Help speeding up this query - maybe need another index?

Here's my SQL query.  I don't think it's too gigantic, but it is kind
of beastly:

SELECT COUNT(r) FROM trainer_hand_results r, trainer_scenarios s,
trainer_scenario_stats stats WHERE r.user_id=1 AND
r.trainer_scenario_id=s.id AND s.id=stats.trainer_scenario_id AND
r.action=stats.correct_action;

When I EXPLAIN it, I get:

 Aggregate  (cost=18.12..18.13 rows=1 width=32)
   ->  Nested Loop  (cost=0.00..18.12 rows=1 width=32)
         ->  Nested Loop  (cost=0.00..12.28 rows=1 width=40)
               Join Filter: (("outer"."action")::text =
("inner".correct_action)::text)
               ->  Seq Scan on trainer_hand_results r
(cost=0.00..6.56 rows=1 width=181)
                     Filter: (user_id = 1)
               ->  Index Scan using
trainer_scenario_stats_trainer_scenario_id_index on
trainer_scenario_stats stats  (cost=0.00..5.71 rows=1 width=149)
                     Index Cond: (stats.trainer_scenario_id =
"outer".trainer_scenario_id)
         ->  Index Scan using trainer_scenarios_pkey on
trainer_scenarios s  (cost=0.00..5.82 rows=1 width=4)
               Index Cond: ("outer".trainer_scenario_id = s.id)
(10 rows)

I don't have a lot of experience with getting queries to go faster.
The things that jump out at me though are two nested loops and a
sequential scan.  What could I do to speed this up?

Pat