Table 1.

Cardiac fibrosis in response to exercise.

Exercise model	Outcome	Species	Age (week)	Sex
Swimming (50 min/day for 4 weeks)57	Exercise reduced isoproterenol-induced cardiac fibrosis in wild-type but not in AMPK knockout mice	Mice	10	Male
Treadmill (40 min, 4 days/week for 5 weeks)58	Exercise did not prevent doxorubicin-induced fibrosis or ejection fraction. It preserved cardiac strain, alleviated doxorubicin-induced atrophy	Mice	8	Male
Treadmill (velocity increased every 3 min to max after warmup at Weeks 0 and 4)60	Exercise reduced doxorubicin-induced fibrosis and preserved myofibril integrity and sarcomere organization	Rats	12	Male
Treadmill (1 week of acclimation and 4 weeks of moderate intensity for 60 min/day for 28 days)59	Exercise reduced doxorubicin-induced gene expressions of fibrosis factors, cardiac remodeling factors, and inflammatory mediators	Mice	Unclear	Male
Swimming (1 h/day, 5 days/week for 14 weeks, with 4% body weight load attached to tail)61	Exercise improved myocardial tolerance to doxorubicin-induced damaged	Mice	6–8	Male
Treadmill (1 week of training, 50 min, 5 days/week for 8 weeks)63	Exercise preserved cardiac function and reduced collagen volume fraction after myocardial infarction	Rats	7	Male
Treadmill (speeds increased every 2 weeks until reaching 27 m/min, 60 min, 5 days/week for 8 weeks)64	Exercise reduced cardiac fibrotic-related protein expressions in spontaneously hypertensive ovariectomized rats	Rats	15	Female
Swimming (speeds increased for 2 weeks, then 90 min/day, twice daily for 2 weeks)50	Exercise increased heart weight and succinate dehydrogenase but did not change myofibrillar ATPase	Mice	8	Female
Treadmill (training for 1 week then 45 min, 5 days/week for 10 weeks up to 70% of max oxygen capacity)65	Exercise reduced collagen deposition and cross-linking in left ventricular septum but not left ventricular or right ventricular free wall in older rats	Rats	23 and 111	Male
Treadmill (15, 13, and 10 m/min, respectively, for 50 min/day, progressively increased with 30, 24, and 15 m/min for 60 min/day, 5 days/week at termination)66	Exercise prevented age-related decline mRNA expressions of fibrillar collagens Type 1 and Type 3 in left ventricle	Rats	20, 60, and 104	Female
Treadmill (1 week of training, 60 min, 5 days/week for 8 weeks, then 4 days/week until 48 h before sacrifice)67	Exercise reduced fibrosis and advanced glycation end products associated with aging and diabetes	Rats	28 and 116	Male
Treadmill (1 week of training 15 min/day, then 8 weeks of moderate intensity exercise 60 min/day, 5 days/week)68	Exercise reversed diabetes-induced alterations in factors of myocardial fibrosis	Rats	8	Male
Treadmill (4 weeks starting at 30 min/day working up to 60 min/day by Week 5, 5 days/week)69	Exercise restored bioavailability of hydrogen sulfide in aged rats; likely protective against cardiac fibrosis. Exercise also reduced expression of Collagen I and α-smooth muscle actin in hearts of aged rats	Rats	12 and 92	Male
Treadmill (45 min, 5 days/week for 7 weeks)70	Exercise reduced aged-related fibrosis and dysregulation of matrix metalloproteinase	Rats	12 and 124	Unclear
Treadmill (60 min, 5 days/week for 12 weeks)71	Exercise reduced age-related cardiac remodeling and fibrosis in the left ventricle	Rats	12 and 96	Unclear
Treadmill (60 min, 5 days/week for 10 weeks)54	Exercise did not change the ratio of Collagen III/Collagen I in the heart after isoproterenol stimulation	Rats	Unclear	Male

Abbreviation: AMPK = adenosine monophosphate-activated protein kinase.