ORIGINAL ARTICLES   

The Journal of Sports Medicine and Physical Fitness 1998 December;38(4):310-6

Copyright © 1999 EDIZIONI MINERVA MEDICA

lingua: Inglese

Exercise without dietary restriction as a means to long-term fat loss in the obese cardiac patient

Mertens D. J. ¹, Kavanaghi T. ², Campbell R. B. ¹, Shephard R. J. ^{1, 3, 4, 5}

¹ Toronto Rehabilitation Centre, Toronto, ON; ² Department of Medicine, Faculty of Medicine, University of Toronto, ON; ³ Faculty of Physical Education and Health, Faculty of Medicine, University of Toronto, ON; ⁴ Department of Public Health Sciences, Faculty of Medicine, University of Toronto, ON; ⁵ Health Studies Programme, Brock University, St. Catharines, ON, Canada

Back­ground. To ­examine the ­effects of a 12-­month ­daily ­walking pro­gram ­without die­tary restric­tion on the meta­bolic ­rate, ­body com­po­si­tion and ­blood ­lipid pro­file of over­weight and mod­er­ately ­obese ­patients fol­lowing myo­car­dial infarc­tion.
­Methods. ­Design: lon­gi­tu­dinal ­training (pre­lim­i­nary ­study). Set­ting: out-­patient car­diac reha­bil­i­ta­tion pro­gram. Par­tic­i­pants: ­twelve con­sec­u­tive vol­un­teers (8M, 4F) ­with a ­body ­mass ­index of 25-40 kg/m2. Rel­a­tive to ­average car­diac ­patients, the men but not the ­women ­were sig­nif­i­cantly ­heavier (100.8 vs 77.4 kg [M], 70.7 vs 74.2 kg [F]) and ­fatter (hydro­static esti­mate of ­body fat 34.0% vs 23.1% [M]; 38.3% vs 36.3% [F]) ­than the gen­eral car­diac ­patient. Meas­ures: ­body ­mass, hydro­static ­weighing, tri­gly­ce­rides, ­total, HDL- and LDL-cho­les­terol, ­resting and ­peak ­oxygen ­intake, one ­week ­food ­intake ­diaries.
­Results. ­Daily ­walking ­increased pro­gres­sively ­from 20 min to 43 min ­over 3 ­months, and was ­then ­held con­stant for 9 ­months.
­Peak ­aerobic ­power ­increased 24%, ­from 19.9 to 24.6 ml/[kg.min] (p<0.001). ­Resting ­oxygen ­intake ­rose ­from 3.1 to 3.4 ml/[kg.min], (p<0.05). ­Energy ­intake ­increased ­from 6.10 to 6.57 MJ/day, but ­body ­mass ­decreased by an ­average of 4.5 kg (p<0.05, 4.1 kg [M], 5.1 kg [F]), and ­body fat con­tent dimin­ished ­from 35.4 to 33.2% (p<0.02, 1.8% [M], 3.2% [F]), ­with no ­change in ­lean ­body ­mass (57.7 vs 57.8 kg). Tri­gly­ce­rides dimin­ished ­from 2.63 to 2.28 ­mmol/L (p<0.005). ­Total and LDL-cho­les­terol ­also ­tended to ­change favor­ably (­from 6.15 to 5.80 and 4.44 to 3.80 ­mmol/L respec­tively, but HDL-cho­les­terol was ­unchanged).
Con­clu­sions. A ­daily ­walking pro­gram ­without die­tary restric­tion ­induces a favor­able ­change in ­body com­po­si­tion and ­lipid pro­file in mod­er­ately ­obese car­diac ­patients. An exer­cise-­induced ­increase of ­resting metab­olism appar­ently ­makes an impor­tant con­tri­bu­tion to ­this out­come.