| Alashti
et al., 2021 |
2v2; 4v4 |
Blood samples
pre and immediately post SSG |
GH: significant
increase post in both groups (2v2, p < 0.001; 4v4, p < 0.003).
IGF-1: significant increase post in both groups (p < 0.001). ANOVA
showed group effect for GH (F = 9.113, p = 0.0014), IGF-1 (F = 11.34, p
= 0.0005). Lactate increased significantly in both SSGs (p < 0.001),
~8-fold in 2v2 and ~7-fold in 4v4. Correlation: lactate positively
correlated with IGF-1 in 4v4 (r = 0.722, p = 0.43) but not with GH. |
| Bekris
et al., 2022 |
3v3 |
Blood samples
PRE, POST, 24 h, 48 h, 72 h |
IL-6 peaked
POST (3.52 ± 0.43 pg/mL) and returned to baseline by 24 h (F(1.04,11.50)=504.82,
p < 0.001, η2=0.98). CK peaked at 24 h (536.58
± 124.73 U/L) and remained elevated at 48 h and 72 h (F(1.76,19.32)=93.96,
p < 0.001, η2=0.90). Cortisol peaked POST (14.62
± 4.58 μg/dL), still elevated at 24 h, returned to baseline
48–72 h (F(1.00,11.00)=122.21, p < 0.001, η2=0.92).
Testosterone peaked POST (6.00 ± 1.55 ng/mL), normalized within 24
h (F(1.69,18.62)=47.39, p < 0.001, η2=0.81). T/C
ratio lowest POST (0.44 ± 0.16), returned to baseline by 24 h (F(1.73,19.05)=12.12,
p < 0.001, η2=0.52). |
| Bonato
et al., 2020 |
4v4 |
Salivary
cortisol PRE, POST, and morning after (CAR) |
PRE: 1.79
± 0.48 ng/mL → POST: 3.37 ± 1.42 ng/mL (p = 0.0003,
ES = 1.4, very large). CAR: 4.21 ± 0.60 ng/mL (p < 0.0001,
ES ≥ 2.0, very large). POST cortisol lower in SSG than HIIT (3.37
vs 5.63 ng/mL, p < 0.0001, ES ≥ 2.0). |
| Chmura
et al., 2019 |
1v1, six
× 30 s / 2 min rest (E1) vs six × 45 s / 3 min rest (E2),
10×15 m field |
Capillary
blood at rest, immediately post, +15 min, +30 min |
Total Testosterone
(TT): Significant effect of time (F(3,48)=15.26, p ≤ 0.0001). TT
peaked immediately post (E1: 5.50 ± 1.58; E2: 4.66 ± 0.94
ng/mL) vs rest and declined at +30 min (E1: 3.86 ± 1.14; E2:
3.62 ± 0.73). Large effect sizes: immediate vs 30 min (d=1.16), rest
vs 30 min (d=0.96). Free Testosterone (FT): Effect of time (F(3,48)=6.86,
p=0.0006). FT peaked post (E1: 14.77 ± 6.41 pg/mL; E2: 13.82 ±
3.67) then declined by +30 min (E1: 10.94 ± 5.23; E2: 11.60
± 2.45). Medium effect: post vs 30 min (d=0.66). Cortisol (C): Effect
of time (F(3,48)=11.16, p ≤ 0.0001). Post values ↑ vs rest
(E1: 189.76 ± 63.65 vs 147.39 ± 32.15 ng/mL; E2: 185.77 ±
46.68 vs 127.43 ± 38.56). In E1, C peaked at +15 min (251.40
± 80.55 ng/mL), higher than rest and post (d=1.70 and d=0.85). Ratios
(TT/C, FT/C): Significant time effects (TT/C F(3,48)=7.45, p=0.0003; FT/C
F(3,48)=5.11, p=0.0038). Ratios decreased 15–30 min post vs rest
(TT/C rest 0.035 ± 0.011 → 0.020 ± 0.014 at +15
min; FT/C rest 0.089 ± 0.033 → 0.058 ± 0.034 at +15
min). |
| Dello Iacono
et al., 2016 |
3v3 handball,
with vs without contact |
IL-6 pre
and immediately post |
IL-6 increased
46.1% after C-SSG (p<0.05), but not after NC-SSG (+16.5%,
p=0.12). Very strong correlation between number of contacts and IL-6 response
(r=0.971, p<0.001). |
| Johnston
et al., 2014 |
Rugby league,
“offside” 6v6 SSG (2×8 min halves, 70×30 m),
with vs without contact (16 × 10 s bouts/half) |
Whole blood
CK PRE, POST, 12 h, 24 h |
CK increased
in both games. Non-contact: peak POST (ES = 1.27), declined at 12 h (ES
= 0.78) and 24 h (ES = 0.95). Contact: continued to rise at 12 h (ES = 1.25)
and 24 h (ES = 1.64). At 24 h, contact CK increase (54 ± 32%) > non-contact
(22 ± 13%), ES = 0.86, likelihood = likely (82%). |
| Karadağ
et al., 2024 |
2v2, 4v4,
8v8 |
Blood lactate
pre, immediately post, 30 min post | RPE (Borg 6–20) post-training |
Intragroup:
Lactate significantly ↑ post vs pre (p<0.05), ↓ at
30 min vs post (p<0.05), but remained above pre (p<0.05).
