METABOLIC EFFECTS OF HIGH-INTENSITY INTERVAL TRAINING … · Weight (kg) 100.82 ±13.46 88.10...
Transcript of METABOLIC EFFECTS OF HIGH-INTENSITY INTERVAL TRAINING … · Weight (kg) 100.82 ±13.46 88.10...
Results
Table 1: Participant Characteristics (Mean ± SD)Male (n=33) Female (n=33)
Age (yrs) 36.82 ± 6.65 36.67 ± 5.37Height (cm) 178.54 ± 6.87 164.34 ± 6.56Weight (kg) 100.82 ± 13.46 88.10 ± 13.08BMI (kg/m2) 31.58 ± 4.09 32.48 ± 4.34%BF 31.13 ± 5.47 40.89 ± 6.61
PurposeTo evaluate the modulatory effects of sex on body composition and metabolism following eight weeks of HIIT and/or essential amino acid (EAA) supplementation in overweight and obese adults.
Indirect CalorimetryResting Metabolic Rate (RMR; kcal/day)
Substrate Metabolism (RER; a.u.) Carbohydrate vs. Fat Metabolism
Cardiorespiratory Fitness (VO2)
32
33
34
35
kg
FM
33
34
35
36
37
%
%BF
58
59
60
61
62
kg
FFM HIITEAAHIIT+EAACON
Figure 1: Body composition responses at baseline, 4wks, and 8wks when adjusted for baseline values. No significant interaction effect for sex between groups or across time for any variable (p>0.05).
-200.0-150.0-100.0-50.0
0.050.0
100.0150.0200.0250.0
ΔRM
R (k
cal/d
)
MALE
-0.10
-0.05
0.00
0.05
0.10
ΔR
ER (a
.u.)
* *
*
-200.0
-100.0
0.0
100.0
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300.0
ΔRM
R (k
cal/d
)
FEMALE
-0.10
-0.05
0.00
0.05
0.10
ΔRER
(a.u
.)
HIITEAAHIIT+EAACON
*
Figure 3: Female metabolic change from 0-8 wksΔRMR ΔRER
HIIT 33.5 ± 40.4 -0.05 ± 0.02*
EAA -61.1 ± 46.8 -0.01 ± 0.02
HIIT+EAA 47.6 ± 45.5 -0.01 ± 0.02
CON 103.3 ± 62.7 0.01 ± 0.03
Figure 2: Male metabolic change from 0-8 wksΔRMR ΔRER
HIIT 133.9 ± 45.5* -0.03 ± 0.02
EAA 92.2 ± 39.0* -0.04 ± 0.02*
HIIT+EAA 51.6 ± 42.5 -0.03 ± 0.02
CON 55.1 ± 62.7 -0.02 ± 0.03
Katie R. Hirsch, Casey E. Greenwalt, Hannah E. Saylor, Courtney H. Harrison, Lacey M. Gould, Alyson G. Nelson, Dalton W. Wheeless, Gabrielle J. Brewer, Malia N.M. Blue, Abbie E. Smith-Ryan
• Paradoxical responses to moderate intensity exercise (i.e. gaining bodyfat) have previously been reported in women
• High-intensity interval training (HIIT) is an effective way to increasecardiorespiratory fitness and promote body composition changes in avariety of populations.
• Recent evidence in mice suggests that HIIT may overcome paradoxicalresponses, promoting positive changes in both men and women.
• Essential amino acids (EAA) support muscular and metabolic adaptationthrough the promotion of muscle protein turnover and increasing fatoxidation.
• HIIT, in combination with EAA, may create a metabolic environmentthat supports muscular adaptation.
Introduction
Experimental Design
• Despite no changes in body composition, HIIT improved RMR and fatoxidation in men and women, respectively. HIIT also improvedcardiorespiratory fitness in both men and women; adaptations may occurmore quickly in men, especially with EAA.
Conclusion
METABOLIC EFFECTS OF HIGH-INTENSITY INTERVAL TRAINING AND ESSENTIAL AMINO ACID SUPPLEMENTATION: MODULATORY EFFECTS OF SEX
Funded by a Doctoral Student Research Grantfrom the National Strength and ConditioningAssociation Foundation
Methods: all measurements completed at baseline, 4 weeks and 8 weeks
4-Compartment Body Composition ModelFat Mass (kg) = 2.748(BV) – 0.699(TBW) + 1.129(Mo) – 2.051(BM)
Percent Body Fat = (FM/BM) × 100
Fat-Free Mass (kg) = BM – FM
Mean changes adjusted for baseline values ± SE [95% CI]; *significant change from 0-8 wks based on 95% CI
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Base 4wk 8wk
VO
2 (m
l/kg/
min
)
A) Male: VO2adjusted means
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Base 4wk 8wk
VO
2 (m
l/kg/
min
)
B) Female: VO2adjusted means
HIITEAAHIIT+EAACON
* §, $ #, §
Figure 4: Male (A) and female (B) cardiorespiratory fitness at baseline, 4wks, and 8wks. Values presentedare ANCOVA means adjusted for baseline values. *significant change from 0-4 weeks for HIIT+EAA;#significant change from 4-8 weeks for HIIT; §significant change from 0-8 weeks for HIIT andHIIT+EAA; $significant change from 0-8 weeks for EAA; significance based on adjusted mean change and95% CI.
RANDOMLY ASSIGNED TO 8-WEEKS OF:
2 days / week on cycle ergometer[6-10 × (1min @ 90%; 1min rest)]HIIT
Twice daily supplementation (7.2g EAA Daily)EAA
2 days / week on cycle ergometer+ Twice daily supplementationHIIT+EAA
No InterventionMaintained normal diet and exercise habitsCON
EAA Supplement
Practical Applications
HIIT is an EFFECTIVE and FEASIBLEapproach to increase
CARDIORESPIRATORY FITNESS and promote increases in
METABOLIC RATE and FAT OXIDATION in both MEN and
WOMEN
Twice daily EAA SUPPLEMENTATION
may also stimulate positive metabolic adaptations, increasing
METABOLIC RATE and FAT OXIDATION, independent of
exercise.
BV = Body Volume; TBW = total body water; Mo = Bone Mineral; BM = Body Mass