Sports and active hobbies

The most widely cited sport-by-sport comparison comes from the Copenhagen City Heart Study, which recorded participation and weekly duration for eight sports among 8,577 adults examined between 1991 and 1994 and followed them for all-cause mortality until 2017 [1]. The main comparison set 5,674 people who played at least one sport against 1,042 sedentary people. The fully adjusted model accounted for age, sex, total weekly leisure-time activity, smoking, education, income, alcohol intake and diabetes.

Estimated life expectancy gains compared with the sedentary group were 9.7 years for tennis, 6.2 for badminton, 4.7 for soccer, 3.7 for cycling, 3.4 for swimming, 3.2 for jogging, 3.1 for calisthenics and 1.5 for health-club activities such as treadmills and weights [1]. The corresponding hazard ratios (the death rate in one group relative to another; 0.36 means 64% lower) ranged from 0.36 for tennis to 0.86 for health-club activities, which was not statistically significant. The tennis estimate rested on 111 players and 16 deaths.

The authors reported that the sports involving two or more players and built-in social interaction, namely tennis, badminton and soccer, were associated with the largest gains, and that the differences were not explained by time spent exercising: the health-club group exercised for the most minutes a week and showed the smallest gain [1]. Adding social network to the model did not weaken the associations, and restricting the analysis to university graduates left the ranking of sports largely unchanged.

Several explanations have been proposed for the ranking of partner and team sports. Racket and team sports alternate short bursts of hard effort with recovery, a pattern similar to high-intensity interval training. A fixed game with other people may be kept up for more years than solo exercise. Social isolation predicts shorter life in many studies, and the Copenhagen authors named the social side of these sports as the explanation most in need of further study [1].

Selection is an equally plausible explanation. Tennis and badminton players may be healthier and better off in ways that questionnaires on education and income do not capture. People with heart disease or joint problems tend to stop court sports early, which leaves a healthier group still playing, while swimming may attract people who have moved away from other sports because of injury or illness. In the Copenhagen study, most participants also did other activities, and cycling made up 55% to 71% of total exercise time in every sport group, with the named sport accounting for about 20% [1]. An observational design cannot separate these explanations, and the per-sport groups are small enough that a few deaths either way would change the ranking.

A pooled analysis of English and Scottish national health surveys covered 80,306 adults (54% women, mean age 52) and six types of sport and exercise [2]. Compared with non-participants, all-cause mortality was lower for racquet sports (hazard ratio 0.53, 95% CI 0.40 to 0.69), swimming (0.72, 0.65 to 0.80), aerobics (0.73, 0.63 to 0.85) and cycling (0.85, 0.76 to 0.95). No significant association was found for football or running. For cardiovascular mortality, swimming (0.59), racquet sports (0.44) and aerobics (0.64) were associated with lower risk, while cycling, running and football were not. Racquet sports placing first in a second, independent population is the most consistent finding across sport-type studies.

Running was examined in 55,137 US adults aged 18 to 100 (mean age 44), followed for an average of 15 years, during which 3,413 died [3]. About 24% ran. Runners had 30% lower all-cause and 45% lower cardiovascular mortality than non-runners, equivalent to about 3 years of life expectancy. The benefit was similar across all levels of running time, distance, frequency and speed, and running less than 51 minutes a week, once or twice a week, or at under 6 miles an hour was enough to show the association. People who kept running over the study period had 29% lower all-cause and 50% lower cardiovascular mortality than those who never ran.

Cycling appears in the data as transport as well as sport. Among 263,450 UK Biobank participants followed for a median of 5.0 years, cycling to work was associated with lower all-cause mortality (hazard ratio 0.59, 95% CI 0.42 to 0.83) and lower cancer incidence (0.55, 0.44 to 0.69) than commuting by car or public transport [4]. Walking to work was associated with less cardiovascular disease (0.73, 0.54 to 0.99) but not with lower all-cause mortality. UK Biobank volunteers are healthier than the general population, and the follow-up was short.

Dancing was studied in a pooled analysis of 11 British population surveys conducted from 1995 to 2007, covering 48,390 adults aged 40 and over who were free of cardiovascular disease at the start [6]. Over 444,045 person-years, 1,714 people died of cardiovascular disease. After adjustment for age, sex, socioeconomic status, smoking, alcohol, body mass index, chronic illness, psychological distress and total physical activity, moderate-intensity dancing was associated with 46% lower cardiovascular mortality (hazard ratio 0.54, 95% CI 0.34 to 0.87), compared with 33% for moderate-intensity walking (0.67, 0.52 to 0.87). Light-intensity dancing and walking showed no association. The authors suggested short high-intensity bouts, lifelong participation and social benefits as possible reasons, without testing them.

Gardening has one randomised trial. In Denver and Aurora, Colorado, 291 adults (mean age 41.5, 82% women) who had not gardened in the previous two years were randomly assigned either a community garden plot or a place on the waiting list [7]. Over the growing season, the gardening group increased moderate-to-vigorous activity by an average of 5.8 minutes a day relative to controls and fibre intake by 1.41 g a day, and reported larger reductions in stress and anxiety. Body mass index and waist size did not change significantly, and the trial was too short to measure disease outcomes.

Hiking is usually classified as walking in population studies and has not been reported as a separate category in the studies above. Its evidence base is therefore that of walking and daily steps, with the addition of hills and uneven ground that increase intensity.

A study of 315,059 US adults aged 50 to 71 at enrolment in 1995 and 1996, who reported their leisure-time activity at ages 15 to 18, 19 to 29, 35 to 39 and 40 to 61, examined whether activity taken up later in life is associated with lower mortality [5]. By the end of 2011, 71,377 had died. Compared with people who were inactive throughout adulthood, those who maintained high activity at every age had 36% lower all-cause mortality (hazard ratio 0.64, 95% CI 0.60 to 0.68), and those who were inactive for most of adulthood but increased activity at ages 40 to 61 had 35% lower mortality (0.65, 0.62 to 0.68). Cardiovascular mortality showed the same pattern, at 0.58 and 0.57.

Activity in earlier decades was recalled at the start of the study, often 30 or more years after the fact, which limits precision. People who take up activity in midlife may differ in other ways from those who remain inactive. The result is consistent with the wider evidence on exercise and longevity, in which the largest differences in mortality are between inactive people and those who do some activity.