2v2: 1.35 ± 0.26 → 11.65 ± 2.73 → 3.1 ±
1.03 mmol/L. 4v4: 1.47 ± 0.27 → 7.72 ± 1.89 →
2.38 ± 0.49. 8v8: 1.44 ± 0.25 → 6.22 ± 2.38
→ 2.09 ± 0.50. Intergroup: Post and 30-min values lower in
2v2 vs 4v4 & 8v8 (p<0.05). RPE significantly higher in 2v2
(17.0 ± 0.81) vs 8v8 (14.56 ± 0.96) and 4v4 (16.0 ±
0.53) vs 8v8 (p<0.05). No difference between 2v2 and 4v4 (p>0.05). |
| Kryściak
et al., 2023 |
1v1, 6×30
s vs 6×45 s |
Blood lactate,
pH, HCO3-, base excess (BE) at T0, T1–T6, T7,
T8 |
Lactate:
↑ significantly across bouts (F(8,144)=162.72, p≤0.0001, η2=0.90),
peaked T6 ~17 mmol/L, remained >pre at T8 (6.2 mmol/L). No group
effect (F(1,18)=0.01, p=0.923). pH: ↓ progressively (F(8,144)=101.9,
p≤0.0001, η2=0.85), returned to baseline by 30
min. HCO3-: Group effect (F(1,18)=8.84, p=0.008, η2=0.33).
Lower in 30 s SSGs from T2–T8 (e.g., T6: 12.3 vs 15.2 mmol/L, p=0.0007,
d=2.41). BE: ↓ significantly across time (F(8,144)=292.77, p≤0.0001,
η2=0.94), more negative in 30 s SSGs at T6 and T7 (-16.7
vs -13.9 mmol/L, p=0.046–0.010). |
| Mascarin
et al., 2018 |
4v4, 4×4
min |
CK and
LDH, Testosterone & cortisol, pre, 10 min, 24 h, 48 h, 72 h |
CK unchanged
10 min (+2.7%, trivial), ↓ progressively: 24 h -19.6%
(likely), 48 h -36.3% (likely), 72 h -53.2% (very likely).
LDH ↑ 10 min +19.2% (likely), ↓ by 24–72 h (-7.7%
to -13.5%); T and C unchanged at 10 min (<0.4%, trivial).
Both ↓ at 24 h (T -32.7%, C -32.6%, very likely), ↓
at 48 h (T -8.9%, C -14.5%, likely), returned to baseline
at 72 h. T/C ratio unchanged. |
| Mitrotasios
et al., 2021 |
4v4 +
2 GK, 6×4 min, 3-min passive rest, 30×20 m pitch, U20 elite
males |
Blood pre
vs immediately post |
Lipids:
No significant changes: T-C (171.9 → 162.5 mg/dL, p=0.20), HDL-C
(63.1 → 64.1, p=0.28), LDL-C (92.0 → 86.3, p=0.46), TG (83.6
→ 60.8, p=0.11). Enzymes: CK ↑ 22.9% (273.1 → 335.6
U/L, Z=-2.38, p=0.02, r=0.84), CK-MB ↑ 21.8% (10.9 →
13.3 U/L, Z=-2.54, p=0.01, r=0.90), LDH ↑ 9.6% (257.1 →
281.8 U/L, Z=-2.10, p=0.04, r=0.74). No significant changes in γ-GT,
ALT, AST (p=0.25–0.75). Hormones: Cortisol ↑ 65.1% (9.2 →
15.2 μg/dL, Z=-2.53, p=0.01, r=0.89). Testosterone ↓
-23.4% (432.4 → 331.4 ng/dL, Z=-2.52, p=0.01, r=0.89). |
| Papanikolaou
et al., 2021 |
4v4 vs
8v8 |
CK baseline,
24h, 48h, 72h |
CK ↑
24–72h in 4v4 (p=0.001–0.000). CK ↑ only 24h in 8v8
(p=0.011). Higher CK in 4v4 vs 8v8 at 48h (p=0.004) and 72h (p=0.009). Indicates
more muscle damage in high-density SSG. |
| Sansone
et al., 2019 |
3v3, offense/defense
× long/short |
Salivary
cortisol (C) & testosterone (T) pre vs post |
Cortisol:
Significant ↑ overall (pre 7.2 ± 0.7 ng/ml → post 11.4
± 0.8 ng/ml, p=0.001, η2=0.702). No interaction
effects. Testosterone: Increased after defense-long (159.3 ± 94.7
→ 251.8 ± 104.3 pg/ml, p=0.037, r=0.47). Decreased after offense-short
(260.5 ± 155.9 → 192.2 ± 152.9 pg/ml, p=0.028, r=0.49).
