Short-term HIIT and Fat max training increase aerobic and metabolic fitness in men with class II and III obesity.
OBJECTIVE
To compare the effects of two different 2-week-long training modalities [continuous at the intensity eliciting the maximal fat oxidation (Fatmax) versus high-intensity interval training (HIIT)] in men with class II and III obesity.


METHODS
Nineteen men with obesity (BMI ≥ 35 kg · m(-2)) were assigned to Fatmax group (GFatmax) or to HIIT group (GHIIT). Both groups performed eight cycling sessions matched for mechanical work. Aerobic fitness and fat oxidation rates (FORs) during exercise were assessed prior and following the training. Blood samples were drawn to determine hormones and plasma metabolites levels. Insulin resistance was assessed by the homeostasis model assessment of insulin resistance (HOMA2-IR).


RESULTS
Aerobic fitness and FORs during exercise were significantly increased in both groups after training (P ≤ 0.001). HOMA2-IR was significantly reduced only for GFatmax (P ≤ 0.001). Resting non-esterified fatty acids (NEFA) and insulin decreased significantly only in GFatmax (P ≤ 0.002).


CONCLUSIONS
Two weeks of HIIT and Fatmax training are effective for the improvement of aerobic fitness and FORs during exercise in these classes of obesity. The decreased levels of resting NEFA only in GFatmax may be involved in the decreased insulin resistance only in this group.
Institute of Sport Sciences University of Lausanne (ISSUL), University of Lausanne, Lausanne, Switzerland.|Department of Physiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland.
Stefano
S
Lanzi
Pulmonary Rehabilitation Department, San Giuseppe Hospital, Istituto Auxologico Italiano Piancavallo, Verbania, Italy.
Franco
F
Codecasa
Pulmonary Rehabilitation Department, San Giuseppe Hospital, Istituto Auxologico Italiano Piancavallo, Verbania, Italy.
Mauro
M
Cornacchia
Molecular Biology Laboratory, San Giuseppe Hospital, Istituto Auxologico Italiano Piancavallo, Verbania, Italy.
Sabrina
S
Maestrini
Orthopaedic Rehabilitation Unit and Clinical Lab for Gait and Posture Analysis, San Giuseppe Hospital, Istituto Auxologico Italiano Piancavallo, Verbania, Italy.
Paolo
P
Capodaglio
Medicine Rehabilitation Department, San Giuseppe Hospital, Istituto Auxologico Italiano Piancavallo, Verbania, Italy.
Amelia
A
Brunani
Pulmonary Rehabilitation Department, San Giuseppe Hospital, Istituto Auxologico Italiano Piancavallo, Verbania, Italy.
Paolo
P
Fanari
Pulmonary Rehabilitation Department, San Giuseppe Hospital, Istituto Auxologico Italiano Piancavallo, Verbania, Italy.
Alberto
A
Salvadori
Institute of Sport Sciences University of Lausanne (ISSUL), University of Lausanne, Lausanne, Switzerland.|Department of Physiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland.
Davide
D
Malatesta
D000328:Adult; D015415:Biomarkers / Q000097:blood; D015444:Exercise / Q000502:physiology*; D005230:Fatty Acids, Nonesterified / Q000097:blood; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D050356:Lipid Metabolism / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000378:metabolism* / Q000628:therapy*; D010084:Oxidation-Reduction; D010101:Oxygen Consumption / Q000502:physiology*
D015415:Biomarkers; D005230:Fatty Acids, Nonesterified; D007328:Insulin