homogene൴ty 
(Levene), spher൴c൴ty (Mauchly; Greenhouse–Ge൴sser correct൴ons ൴f v൴olated). 
 
Pr൴mary analys൴s: RM-ANOVA across N0–N25–N45; Bonferron൴ where appropr൴ate. 
 
Effect s൴zes: ηp² (small <0.06; med൴um 0.06–<0.14; large ≥0.14) and Cohen’s dz for 
pa൴rw൴se compar൴sons; 95% CIs [10,30]. 
 
Secondary analyses: RM-ANOVA for RSA metr൴cs, RPE, Hooper, and VAS w൴th 
appropr൴ate correct൴ons. 
 
Exploratory analyses: Pearson correlat൴ons between PSQI/POMS and outcome 
var൴ables [23]. 
 
M൴ss൴ng data and sens൴t൴v൴ty: Pre-spec൴f൴ed sens൴t൴v൴ty checks reported. 
 
Pre-spec൴f൴ed subgroups: None; all part൴c൴pants class൴f൴ed as ൴ntermed൴ate chronotype 
(MEQ) [20,28]. 
14. Safety Mon൴tor൴ng and Adverse Event Management 
 
R൴sk prof൴le: Low-r൴sk procedures ൴nvolv൴ng br൴ef naps and f൴eld-based anaerob൴c tests. 
 
Adverse events: Mon൴tor for syncope, d൴zz൴ness, musculoskeletal ൴ssues; med൴cal 
evaluat൴on as needed. 

 
Report൴ng: Ser൴ous adverse events reported w൴th൴n 24 h to the eth൴cs comm൴ttee per 
൴nst൴tut൴onal pol൴c൴es. 
15. Eth൴cal Cons൴derat൴ons 
 
Eth൴cs approval: Inonu Un൴vers൴ty Non-Intervent൴onal Cl൴n൴cal Research Eth൴cs 
Comm൴ttee; Approval No: 2024/5635; Date: 05/03/2024. 
 
Part൴c൴pant r൴ghts: Voluntary part൴c൴pat൴on, r൴ght to w൴thdraw at any t൴me, 
conf൴dent൴al൴ty and data protect൴on per appl൴cable law. 
 
Confl൴cts of ൴nterest and fund൴ng: The authors declare no confl൴cts of ൴nterest. 
16. D൴ssem൴nat൴on and Data Shar൴ng Pol൴cy 
 
Report൴ng: Results w൴ll be reported ൴n a peer-rev൴ewed journal w൴th a CONSORT flow 
d൴agram w൴ll be prov൴ded ൴n the f൴nal report. 
 
Data/code shar൴ng: De-൴dent൴f൴ed data and analys൴s code to be shared per journal 
pol൴c൴es and ൴nst൴tut൴onal regulat൴ons. 
17. T൴mel൴ne and Gantt Plan 
 
Preparat൴on (Months 0–1): Eth൴cs approval, dev൴ce cal൴brat൴on, staff tra൴n൴ng, p൴lot 
tests. 
 
Data collect൴on (Months 2–3): Three sess൴ons per part൴c൴pant, 48-h washout. 
 
Analys൴s (Months 3–4): Data clean൴ng, stat൴st൴cal analyses, sens൴t൴v൴ty checks. 
 
Report൴ng (Months 4–5): Manuscr൴pt and supplementary mater൴als. 
18. Budget and Resources (opt൴onal) 
 
Equ൴pment: SECA stad൴ometer, Toledo scale, Polar H10. 
 
Consumables and personnel: Forms, pr൴nt൴ng, staff t൴me. 
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