Stable in other conditions. |
| Sparkes
et al., 2018 |
4v4 +
GK, as above |
Blood lactate,
CK, Salivary testosterone (T), cortisol (C) at baseline, 0h, +2h,
+24h |
Lactate:
↑ at 0h (+1.3 mmol·L-1, ±0.5, large),
↓ at +2h (-0.5, ±0.2, small), back to baseline
at +24h (+0.1, trivial). CK: ↑ at 0h (+97 U·L-1,
±28, small), ↑ at +2h (+118, ±24, moderate),
↑ at +24h (+94, ±49, small). CK remained elevated
for 24h. T: ↑ at 0h (+20 pg·ml-1, ±29,
small), ↓ at +2h (-61, ±21, moderate), baseline
at +24h (+2, trivial). C: ↓ at 0h (-0.09 μg·dl-1,
±0.16, small), ↓ at +2h (-0.39, ±0.12,
large), ↓ at +24h (-0.12, ±0.11, small) |
| Sparkes
et al., 2020a |
4v4 +
GK, as above |
CK, Salivary
testosterone, cortisol at pre, 0h, 24h |
Session
1: CK ↑ at 0h (+123 U·L-1, ±63, small),
remained ↑ 24h (+113, ±67, small). Session 2: CK ↑
at 0h (+154, ±72, moderate), remained ↑ 24h (+173,
±63, moderate). Indicates additive effect of congested schedules
on muscle damage. Session 1: T ↑ 0h (+36 pg·ml-1,
±32, small), ↓ 24h (-42, ±30, small). C ↓
0h (-0.14 μg·dl-1, ±0.09, small),
↓ 24h (-0.10, ±0.11, small). Session 2: T ↑
0h (+41, ±38, small), ↓ 24h (-76, ±37,
moderate). C ↓ 0h (-0.16, ±0.12, small), ↓ 24h
(-0.23, ±0.14, moderate). Confirms hormonal suppression with
congested SSGs. |
| Sparkes
et al., 2020b |
4v4 +
GK, same as above |
Salivary
testosterone (T), cortisol (C), T/C ratio pre, 0h, +2h, +24h |
T: RES+SSG
↑ at 0h (+17.0 ± 25.3 pg/ml, ns) vs SSG+RES
(-4.4 ± 32.5). Protocol difference at 0h = +21.4 ±
26.7 pg/ml (p=0.010, d=0.73, moderate). Both protocols ↓ at +2h
(-48.0 ± 35.9 pg/ml SSG+RES, p=0.001; -33.2
± 34.3 RES+SSG, p=0.019). At +24h, no difference. C:
Both protocols ↓ at +2h (SSG+RES -0.310 ±
0.192 μg/dl, p<0.001; RES+SSG -0.251 ±
0.178, p=0.001), recovered +24h. No protocol differences. T/C ratio:
Increased at +2h in both (SSG+RES +322 AU, p<0.001;
RES+SSG +262 AU, p=0.006). No protocol difference. |
| Sparkes
et al., 2022 |
4v4 +
GK, same as above |
Salivary
T, C, T/C pre vs post, across 2 weeks |
Pre reliability:
ICC very high (T 0.98, C 0.94, T/C 0.93). Pre→post reliability: ICC
very high (T 0.93, C 0.99, T/C 0.85). Typical changes: T stable (+3.5,
+3.1 pg/ml), C ↓ small (-0.038, -0.018 μg/dl),
T/C ↑ (+137, +75 AU). |
| Trecroci
et al., 2021 |
Match play
+48 h SST vs AR |
Blood at
-72 h, 0 h, +72 h: CK, CRP, IL-6, UA, sCr, cortisol, WBC,
neutrophils, lymphocytes, monocytes |
CK: Significant
interaction (F(1,16)=4.096, p=0.04, η2p=0.369). AR ↓
CK more (680 ±343 → 209 ±98 U/L, p<0.0001, ES=1.9)
vs SST (570 ±232 → 284 ±98, p=0.06, ES=1.6). Other
markers: Time effects (all ↑ 0h then ↓ +72h, p<0.01),
but no SST vs AR differences (p>0.05). E.g., cortisol ↑ pre→0h
(6.41 ±1.84 → 14.0 ±6.4 μg/dl), returned +72h
(5.52 ±1.29). IL-6 ↑ pre<1.84 → 3.74 ±2.3
pg/ml 0h, back <1.84 at +72h. UA ↑ 4.8 → 5.9
mg/dl 0h, back 5.0 +72h. |
